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HERCBIOS.ASM
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Assembly Source File
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1986-11-22
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73KB
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2,460 lines
#!/bin/sh
# shar: Shell Archiver
# Run the following text with /bin/sh to create:
# read.me
# hercbios.doc
# hercules.prg
# gchar.asm
# graph.asm
# hcharset.asm
# hercbios.asm
# hercbios.aut
# hercbios.h
# hercdemo.asm
# hercmake.att
# hercmake.lcm
# hercpixl.dc
# hercpixl.lc
# testpix.c
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > read.me
X
X H E R C U L E S
X ---------------
X
XThis .ARC file contains two sets of information:
X
X
X - HERCULES.PRG is a memo from Bob Morse and a note from me
X explaining the programming parameters for the Hercules (and
X clone) graphics board. His information is especially useful
X because he lists the internal parameters which must be
X programmed into the 6845 chip to get graphics mode to work
X correctly. Please report any problems with this information to
X me at DECWET::BROWN or Bob at LEWS2::MORSE.
X
X HERCDEMO.COM (source included as HERCDEMO.ASM) is a quick and
X dirty demo program I wrote to help me understand the way the
X HERCULES card works, and use graphics character generation.
X
X
X - HERCBIOS.COM plus support sofware. HERCBIOS.COM is a terminate-
X and-stay-resident program which takes over some functions from
X ROM BIOS INT 10h, providing IBM-compatible graphics modes 6 (640
X by 200) and 7 (monochrome text) and adding mode 8: Hercules
X graphics (720 by 348). Other functions are just passed through
X to the existing ROM BIOS.
X
X HERCBIOS was written by Dave Tutelman at AT&T in New Jersey, and
X the software came to me via net.micro.pc, hot off the wire two
X days ago. I've included his note and banner as HERCBIOS.AUT.
X
X HERCBIOS.DOC explains the operation of the program in detail.
X
X HCHARSET.ASM is a simple test program to demonstate IBM and
X HERCULES modes.
X
X There is also a C program which gives a more extended demo of
X the facility: TESTPIX.C. TESTPIX must be linked with another C
X module, HERCPIXL, which provides the actual linkages to INT 10h.
X Since system calls are implementation specific, there are two
X versions of this module: HERCPIXL.DC and HERCPIXL.LC.
X HERCPIXL.DC is DeSmet C compatible and HERCPIXL.LC is Lattice C
X compatible. I've included TESTPIX.EXE (build with Lattice) so
X you can test the software if you don't have C.
X
X Finally, there are two make files: HERCMAKE.ATT and
X HERCMAKE.LCM. HERCMAKE.ATT is a make file for a make program
X which looks UNIX compatible, so I called it ".ATT".
X HERCMAKE.LCM is a make file for the Larry Campbell MAKE program
X I use. In either case, you will have to use the -f switch
X invocation of MAKE. E.g: MAKE -f HERCMAKE.LCM HERCBIOS.COM.
X
X HERCBIOS.COM seems to work quite nicely as advertised, but I
X must warn you that there are some functions which are not yet
X implemented -- scrolling in graphics mode, for one. I'm sure
X Dave will continue to enhance it and hope to get future updates.
X In the meantime, if anyone gets brave and tackles scrolling, put
X the updates on PAR5!
X
X
X-Reid Brown
X 6-Sep-1986
X DECWET::BROWN
SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > hercbios.doc
X
X
X ***** HERCBIOS *****
X BIOS PATCH FOR THE HERCULES BOARD
X
X Dave Tutelman 1986
X
X
X
X The accompanying program is a front end to the INT 10 (VIDEO)
X functions of the DOS BIOS, so that the important functions work
X on a Hercules graphics board or its clones. (It was developed on
X a SuperComputer clone of a Hercules) It is a
X terminate-and-stay-resident program, that is installed by being
X called; it is NOT a DOS driver. If you want it installed at boot,
X include it in AUTOEXEC.BAT, not CONFIG.SYS.
X
X WHAT IT'S GOOD FOR
X
X The major strength of this program is that it will allow you to
X write programs for the Hercules board that run in graphics mode,
X and still write text easily on the graphics screen. With it, you
X can program in those higher-level language processors that use
X the DOS or BIOS calls for display, using their standard I/O calls
X to write text to the graphics screen. (For a list of known
X compatible and incompatible languages, see the section later in
X this manual.)
X
X A second use of this program is to allow the running of existing
X graphics programs that use the BIOS calls for ALL screen display.
X It will NOT allow most commercial graphics programs written for
X the the Color Graphics Adapter (CGA) to run on the Hercules
X board. That is because most graphics programs write directly to
X the video memory instead of using the BIOS calls. The only
X existing graphics program that this has been tested against is
X PC-LISP; that is the only graphics program I've encountered that
X uses the BIOS exclusively.
X
X
X HOW IT WORKS
X
X HERCBIOS is a terminate-and-stay-resident program that intercepts
X all calls to Interrupt 10H, the BIOS video services. It will
X either process the interrupt or pass the call on to the real
X BIOS, depending on whether something specific to the Hercules
X board needs to be done. Specifically, HERCBIOS handles the
X interrupt itself if (1) the board is in graphics mode, or (2) the
X BIOS call is a request to enter graphics mode.
X
X Two graphics modes are recognized and processed by HERCBIOS:
X
X Mode 6 - IBM Hi-res mode: This uses part of the 720x348
X Hercules raster as a 640x200 IBM-compatible graphics screen.
X It will work with programs for the IBM CGA and its clones,
X provided they use the BIOS services for their graphics
X display. (Note - such programs are rare.)
X
X Mode 8 - Hercules-specific mode: This uses the full
X
X - 1 -
X
X
X Hercules raster.
X
X Actually, both modes are quite capable of putting a pixel
X anywhere on the Hercules raster. The major difference is that
X Mode 6 draws characters in an 8x8 pixel box (like the CGA), while
X Mode 8 uses the finer resolution of the Hercules board to improve
X legibility by using a 12x8 pixel box for characters. In either
X mode, more characters than 25x80 will fit on the screen. Mode 6
X supports 43x90 characters on the screen (but 25x80 inside the
X 640x200-pixel sub-screen); Mode 8 supports 29x90 characters.
X
X The functions implemented by HERCBIOS are:
X
X Fn 0 - Set mode (6, 7, or 8)
X Fn 2 - Set cursor position
X Fn 3 - Read cursor position
X Fn 5 - New display page
X Fn 9 - Write character with attribute
X Fn 10 - Write character
X Fn 12 - Write pixel
X Fn 13 - Read pixel
X Fn 14 - Teletypewriter-style character write
X Fn 15 - Get video status
X
X Check your System Programmers' Guide for the use of these BIOS
X functions.
X
X A number of properties of the alphanumeric display are not
X supported by the hardware when you enter graphics mode. For
X instance, the cursor is not shown in graphics mode, nor are all
X of the character attributes. HERCBIOS does its best to emulate
X the alphanumeric mode, but it cannot implement a cursor or the
X blinking or bold attributes. The table below shows the "best
X shot" that HERCBIOS takes at character attributes:
X
X CODE USUALLY MEANS IBM MODE HERC MODE
X 00 invisible invisible invisible
X 01 underline [normal] underline
X 07 normal normal normal
X 0F hi-intens [rev video] [rev video]
X 70 rev video rev video rev video
X
X
X Anything else displays as normal
X
X The teletypewriter-style output protects the bottom line on the
X screen as an unscrolled line, for status messages, function key
X labels, etc. This is non-standard, but I like it. (And we do have
X more rows than the CGA display. It's the 43rd line that isn't
X scrolled.)
X
X
X
X
X
X
X
X - 2 -
X
X
X MAKING AND INSTALLING THE PROGRAM
X Making the .COM File from Assembler Source
X
X HERCBIOS was originally developed on ASM 1.0. The version
X included with this uses MASM 4.0. I don't know for sure whether
X it will assemble with other versions of assembler.
X
X The commands for making HERCBIOS.COM from the source are in the
X MAKEFILE included with the distribution. I run it with NDMAKE, an
X excellent MS-DOS shareware MAKE from Don Knellers, but it should
X be easy to adapt to your own favorite MAKE. If you make it by
X hand, the commands are:
X
X masm hercbios;
X masm gchar;
X masm graph;
X link hercbios gchar graph, hercbios.exe;
X exe2bin hercbios.exe hercbios.com
X del hercbios.exe
X
X If you have a machine whose processor is an iAPX 286, 186, or
X 188, you may be able to get some increased performance and a
X smaller .COM file by editing one character in the header file
X hercbios.h. Simply remove the ";" that comments out the
X definition of iAPX286. That will allow some non-8088 instructions
X to assemble, as well as changing some code that was optimized for
X speed (at the expense of storage and beauty) on the 8088. (This
X option is known to assemble and link, but has not been tested; I
X have no access to a 286 machine with Hercules graphics.)
X
X
X Installing HERCBIOS.COM
X
X Once you have HERCBIOS.COM, store it where your PATH will find it
X and add the line
X
X HERCBIOS
X
X to your AUTOEXEC.BAT file somewhere after the PATH command. This
X will cause it to be installed during boot, so it will be there
X whenever you run your graphics programs. (Its presence won't
X affect operation of your computer in alphanumeric mode, since it
X passes on to the normal BIOS anything that's not in graphics
X mode.)
X
X I am including a couple of demonstration/test programs in this
X distribution, so that you can:
X - See how to write programs for HERCBIOS.
X - Test to assure that it runs with your computer and monitor.
X The programs can be run in their executable form and their source
X can be examined.
X
X
X
X
X
X
X - 3 -
X
X
X COMPATIBILITY AND INCOMPATIBILITY
X
X HERCBIOS has been tested on a Hercules board in an IBM PC-XT, a
X Hercules-compatible board I built from a SuperComputer bare
X board, and a Leading Edge XT clone. The current version works
X with all of these, but I have a homebrew monitor that has trouble
X syncing to the higher sweep rate of the monochrome display. If
X you have trouble with the stability of your image, try fiddling
X with the parameters for the 6845 display chip. They are in the
X file HERCBIOS.ASM, in the "db" statement defining vid_parm_table
X at the end of Function 0 (Set Video Mode). I have left in (but
X commented out) the set of parameters that works on my homebrew
X monitor.
X
X I have written programs using HERCBIOS in a number of languages.
X Here are some of the caveats I'd like to pass on:
X
X - Things are fine using INT 10h calls in assembler. (No big
X surprise.)
X
X - Turbo Pascal works with HERCBIOS, with one caveat (at least
X for releases 1 and 2). The Pascal cursor function GoTOXY will
X home the cursor if presented with x>80 or y>25. To make full
X use of the 29x90 or 43x90 screen, you will have to write your
X own version of GoTOXY, using Turbo's machine language escape
X to issue the INT 10h.
X
X - I've written a little in Microsoft C 3.0. No problems so far.
X
X - The TESTPIX program was written in deSmet C 2.4. It worked
X fine, with one caveat. The console I/O routine getchar()
X seems to write to display memory (perhaps as part of keyboard
X echo). This can interfere with what is displayed on the
X Hercules board display page 1. (I had no problems on page
X 0.)
X
X - Forget about using it with BASICA or GWBASIC. Microsoft BASIC
X graphics routines write directly to display memory,
X completely bypassing the BIOS.
X
X
X USE AND ENJOY!
X
X Bug reports to:
X Dave Tutelman
X 16 Tilton Drive
X Wayside, NJ 07712
X
X
X Currently receive EMail at ...!mtuxo!mtuxt!dmt
X
X
X Flames to:
X /dev/null
X
X
X
X - 4 -SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > hercules.prg
X Hercules Monochrome Graphics Card Programming
X ---------------------------------------------
X
X provided by
X
X Robert Morse MLO5-2/B6 LEWS2::MORSE
X
XThe board configuration is controlled by the write-only control register
Xat port 03BF. All bits are set to zero upon power-up, which limits
Xthe board to text mode (it will pass IBM monochrome display adapter
Xdiagnostics only while all bits are zero).
X
XBit Description
X--- -----------
X 0 0=disable setting of graphics mode; 1=allow graphics mode.
X 1 0=disable page one (allows coexistence with a color graphics
X board); 1=enable page one (required to run Lotus 1-2-3).
X 2..7 (not used)
X
X
X
XModes are controlled by the write-only control register at port 03B8. All
Xbits are set to zero upon power-up.
X
XBit Description
X--- -----------
X 0 (not used)
X 1 0=text; 1=graphics.
X 2 (not used)
X 3 0=blank screen; 1=activate screen.
X 4 (not used)
X 5 0=disable text blink; 1=enable text blink.
X 6 (not used)
X 7 0=page zero at B0000h; 1=page one at B8000h.
X
X
X
XTable of 6845 values (all values in hexadecimal):
X
XRegister Text Graphics
X------------------------- ---- --------
X 0 Total chars/row -1 61 35
X 1 Visible chars/row 50 2D
X 2 Hsync position 52 2E
X 3 Hsync width 0F 07
X 4 Total rows -1 19 5B
X 5 Additional scan lines 06 02
X 6 Visible rows 19 57
X 7 Vsync position 19 57
X 8 Interlace control 02 02
X 9 Lines/row -1 0D 03
X A Top cursor scan 0B 00
X B Bottom cursor scan 0C 00
X C Display origin 00 00
X D Display origin 00 00
X
XIn text mode, each character time is 0.5625 microseconds and a character is
X9 dots wide and 14 dots high. The controller is programmed for 25
Xdisplayed rows of 14 scan lines each. There are 350 visible scan lines and
X370 total scan lines.
X
X
XIn graphics mode, each character time is 1.000 microseconds and a character
Xis 16 dots wide and 4 dots high. The controller is programmed for 87
Xdisplayed rows of 4 scan lines each. There are 348 visible scan lines and
X370 total scan lines. Each row has 45 displayed characters of 16 bits,
Xgiving 720 dots/row.
X
X
X<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
X Note on Addressing the Screen
X -----------------------------
X
XThe preceding paragraph gives a hint about pixel addresses in graphics
Xmode. I looked through the HERCBIOS sources and then wrote a program
X(HERCDEMO.ASM) to help me understand this. Here's how screen addressing
Xworks:
X
X o Although you might think of graphics mode as pure bits, the 6845
X chip always thinks in term of characters. When you switch to
X graphics mode, the characters are 16 bits wide by 4 bits high.
X Thus, in graphics mode the screen has 87 rows of "characters"
X and each row is 45 characters wide, for 720x348 pixels.
X
X o For a reason unknown to me (probably speed of memory access),
X each of the four scan lines in a graphics character is stored in
X a different "bank" or 2000h section of the screen buffer. All
X 87 scan line 0s are stored from 0-2000h, all scan line 1s from
X 2000h-4000h, all scan line 2s from 4000h-6000h, and all scan
X line 3s from 6000h-8000h.
X
X o Within a bank of memory (representing one set of scan lines),
X each row is 45 words or 90 bytes wide. Rows follow each other
X with no intervening space. So, assuming row numbers from 0 to
X 86, the 5th graphics character in row 40 is composed of four
X scan lines, each 16 bits wide, located at the following memory
X addresses (offsets from the beginning of the screen buffer):
X 40*90 = 3600 (offset in any bank to row 40)
X 4*2=8 (5th graphics char = (n-1)*2 bytes/char)
X Scan line 0: locations 3608,3609
X Scan line 1: 2000h (8192) + 3608,9 = 11800,11801
X Scan line 3: 4000h (16384) + 3608,9 = 19992,19993
X Scan line 4: 6000h (24576) + 3608,9 = 28184,28185
X
X o Computing a pixel location is a little harder, but still fairly
X straightforward. Say you want to address the bit at 300,300
X with a point of origin at the upper left. 300 scan lines down
X from the top is 300/4 = 75 (no remainder), which is scan line 0
X of row 75. 300 bits into the line is 300/8 = 37 remainder 4.
X The bit you want is in bank 0 (0-2000h) since it is scan line 0,
X offset by 75*90 =6750 for the row, plus 37 for the byte within
X the row, or byte offset 6787 from the beginning of that page in
X screen memory. Within that byte, you want to set/reset bit 4.
X
X
XWell, that should cover it. If you should discover that I got any of
Xthis wrong, send me mail.
X
X-Reid Brown
XDECWET::BROWN
SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > gchar.asm
X;********************************************************************
X;*
X;* GRAPHIC CHARACTER HANDLING
X;*
X;* Dave Tutelman - 8/86
X;*
X;*-------------------------------------------------------------------
X;*
X;* Fn 6 Scroll up - not yet implemented
X;* Fn 7 Scroll down - not yet implemented
X;* Fn 9 Write character with attribute
X;* Fn 10 Write character normal
X;* Fn 14 Write character Teletypewriter style
X;*
X;* Also includes subroutines to:
X;* get_address convert page/row/col to display address
X;* do_char write a character to an address on display
X;* do_attrib change a display address to some attribute
X;* full_screen_scroll used by Fn 14, when it needs to scroll
X;* flash momentarily flash to reverse video and back
X;*
X;********************************************************************
X;
XINCLUDE hercbios.h
X
X;-----------------------------------------------
Xextrn exit_herc_bios:near
Xpublic writechar,scroll_up,scroll_down,tty
Xpublic scr_start,scr_length,num_rows
X;------------------------------------
Xcseg segment public
X assume cs:cseg,ds:bios_data
X;
X
X;**************************************************************
X;*
X;* FUNCTION 6 & 7 - SCROLL UP & DOWN
X;* (Placeholder only - not yet implemented)
X;*
X;* AL = Number of rows to scroll (if 0, blank scroll area)
X;* BH = Fill attribute (we ignore, since writechar destroys old attrib)
X;* CX = Upper left corner (CH=row, CL=col)
X;* DX = Lower right corner (DH=row, DL=col)
X;*
X;****************************************************************
X;
Xscroll_up:
Xscroll_down:
X;
X jmp exit_herc_bios
Xpage
X;********************************************************************
X;*
X;* FUNCTION 9 & 10 - WRITE A CHARACTER AT CURRENT CURSOR
X;*
X;* AL = character code to be written
X;* AH = 9 (write char with attribute) or 10 (write char normal)
X;* BL = new attribute (limited selection in graphics mode)
X;* BH = display page number
X;* CX = count of how many characters to write
X;*
X;********************************************************************
X;
Xwritechar:
X; ; Get the address corresponding to cursor[page]
X push bx
X mov bl,bh ; page to BX
X xor bh,bh
X shl bx,1 ; *2 for word pointer
X mov dx,curs_pos[bx] ; appropriate cursor position to DX
X pop bx
X call get_address ; get display address in DI
X;
Xwrchar_loop:
X; ; Write a character to that address
X call do_char ; arguments set up already
X;
X; ; If function 9, modify the character's attributes
X cmp ah,9 ; Function 9?
X jne no_attrib ; no, don't do attributes
X call do_attrib ; yes, and arguments already set up
Xno_attrib:
X;
X inc di ; move to next position, without moving
X ; the official cursor
X loop wrchar_loop ; continue until CX count exhausted
X jmp exit_herc_bios
Xpage
X;*****************************************************************
X;*
X;* FUNCTION 14 - TELETYPEWRITER-STYLE CHARACTER WRITE
X;*
X;* AL = Character to be written
X;*
X;******************************************************************
X;
Xtty:
X assume ds:bios_data
X mov bl,active_page ; active page to BX
X xor bh,bh
X mov dx,curs_pos[bx] ; get cursor for active page
X push bx
X mov bh,bl ; move page to BH
X call get_address ; address of character to DI
X pop bx
X;
X; ; process the character
X; ; check if CR
X cmp al,13 ; carriage return?
X jne not_cr
X mov dl,0 ; go to first column
X jmp fix_curs
X; ; check if LF
Xnot_cr: cmp al,10 ; line feed?
X jne not_lf
X inc dh ; next line
X jmp fix_curs
X; ; check if BS
Xnot_lf: cmp al,8 ; backspace?
X jne not_bs
X cmp dl,0 ; already first column?
X je fix_curs ; yup. do nothing
X dec dl ; nope. move cursor left one
X dec di ; also move address pointer left one
X mov al,32 ; set character to space
X call do_char ; and write the space, but don't move
X jmp fix_curs
X; ; check if BEL
Xnot_bs: cmp al,7 ; bell character?
X jne not_bl
X pop es ; restore registers
X pop di
X pop si
X pop dx
X pop cx
X pop bx
X pop ds
X jmp vid_bios ; ... and use the normal BIOS to ring the bell
X; call flash ; can't do BEL standard. Blink display instead
X; jmp fix_curs
X; ; ordinary printing character, so display it
Xnot_bl: call do_char ; write it to screen
X inc dl ; cursor one to the right
X;
X; ; now look at the cursor, do what's necessary to
X; ; fix it up, and save it away.
Xfix_curs:
X cmp dl,89 ; beyond last column?
X jle chk_scroll ; not yet
X xor dl,dl ; yes. do a CR
X inc dh ; ... and a LF
Xchk_scroll:
X cmp dh,cs:num_rows ; now see if we're beyond last row?
X jl exit_tty ; not yet
X call full_screen_scroll
X ; yes. Scroll the screen up one
X dec dh ; ... and scroll cursor, too.
X jmp chk_scroll
X;
Xexit_tty:
X mov curs_pos[bx],dx ; save cursor position
X jmp exit_herc_bios
Xpage
X;--------------------------------------------------------------------
X;
X; GET_ADDRESS SUBROUTINE
X;
X; BH = display page
X; DX = cursor position (DH=row, DL=col)
X;
X; returns:
X; DI = displacement of top row of pixels
X;
X;--------------------------------------------------------------------
X;
Xget_address:
X push cx ; save it
X
X; ; compute display address from cursor_pos
X mov cl,dh ; get row # in cx
X xor ch,ch
X shl cx,1 ; begin fast multiply by 90 (1011010 B)
X mov di,cx
X shl cx,1
X shl cx,1
X add di,cx
X shl cx,1
X add di,cx
X shl cx,1
X shl cx,1
X add di,cx ; end fast multiply by 90
X mov cx,di ; copy answer back to cx
X shl di,1 ; *2 for ibm graphics mode
X cmp video_mode,herc_mode
X jne ibm_ad ; not herc mode
X add di,cx ; *3 for herc mode
Xibm_ad: xor ch,ch ; columns in CX
X mov cl,dl
X add di,cx ; add in col. address in DI
X cmp bh,0 ; if page 1, set high-order bit of address
X je pg0
X or di,8000H
Xpg0:
X; ; address now in DI
X;
X pop cx ; restore it
X ret
Xpage
X;--------------------------------------------------------------------
X;
X; DO_CHAR SUBROUTINE
X;
X; AL = character to write
X; DI = diplacement (address) of top row of pixels
X;
X; Note: SI and ES are destroyed
X;
X;--------------------------------------------------------------------
X;
Xdo_char:
X push ax
X push bx
X push cx
X push di
X push ds
X;
X; ; get scan pattern table pointer into BX
X cmp video_mode,herc_mode
X je herc_1
X mov bx,offset ibm_pattern
X ; IBM graphics mode - use appropriate table
X jmp c_1
Xherc_1: mov bx,offset herc_pattern
X ; herc graphics mode - use appropriate table
Xc_1:
X;
X; ; set up source address registers
X xor ah,ah ; character to SI
X mov si,ax
XIFDEF iAPX286
X shl si,3 ; *8 for 8-byte table entry
XELSE
X shl si,1 ; *8 for 8-byte table entry
X shl si,1
X shl si,1
XENDIF
X ; next, find beginning of table
X cmp al,7Fh ; ROM or user table?
X jg u_tbl
X ; ROM table
X add si,charbase ; character table base added to offset
X mov ax,mpx_bios ; BIOS code segment to DS
X mov ds,ax
X jmp c_2
Xu_tbl: ; user table
X xor ax,ax ; zero (interrupt vector) to DS
X mov ds,ax
X mov ax,si ; save table offset in AX
X assume ds:intvec
X lds si,user_table ; load DS:SI from interrupt vector
X add si,ax ; add offset into table base
Xc_2:
X;
X; ; set up destination address registers
X mov ax,pixbase ; get display segment in ES
X mov es,ax
X ; displacement already in DI
X;
X;
X; ; transfer the character
X mov ax,di ; save top-row displacement in AX
X mov cx,8 ; transfer 8 rows
X cld ; direction = up
Xc_loop: mov di,ax ; top-row displacement
X add di,cs:[bx] ; add entry from scan-pattern table
X movsb ; actually transfer a byte and bump SI & DI
X add bx,2 ; next entry in scan-pattern table
X loop c_loop
X;
X; ; if hercules mode, blank the extra rows
X pop ds ; restore DS to Bios data
X assume ds:bios_data
X cmp video_mode,herc_mode
X jne c_3
X ; Hercules mode
X mov si,ax ; don't need SI. Save top-row displacement
X xor ax,ax ; zero AX
X mov cx,4 ; four rows to blank
X cld
Xc_blnk: mov di,si ; top-row displacement
X add di,cs:[bx] ; add entry from scan-pattern table
X stosb ; transfer a zero byte
X add bx,2 ; next entry in scan-pattern table
X loop c_blnk
Xc_3:
X;
X; ; clean up and return
X pop di
X pop cx
X pop bx
X pop ax
X ret
Xpage
X;---------------------------------------------------------------------
X;
X; DO_ATTRIB SUBROUTINE
X;
X; BL = attribute byte
X; DI = displacement (address) of top row of pixels
X; ES is destroyed
X;
X; Because attributes don't "just happen" in graphics mode, here's
X; what we have to transform them to.
X;
X; CODE USUALLY MEANS IBM MODE HERC MODE
X; 00 invisible invisible invisible
X; 01 underline [normal] underline
X; 07 normal normal normal
X; 0F hi-intens [rev video] [rev video]
X; 70 rev video rev video rev video
X;
X; Anything else displays as normal
X; Note that there's no way to make blinking happen.
X;
X;-----------------------------------------------------------------------
X;
Xdo_attrib:
X assume ds:bios_data
X push ax
X mov ax,pixbase ; Display base to ES
X mov es,ax
X pop ax
X;
X; ; which attribute, if any?
X and bl,7Fh ; mask off blink bit
X cmp bl,0 ; invisible?
X je invisible
X cmp bl,0Fh ; reverse video? (instead of bright)
X je reverse
X cmp bl,70H ; reverse video?
X je reverse
X cmp bl,01 ; underline?
X je underline
X ret ; none of the above. Display normal.
X;
X; ; underline the character
Xunderline:
X cmp video_mode,herc_mode
X je ul_1
X ret ; don't do it for IBM mode
Xul_1: mov byte ptr es:[di+40B4h],0FFh
X ; move ones to 11th line of pixel array
X ; 40B4h is the 11th entry in herc_pattern
X ret
X;
X; ; make it invisible
Xinvisible:
X push ax
X push bx
X push cx
X push dx
X xor ax,ax ; zero the AX
X cmp video_mode,herc_mode
X je herc_3
X mov bx,offset ibm_pattern
X ; point to scan pattern
X jmp inv_1
Xherc_3: mov bx,offset herc_pattern
X ; point to scan pattern
Xinv_1: mov dx,di ; save addr of top row of pixels in DX
X mov cx,8 ; 8 bytes to be moved
X cld ; direction = up
Xinvis_loop:
X mov di,dx ; top row address
X add di,cs:[bx] ; add scan-table offset
X stosb ; move a zero byte
X add bx,2 ; bump the scan-table pointer
X loop invis_loop
X pop dx
X pop cx
X pop bx
X pop ax
X ret
X;
X; ; reverse video
Xreverse:
X push bx
X push cx
X push dx
X cmp video_mode,herc_mode
X je herc_4
X mov bx,offset ibm_pattern
X ; point to scan pattern
X mov cx,8 ; 8 scan lines for IBM mode
X jmp rev_1
Xherc_4: mov bx,offset herc_pattern
X ; point to scan pattern
X mov cx,12 ; 12 scan lines for Hercules mode
Xrev_1: mov dx,di ; save addr of top row of pixels in DX
X cld ; direction = up
Xrev_loop:
X mov di,dx ; top row address
X add di,cs:[bx] ; add scan-table offset
X not es:byte ptr[di] ; invert one scan line
X add bx,2 ; bump the scan-table pointer
X loop rev_loop
X pop dx
X pop cx
X pop bx
X ret
Xpage
X;--------------------------------------------------------------
X;
X; SUBROUTINE FULL_SCREEN_SCROLL
X;
X; This scrolls the entire screen up one print line (8 or 12 pixels).
X; Actually, we'll protect one line on the bottom (e.g.-function keys).
X;
X;-----------------------------------------------------------------
X;
X; ; A few constants, initialized by set_mode
Xnum_rows db ? ; number of rows in display
X ; = 42 (IBM) or 28 (Herc)
Xscr_start dw ? ; 2*90 or 3*90 depending on mode
Xscr_length dw ? ; number of words to transfer in a sweep
X ; = 41*start /2 = 3690 (IBM)
X ; = 27*start /2 = 3645 (Herc)
X;
Xfull_screen_scroll:
X assume ds:bios_data
X push ds
X push ax
X push cx
X mov ax,pixbase ; start getting display segment
X cmp active_page,0 ; page 0?
X je scr_pg0
X add ax,800H ; page 1. bump by half of 64K
Xscr_pg0:
X mov ds,ax ; save display segment in DS
X mov es,ax ; ... and in ES
X;
X xor ax,ax ; zero AX
X call scr_shift
X mov ax,2000H ; bump interlace counter
X call scr_shift
X mov ax,4000H
X call scr_shift
X mov ax,6000H
X call scr_shift
X;
X pop cx
X pop ax
X pop ds
X ret
X;
X;
X; scr_shift does the actual work of scrolling, one set of interlace
X; lines at a time.
X;
Xscr_shift:
X cld ; block moves will be UP
X mov di,ax ; interlace scan ID to DI
X mov si,ax ; ... and to SI
X add si,cs:scr_start
X ; but bump by "start"
X mov cx,cs:scr_length
X ; set counter for transfer
X rep movsw ; and scroll a set of lines
X xor ax,ax ; set up a zero word
X mov cx,cs:scr_start ; set counter for one more line
X shr cx,1 ; /2 for word transfers
X rep stosw ; and blank the line
X ret
Xpage
X;-----------------------------------------------------------
X;
X; SUBROUTINE FLASH
X;
X; Flashes the screen inverse video and back to normal.
X; Used in place of an audible bell.
X;
X;-------------------------------------------------------------
X;
Xflash:
X push cx
X push di
X push es
X;
X mov di,pixbase ; get display area base
X cmp active_page,0 ; page 0?
X je pg0_f
X add di,800H ; no, page 1
Xpg0_f: mov es,di ; put resulting pointer to display in ES
X;
X; ; loop to invert screen
X xor di,di ; point to beginning of display area
X mov cx,4000H ; number of words to invert
Xflash_loop_1:
X not word ptr es:[di]
X ; invert one location
X add di,2 ; bump location pointer a word
X loop flash_loop_1
X;
X; ; and invert it back to normal
X xor di,di ; point to beginning of display area
X mov cx,4000H ; number of words to invert
Xflash_loop_2:
X not word ptr es:[di]
X ; invert one location
X add di,2 ; bump location pointer a word
X loop flash_loop_2
X;
X pop es
X pop di
X pop cx
X ret
Xpage
X;*****************************************************
X;* Data areas for character handling
X;*****************************************************
X;
Xpixels db 12 dup(?) ; 12 bytes for pixel pattern
Xibm_pattern dw 0000h,2000h,4000h,6000h,005Ah,205Ah,405Ah,605Ah
Xherc_pattern dw 4000h,6000h,005Ah,205Ah,405Ah,605Ah,00B4h,20B4h
Xblank_pattern dw 0000h,2000h,40B4h,60B4h
X;
X;
Xcseg ends
X end
SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > graph.asm
X;*******************************************************
X;*
X;* SET OF GRAPHICS ROUTINES FOR HERCULES BIOS
X;*
X;* Dave Tutelman - 8/86
X;*
X;*-------------------------------------------------------
X;*
X;* do_pixel: draws, erases, or reads a pixel, given an
X;* offset and mask.
X;*
X;**********************************************************
X;
XINCLUDE hercbios.h
X
X;------------------------------------------
Xpublic wr_pixel,end_herc
Xextrn exit_herc_bios:near
X;-----------------------------------------
X;
Xcseg segment public
X assume cs:cseg,ds:bios_data
X;
X;
X;**********************************************
X;*
X;* read or write a pixel:
X;* DX = row # ( y )
X;* CX = col # ( x )
X;* AH = 12 for write, 13 for read
X;* AL = value (0,1, if bit 7=1 EXOR the value)
X;*
X;**********************************************
X;
Xwr_pixel:
X mov bh,video_mode ; check for valid mode
X cmp bh,herc_mode
X je do_pixel
X cmp bh,ibm_mode
X je do_pixel
X jmp exit_herc_bios ; invalid mode. don't do it.
X;
Xdo_pixel:
X push ax ; save function and pixel value
X;
X; ; first compute the address of byte to be modified
X; ; = 90*[row/4] + [col/8] + 2^D*[row/4] + 2^F*page
X mov bh,cl ; col (low order) in BH
X mov bl,dl ; row (low order) in BL
X and bx,0703H ; mask the col & row remainders
XIFDEF iAPX286
X shr cx,3 ; col / 8
X shr dx,2 ; row / 4
X mov al,90
X mul dx ; AX = 90*[ row/4 ]
X add ax,cx ; ... + col/8
X shl bl,5 ; align row remainder
XELSE ; same as above, obscure but fast for 8086
X shr cx,1 ; divide col by 8
X shr cx,1
X shr cx,1
X shr dx,1 ; divide row by 4
X shr dx,1
X shl dx,1 ; begin fast multiply by 90 (1011010 B)
X mov ax,dx
X shl dx,1
X shl dx,1
X add ax,dx
X shl dx,1
X add ax,dx
X shl dx,1
X shl dx,1
X add ax,dx ; end fast multiply by 90
X add ax,cx ; add on the col/8
X shl bl,1 ; align row remainder
X shl bl,1
X shl bl,1
X shl bl,1
X shl bl,1
XENDIF
X add ah,bl ; use aligned row remainder
X cmp active_page,0 ; page 0 active?
X je end_adr_calc ; yup
X or ah,80H ; page 1 active. Set MSB of address
Xend_adr_calc: ; address of byte is now in AX
X;
X mov dx,pixbase ; base of pixel display to DX
X mov es,dx ; ...and thence to segment reg
X mov si,ax ; address of byte w/ pixel to index reg
X mov cl,bh ; bit addr in byte
X mov al,80H ; '1000 0000' in AL
X shr al,cl ; shift mask to line up with bit to read/write
X mov bl,al
X;
X pop bx ; now retrieve original AX into BX
X ; function=BH, pixel value=BL
X cmp bh,13 ; what to do with the pixel?
X je read_pix ; read the pixel.
X cmp bl,0 ; write the pixel. But how?
X je clr_pix ; clear the pixel
X jl exor_pix ; exclusive-or the pixel
X;
Xset_pix: ; set the pixel
X or es:[si],al ; or the mask with the right byte
X jmp exit_herc_bios
X;
Xclr_pix: ;clear the pixel
X not al ; invert the mask, so zero on bit to be cleared
X and es:[si],al ; and the mask with the right byte
X jmp exit_herc_bios
X;
Xexor_pix: ; exclusive-or the pixel
X mov ah,07fH ; mask to rid 7th bit
X and ah,bl ; pixval w/o XOR flag
X jnz do_exor ; ExOr with a 1?
X jmp exit_herc_bios ; no! XOR (0,x) = x. just return.
Xdo_exor:
X xor es:[si],al ; EXOR the pixel with the mask.
X jmp exit_herc_bios
X;
Xread_pix: ; read the pixel
X and al,es:[si] ; read the bit into AL
X jz rd_zro
X mov al,1 ; if it ain't zero, it's one
Xrd_zro: jmp exit_herc_bios
X;
X;
Xend_herc: ; label for end of package. Used by hercbios
X ; to install it.
X;
Xcseg ends
X end
SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > hcharset.asm
X;**************************************************************
X;*
X;* Tests Hercules BIOS, specifically the functions 9 & 10
X;* to put characters on the screen in graphics mode.
X;*
X;***************************************************************
XVIDI equ 10H ; video interrupt, 10H (50H for debug)
Xcseg segment common
X assume cs:cseg,ds:cseg
XSTART proc
X; ; prompt for IBM or Hercules graphics mode
X mov ah,9 ; DOS 9 = display string
X mov dx,offset mode_prmt+100H
X ; display mode prompt
X int 21H ; DOS function
X mov ah,1 ; DOS 1 = kbd input
X int 21H
X mov bl,al ; input char --> BL
X mov ax,6 ; ibm graphics mode
X cmp bl,"h" ; input "h" for Hercules
X jne i_mode
X add ax,2 ; hercules mode
Xi_mode: int VIDI
X;
X xor bh,bh ; page 0
X mov bl,7 ; normal attribute
X mov dh,1 ; cursor at <1,1> to start
X mov dl,1
X;
X mov cx,24 ; do 24 rows
Xrow: push cx ; save row counter
X inc dh ; next row
X mov dl,0 ; back to first column
X mov ah,2 ; cursor move function
X int VIDI
X; ; compute video mode
X mov bl,dh ; row # to BL
X xor bh,bh
X shr bl,1 ; 4 rows per mode
X shr bl,1
X mov bl,mode_seq[bx+100H] ; index into mode sequence for mode
X;
X; ; for debug, first print [row+64]
X mov al,dh
X add al,64
X mov ah,10 ; fn 10 prints w/o attributes
X mov cx,1
X int VIDI
X;
X xor bh,bh ; page 0
X mov cx,64 ; each row 64 characters
Xachar: push cx ; save char counter
X mov ah,9 ; write_char function
X mov al,dh ; character = col + (row mod 2)*64
X and al,1 ; row mod 2
X ror al,1 ; *128
X shr al,1
X add al,dl ; + col
X mov cx,1 ; write one of them
X int VIDI
X inc dl ; increment row counter
X mov ah,2 ; cursor move function
X int VIDI
X pop cx ; restore character counter
X loop achar
X pop cx ; restore row counter
X loop row
X;
X; ; draw a line where it should start
X mov dx,5 ; row 5
X mov cx,0 ; col 0
Xline: push cx
X push dx
X mov ax,0C01H ; function 12=pixel
X int VIDI
X pop dx
X pop cx
X inc cx ; step col
X cmp cx,700 ; ...until 700
X jle line
X;
X; ; wait for a keystroke
X mov ah,1
X int 21H
X;
X mov ax,7 ; back to alpha mode
X int VIDI
X;
X; ; Now return to system
X xor ax,ax ; zero --> AX
X int 21H ; DOS function call 0 - terminate normally
X;
Xmode_prmt db "hercules or ibm mode? [ibm] $"
Xmode_seq db 7,0Fh,1,70h,0,9 ; sequence norm,hi,ul,rev,invis,norm
XSTART endp
Xcseg ends
X end START
SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > hercbios.asm
X;*******************************************************
X;*
X;* Main program file for HERCBIOS
X;*
X;* Dave Tutelman - 8/86
X;*
X;*------------------------------------------------------
X;*
X;* INT10 -- acts as pre-handler for video interrupts
X;* (BIOS calls) for Hercules & SuperComputer
X;* monochrome graphics board. Calls real BIOS
X;* if not a Hercules special. Handled here are:
X;*
X;* Fn 0 Set mode (only 6 & 8)
X;* and all functions, when in mode 6 or 8.
X;* Actually, we've only implemented:
X;* Fn 2 Set cursor position
X;* Fn 3 Read cursor position
X;* Fn 5 New display page
X;* Fn 9 Write character with attribute
X;* Fn 10 Write character
X;* Fn 12 Write pixel
X;* Fn 13 Read pixel
X;* Fn 14 Teletypewriter-style character write
X;* Fn 15 Get video status
X;*
X;* The only allowable modes for these boards are:
X;* 6 IBM graphics (we handle it, but poor aspect ratio).
X;* 7 Monochrome (with 2 pages)
X;* 8 Hercules graphics mode.
X;*
X;**********************************************************
X;
XINCLUDE hercbios.h
X
Xextrn writechar:near,tty:near,scroll_up:near,scroll_down:near
Xextrn scr_start:word,scr_length:word,num_rows:byte
Xextrn wr_pixel:near
Xextrn end_herc:near
Xpublic exit_herc_bios,int10,vid_vector
Xpublic set_mode,set_curs,read_curs,new_page,status
X;-----------------------------------------
Xpage
X;************************************************************
X;*
X;* Install the Hercules video handler
X;*
X;************************************************************
Xcseg segment public
X assume cs:cseg,ds:cseg
X
X ORG 100h
X;
XSTART:
X;
X push ax
X push es
X push ds
X;
X xor ax,ax ; zero the acc
X mov es,ax ; ES points to zero (interrupt vector)
X ; Get ROM BIOS video entry point, and save in "rom_bios"
X mov ax,es:[4*VIDI]
X mov word ptr cs:rom_bios,ax
X mov ax,es:[4*VIDI+2]
X mov word ptr cs:rom_bios+2,ax
X ; Now plant the HERCBIOS entry point in interrupt vector
X mov ax,offset int10 ; address of video handler to AX
X mov es:[4*VIDI],ax ; and store it in interrupt vector 10H
X mov ax,cs ; same for the segment of video handler
X mov es:[4*VIDI+2],ax ; ...
X;
X; Leave the message that we're installed
X mov ax,cs ; DS:DX pointing to message
X mov ds,ax
X mov dx,offset install_msg
X mov ah,9 ; display-string function
X int 21h
X
X pop ds
X pop es
X pop ax
X;
X mov dx,offset end_herc ; set dx to end of this program
X int 27H ; terminate, but stay resident
X;
Xinstall_msg db "BIOS for Hercules-compatible Graphics - "
X db "(DMT Aug 1986)",10,13,'$'
Xpage
X;************************************************************
X;*
X;* Beginning of video interrupt handler
X;*
X;************************************************************
X;
X;
Xint10 proc far
X;
X sti ; allow further interrupts
X push ds ; save DS
X push ax ; save AX
X mov ax,bios_data ; bios data segment --> AX
X mov ds,ax ; now put bios data segment in DS
X assume ds:bios_data ; and tell assembler about it
X; ; check current mode
X mov ah,video_mode ; get current mode
X cmp ah,herc_mode ; test for a graphics mode
X je herc_bios
X cmp ah,ibm_mode
X je herc_bios
X; ; setmode to a graphics mode?
X pop ax ; restore AX
X push ax ; ...but leave it on stack
X cmp ax,0006 ; Fn = set to IBM hi-res mode?
X je herc_bios
X cmp ax,0008 ; Fn = set to Herc graphics mode?
X je herc_bios
X;
Xnorm_bios: ; if we get here, just go to real BIOS
X pop ax ; restore stack to pre-interrupt state
X pop ds
X db 0EAh ; opcode for FAR JUMP to rom_bios
Xrom_bios dd ? ; normal video bios address (in ROM)
X;
Xherc_bios: ; jump table for special Hercules BIOS
X;
X pop ax ; restore ax
X push bx ; save regs
X push cx
X push dx
X push si
X push di
X push es
X;
X push ax
X mov al,ah ; function # to AX
X xor ah,ah
X shl ax,1 ; *2 for word vector
X mov si,ax ; put in SI to index into vector
X pop ax ; restore old AX
X cmp si,offset vid_vec_end-offset vid_vector
X ; function number within range?
X jge exit_herc_bios ; function number out of range
X add si,offset vid_vector
X jmp word ptr cs:[si]
X ; jump to routine via vector
X;
X
Xvid_vector: ; jump vector for hercules video routines
X dw offset set_mode ; 0 = set mode
X dw offset exit_herc_bios ; 1 = cursor type (NA)
X dw offset set_curs ; 2 = set cursor position
X dw offset read_curs ; 3 = read cursor position
X dw offset exit_herc_bios ; 4 = light pen (NA)
X dw offset new_page ; 5 = choose active page
X dw offset scroll_up ; 6 = scroll up
X dw offset scroll_down ; 7 = scroll down
X dw offset exit_herc_bios ; 8 = read character (NA)
X dw offset writechar ; 9 = write char & attribute
X dw offset writechar ;10 = write character
X dw offset exit_herc_bios ;11 = set color palette (NA)
X dw offset wr_pixel ;12 = write pixel
X dw offset wr_pixel ;13 = read pixel
X dw offset tty ;14 = teletype write
X dw offset status ;15 = return video state
Xvid_vec_end:
X;
Xexit_herc_bios:
X pop es ; restore regs
X pop di
X pop si
X pop dx
X pop cx
X pop bx
X pop ds
X iret ; and return
Xpage
X;********************************************************************
X;*
X;* FUNCTION 0 - SET VIDEO MODE
X;*
X;* Only gets here to set a hi-res graphics mode
X;* 6=IBM
X;* 8=Hercules
X;* [ AX destroyed ]
X;*
X;*******************************************************************
X;
Xset_mode:
X; ; is it a graphics mode?
X cmp al,herc_mode ; set to hercules mode?
X je g_mode
X cmp al,ibm_mode ; set to IBM mode?
X je g_mode
X ; Neither. Leave it to normal BIOS
X pop es ; restore regs
X pop di
X pop si
X pop dx
X pop cx
X pop bx
X pop ds
X jmp vid_bios ; and go to MPX-16 BIOS
X;
Xg_mode: mov video_mode,al ; save video mode in BIOS data area
X mov active_page,ah ; zero the active page in BIOS data
X mov n_cols,90 ; 90 character columns in graphics mode
X;
X;* clear display area
X mov ax,pixbase ; get starting address
X mov es,ax ; page base to ES
X mov cx,8000H ; word counter
X mov di,0 ; start at beginning of display
X cld ; direction "up"
X xor ax,ax ; zero AX
X rep stosw ; write zero to both pages
X;
X;* load the 6845 internal registers
X;
X; ; first set up the loop
X push ds ; save DS
X mov ax,cs ; get cseg into DS
X mov ds,ax
X assume ds:cseg
X mov dx,vid_port ; 6845 index port address to DX
X mov si,offset vid_parm_table
X ; table pointer to SI
X mov cx,16 ; 16 parameters in table
X xor ax,ax ; zero AX (AH will be index counter)
X; ; now execute the loop
Xinit_6845_loop:
X mov al,ah ; index counter to AL
X out dx,al ; output index to 6845
X inc dx ; point DX to data reg
X mov al,[si] ; get table entry
X out dx,al ; output to 6845 data reg
X dec dx ; point DX back to index reg
X inc ah ; bump index counter
X inc si ; bump table pointer
X loop init_6845_loop
X pop ds ; restore DS
X assume ds:bios_data ; restore DS assumed
X;
X;* now set the 6845 control register
X mov dx,vid_port+4 ; control port address
X mov al,0AH ; graphics control byte
X cmp active_page,0 ; get current page
X je pg0_F0 ; skip if zero
X or al,80H ; page 1 to control byte
Xpg0_F0: out dx,al ; and ship to 6845
X mov chip_ctrl,al ; also save in bios data area
X;
X;* save cursor position (0,0) in bios data area
X xor ax,ax ; zero AX
X mov curs_pos,ax ; write zero to pg.0 cursor postion
X mov curs_pos+2,ax ; write zero to pg.1 cursor postion
X;
X;* initialize scrolling parameters
X;
X cmp video_mode,herc_mode
X je h_parm
X mov cs:scr_start,180 ; IBM parameters
X mov cs:scr_length,3690 ;
X mov cs:num_rows,42 ;
X jmp parm_done
Xh_parm: mov cs:scr_start,270 ; Herc parameters
X mov cs:scr_length,3645 ;
X mov cs:num_rows,28 ;
Xparm_done:
X;
X jmp exit_herc_bios
X;
X;* table of 6845 chip parameters
X;
Xvid_parm_table db 53,45,46,7,91,2,87,87,2,3,62H,3,0,0,0,0
X;vid_parm_table db 54,45,46,8,91,2,87,87,2,3,62H,3,0,0,0,0
X ;DMT's monitor
Xpage
X;********************************************************************
X;*
X;* FUNCTION 2 - SET CURSOR POSITION
X;*
X;* DX = new row (DH) and column (DL)
X;* BH = display page number
X;*
X;********************************************************************
X;
Xset_curs:
X;
X; * save in BIOS data area
X mov bl,bh ; page # to bl
X xor bh,bh ; zero bh (page # = BX)
X shl bx,1 ; times 2 for word
X mov curs_pos[bx],dx ; store in data area
X;
X; * if page # = active page, then we should actually move cursor
X; * However, cursor doesn't show in graphics mode, so we won't.
X;
X jmp exit_herc_bios
X;
Xpage
X;********************************************************************
X;*
X;* FUNCTION 3 - READ CURSOR POSITION
X;*
X;* on entry
X;* BH = display page number
X;*
X;* on exit
X;* CX = cursor type/size
X;* DX = current row (DH) and column (DL)
X;*
X;********************************************************************
X;
Xread_curs:
X; ; uncover the return portion of the stack
X pop es
X pop di
X pop si
X pop dx
X pop cx
X; ; now get the data and push onto stack
X push curs_mode ; cursor type to CX position in stack
X mov bl,bh ; page # to BX
X xor bh,bh
X shl bx,1 ; *2 for word offset
X push curs_pos[bx] ; cursor position for specified page
X ; to DX position in stack
X; ; refill the stack for return
X push si
X push di
X push es
X;
X jmp exit_herc_bios
Xpage
X;********************************************************************
X;*
X;* FUNCTION 5 - SELECT NEW DISPLAY PAGE
X;*
X;* AL = new display page number
X;*
X;********************************************************************
X;
Xnew_page:
X cmp al,2 ; page < 2?
X jl f5_1 ; yup
X jmp exit_herc_bios ; nope. can't do it.
X;
Xf5_1: mov active_page,al ; put away active page in bios data
X; * put starting address in 6845 register 12
X mov ah,al ; save page number in AH
X mov dx,vid_port ; index pointer address
X mov al,12 ; save in register 12
X out dx,al ; and set index pointer to 12
X mov al,ah ; restore page to AL
X ror al,1 ; page to high-order bit
X shr al,1 ; two bytes per word
X inc dx
X out dx,al ; ...and output it to register
X; * put control byte in 6845 port
X mov al,ah ; get back page number
X ror al,1 ; page to high-order bit
X or al,0AH ; create chip control byte
X mov chip_ctrl,al ; save it in data area
X mov dx,vid_port+4 ; control port address
X out dx,al ; send control byte to chip
X;
X jmp exit_herc_bios
Xpage
X;***********************************************************************
X;*
X;* FUNCTION 15 - RETURN VIDEO STATUS
X;*
X;* On exit:
X;* AL = current video mode
X;* AH = number of active display columns
X;* BH = current active page number
X;*
X;***********************************************************************
X;
Xstatus:
X; ; first uncover the stack
X pop es
X pop di
X pop si
X pop dx
X pop cx
X pop bx
X; ; now get the parameters needed
X mov al,video_mode
X mov ah,90 ; all our graphics modes have 90 cols
X mov bh,active_page
X; ; and push back onto the stack for return
X push bx
X push cx
X push dx
X push si
X push di
X push es
X;
X jmp exit_herc_bios
X;
Xint10 endp
X;
Xcseg ends
X end START
SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > hercbios.aut
X
X================================================================================
X
XNewsgroups: net.sources
XPath: decwrl!pyramid!hplabs!hao!nbires!seismo!caip!clyde!cbatt!cbosgd!ihnp4!drutx!mtuxo!mtuxt!dmt
XSubject: Hercules graphics BIOS
XPosted: 28 Aug 86 02:47:07 GMT
XOrganization: AT&T Information Systems, Holmdel NJ
X
X
XWell, here's the promised Hercules driverfor the PC. It's in SHAR format,
Xand the instructions for assembly and use are in "hercbios.doc".
XEnjoy!
X---------------------------------------------------------------
X ---=== Dave Tutelman
X -------===== Physical - AT&T Information Systems
X ----------====== Room 1H120
X ==--------======== Juniper Plaza, Route 9
X ====---========= Freehold, NJ 07728
X ============ Logical - ...ihnp4!mtuxo!mtuxt!dmt
X ====== Audible - (201)-577-4232
X---------------------------------------------------------------SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > hercbios.h
X.XLIST
X page 66,132
X;************************************************************
X;
X; Header file for inclusion in HERCBIOS assemblies
X;
X; Dave Tutelman - 8/86
X;
X;*************************************************************
X
X;iAPX286 equ 1 ; UN-COMMENT FOR A 186 or 286 MACHINE!
X ; Some of the "ugly" constructs are for speed
X ; on the 808X, while the "obvious" constructs
X ; run faster on the 186 & 286.
XVIDI equ 10H ; video interrupt, 10H for real, 50H for debug
Xpixbase equ 0B000H ; beginning segment of graphics board
Xmpx_bios equ 0F000H ; MPX-16 BIOS segment address
Xvid_offset equ 0F065H ; MPX-16 video offset in BIOS
Xcharbase equ 0FA6EH ; MPX-16 BIOS character table offset
Xherc_mode equ 8 ; Hercules graphics mode
Xibm_mode equ 6 ; IBM Hi-Res color graphics mode.
X ; we'll try to handle it.
Xvid_port equ 03B4H ; 6845 index register (data reg = 3B5H )
X ; (control port = 3B8H )
X;------------------------------------------
Xbios segment at mpx_bios ; setup call to vid_bios
X org vid_offset
Xvid_bios proc far
Xvid_bios endp
Xbios ends
X;------------------------------------------------
Xbios_data segment at 040h
X org 049h
Xvideo_mode db ? ; current video mode
Xn_cols dw ? ; number of columns in video display
X org 050h
Xcurs_pos dw 8 dup(?) ; cursor for each of 8 pages
Xcurs_mode dw ? ; cursor mode
Xactive_page db ? ; current active display page
Xvideo_base dw ? ; video port base
Xchip_ctrl db ? ; current setting of 3X8 register
Xbios_data ends
X;------------------------------------
Xintvec segment at 0 ; interrupt vector
X org 4*1Fh ; interrupt 1FH
Xuser_table dd ?
Xintvec ends
X;------------------------------------
X
XIFDEF iAPX286
X .286c ; allow 286/186-only instructions
XENDIF
X
X.LIST
SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > hercdemo.asm
X page ,132
X title hercdemo - quick and dirty herc demo
X;
X; Hercdemo - (c) 1986 by Reid Brown, P.O. Box 1023, Issaquah, WA. 98027
X;
X; This is a quick and dirty program to show off the Hercules
X; board. I place if freely into the public domain so others
X; can diddle their Herc boards as well, so long as it is not
X; used for any commercial purposes.
X;
X
Xmessage macro row,col,string
X mov cx,row
X mov bx,col
X mov si,offset string
X call print
X endm
X
Xhdraw macro row,col,len
X mov cx,row
X mov bx,col
X mov dx,len
X call hline
X endm
X
Xvdraw macro row,col,len
X mov cx,row
X mov bx,col
X mov dx,len
X call vline
X endm
X
Xcode segment
X assume cs:code, ds:code, es:code, ss:code
X org 100h
Xstart: jmp begin
X
XIBMROM equ 0F000h
XCHARTAB equ 0FA6Eh
XHERCSEG equ 0B800h
X
XMODEPORT equ 3B8h
X
XSTRING0 db 'HERCULES DEMO',0
XSTRING1 db 'A funny thing happened on the way to the forum.',0
XSTRING2 db 'You, too, can have a rewarding career in computers...',0
XSTRING3 db 'Strike any key to proceed...',0
X
X
XCON8 db 8
XCON180 db 180
X
Xbegin proc near
X mov dx, MODEPORT ; select herc mode port
X mov al, 08Ah
X out dx, al ; graphics mode, video on, page 1
X
X call graphics ; set 6845 for graphics
X call clear ; clear screen RAM
X
X vdraw 10,5,20 ; draw a vertical
X vdraw 10,65,20 ; - hopefully, a box!
X hdraw 10,6,60 ; draw a line
X hdraw 30,6,60 ; and another
X
X message 12,29,STRING0 ; 1st message
X message 17,10,STRING1 ; 2nd message
X message 23,10,STRING2 ; 3nd message
X message 29,20,STRING3 ; ...
X
X;
X; done - clean up and reset
X;
X mov ax, 0C07h ; flush buffer, read char
X int 21h ; wait for any input
X
X call text ; reset 6845
X
X mov dx, MODEPORT ; select herc mode port
X mov al, 00001000B ; re-enable mono
X out dx, al
X
X mov ax, 4C00h
X int 21h ; exit
Xbegin endp
X
X;
X; print - print text in graphics mode
X;
X; cx = row
X; bx = column
X; si = address of string (null terminated) to print
X;
Xprint proc near
X
Xloop: lodsb ; get next char
X or al, al ; end of display?
X je pdone
X call display
X inc bx ; bump to next column
X jmp loop
Xpdone: ret
X
Xprint endp
X
X;
X; display - output an 8x8 character from the IBM ROM to the Herc board
X;
X; AX = char, BX = column (0-89), CX = row(0-42) ** all preserved **
X;
Xdisplay proc near
X push ds ; save the lot
X push es
X push ax
X push bx
X push cx
X push dx
X push si
X push di
X
X; setup ds -> IBM ROM, and si -> index into IBM ROM character table located
X; at 0fa6eh in the ROM
X
X and ax, 07fh
X mul CS:CON8 ; mult by 8 bytes of table per char
X mov si, ax
X mov ax, IBMROM
X mov ds, ax
X assume ds:nothing
X add si, CHARTAB ; add offset of character table
X
X; compute index into Hercules screen memory for scan line 0. The remaining
X; seven scan lines are all at fixed offsets from the first.
X;
X; Since graphics mode treats the screen as sets of 16x4 "characters",
X; we need to map an 8x8 real character onto the front or back of
X; a pair of graphics "characters". The first four scan lines of our
X; 8x8 character will map to the top graphics "character", and the second
X; four scan lines map to the graphics character on the "line" (4 scan
X; lines high) below it.
X;
X; For some exotic hardware reason (probably speed), all scan line 0
X; bits (i.e. every fourth scan line) are stored in memory locations
X; 0-2000h in the screen buffer. All scan line 1 bits are stored
X; 2000h-4000h. Within these banks, they are stored by rows. The first
X; scan line on the screen (scan line 0 of graphics character row 0)
X; is the first 45 words of memory in the screen buffer. The next 45
X; words are the first scan line graphics row 1, and since graphics
X; "characters" are 4 bits high, this second scan line is physically
X; the fifth scan line displayed on the screen.
X;
X; SO, to display an 8x8 character, the 1st and 5th rows of dots are
X; both scan line 0 of the graphics "character", the 2nd and 6th are
X; scan line 1, and so on.
X;
X; The column (0-89) tells which byte in a scan line we need to load.
X; Since it takes two rows of graphics characters to hold one row of
X; our characters, column+90 is a index to scan line 4 rows of pixels
X; higher (n+4). Thus 180 bytes of screen memory in any bank (0h, 2000h,
X; 4000h, 6000h) represent a row of 8x8 characters.
X;
X; The starting location in screen memory for the first scan line of
X; a character to be displayed will be: (row*180)+column
X; The 5th scan line will be at: (row*180)+column+90
X;
X; The second and 6th scan lines will be at the above offsets plus
X; the bank offset of 2000h. The third and 7th, add 4000h and finally
X; the 4th and 8th, add 6000h.
X;
X mov ax, HERCSEG
X mov es, ax ; es = hercules page 0
X mov ax, cx ; get row
X mul CS:CON180 ; mult by 180(10)
X mov di, ax ; di = index reg
X cld ; insure right direction
X
X;output 8 segments of character to video ram
X
X lodsb ; line 0
X mov es:[di+bx], al
X lodsb
X mov es:[di+bx+2000h], al ; line 1
X lodsb
X mov es:[di+bx+4000h], al ; line 2
X lodsb
X mov es:[di+bx+6000h], al ; line 3
X lodsb
X mov es:[di+bx+90], al ; line 4
X lodsb
X mov es:[di+bx+2000h+90], al ; line 5
X lodsb
X mov es:[di+bx+4000h+90], al ; line 6
X lodsb
X mov es:[di+bx+6000h+90], al ; line 7
X
X pop di
X pop si
X pop dx
X pop cx
X pop bx
X pop ax
X pop es
X pop ds
X ret
Xdisplay endp
X
X;
X; clear - clear page 1 of the screen buffer to zero (effectively, blank
X; the screen)
X;
Xclear proc
X push es
X push ax
X push cx
X push di
X
X mov ax, HERCSEG
X mov es, ax
X xor di, di
X mov cx, 4000h
X xor ax, ax
X cld
X
X rep stosw ; zero out screen page
X
X pop di
X pop cx
X pop ax
X pop es
X ret
Xclear endp
X
X;
X; hline - draw a horizontal line at scan line 0 of a specified 8x8 character
X; cell sized row, for a specified no. of characters
X;
X; cx = row
X; bx = col
X; dx = len
X;
Xhline proc near
X push es
X push ax
X push cx
X push di
X
X mov ax,cx ; copy to accum for multiply
X mul cs:CON180 ; mult by 180 to get offset
X mov di,ax ; copy to dest ptr
X add di,bx ; add column offset
X mov cx,dx ; put byte count in count reg
X mov ax, HERCSEG
X mov es, ax
X mov ax, 0ffh ; pattern = all bits ON
X cld
X
X rep stosb ; put bits on screen
X
X pop di
X pop cx
X pop ax
X pop es
X ret
X
Xhline endp
X
X;
X; vline - draw a vertical line in the last bit position of a given char
X; cell, extending downward for a specified no. of chars
X;
X; cx = row
X; bx = col
X; dx = len
X;
Xvline proc near
X push es
X push ax
X push cx
X push di
X
X mov ax,cx ; copy to accum for multiply
X mul cs:CON180 ; mult by 180 to get offset
X mov di,ax ; copy to dest ptr
X mov cx,dx ; put byte count in count reg
X mov ax, HERCSEG
X mov es, ax
X mov ax, 1 ; pattern = last bit on
X
Xvloop: mov es:[di+bx], al
X mov es:[di+bx+2000h], al ; line 1
X mov es:[di+bx+4000h], al ; line 2
X mov es:[di+bx+6000h], al ; line 3
X mov es:[di+bx+90], al ; line 4
X mov es:[di+bx+2000h+90], al ; line 5
X mov es:[di+bx+4000h+90], al ; line 6
X mov es:[di+bx+6000h+90], al ; line 7
X add di,180 ; advance to next line
X loop vloop ; continue for all rows
X
X pop di
X pop cx
X pop ax
X pop es
X ret
X
Xvline endp
X
Xgraphics proc near
X mov si, offset graph_parms
Xg_cont: mov dx, 3b4h ; point to index reg
X mov cx, 16
X xor ax, ax
Xg_loop: mov al, ah
X out dx, al
X inc dx
X mov al, [si]
X out dx, al
X dec dx
X inc ah
X inc si
X loop g_loop
X ret
Xgraph_parms db 35h,2dh,2eh,7,5bh,2,57h,57h,2,3,0,0,0,0,0,0
Xgraphics endp
X
Xtext proc near
X mov si, offset text_parms
X jmp g_cont
Xtext_parms db 61h,50h,52h,0fh,19h,6,19h,19h,2,0dh,0bh,0ch,00,00,00,00
Xtext endp
X
X
Xcode ends
X
X end start
SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > hercmake.att
X
X# Makefile for HERCBIOS.COM
XSRC=hercbios gchar graph
XDEST=a:
X
Xhercbios.com : hercbios.obj gchar.obj graph.obj
X link hercbios gchar graph,,/MAP;
X exe2bin hercbios.exe hercbios.com
X del hercbios.exe
X
Xhercbios.obj : hercbios.asm hercbios.h
Xgchar.obj : gchar.asm hercbios.h
Xgraph.obj : graph.asm hercbios.h
X
X
X# Makes for the demo & test program, using deSmet C
X
Xtestpix.exe : testpix.o hercpixl.o
X bind testpix hercpixl
X
Xtestpix.o : testpix.c
X c88 testpix
X
Xhercpixl.o : hercpixl.c
X c88 hercpixl
X
X# Make a backup or distribution disk
Xbackup :
X for %f in ($(SRC)) do copy %f.asm $(DEST)
X copy hercbios.h $(DEST)
X copy hercbios.com $(DEST)
X copy hercbios.doc $(DEST)
X copy makefile $(DEST)
X
Xdistrib :
X make backup
X copy hercpixl.c $(DEST)
X copy testpix.* $(DEST)
X copy hcharset.* $(DEST)SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > hercmake.lcm
X#
X# Makefile for HERCBIOS.COM
X# (designed for Larry Campbell's version of MAKE)
X#
X
Xhercbios.com : hercbios.obj gchar.obj graph.obj
X link hercbios gchar graph,,/MAP;
X exe2bin hercbios.exe hercbios.com
X del hercbios.exe
X
Xhercbios.obj : hercbios.asm hercbios.h
X masm hercbios,,;
X
Xgchar.obj : gchar.asm hercbios.h
X masm gchar,,;
X
Xgraph.obj : graph.asm hercbios.h
X masm graph,,;
X
X
X#
X# Makes for the demo & test program, using Lattice
X# (Note: you may have to change the drive and path specs)
X#
X
Xtestpix.exe : testpix.obj hercpixl.obj
X link g:\lc\s\c testpix hercpixl,testpix,testpix/m,g:\lc\s\lc
X
Xtestpix.obj : testpix.c
X lc -ms -n -ig:\lc\ testpix
X
Xhercpixl.obj : hercpixl.c
X lc -ms -n -ig:\lc\ hercpixl
SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > hercpixl.dc
X/*
X * HERCPIXL.C
X * Dave Tutelman - last modified 8/86
X *
X * This is a set of basic graphic routines for the Hercules
X * Board (or at least the SuperComputer version of it; I assume
X * that they work with the real thing).
X * alfa () puts us in alphanumeric mode.
X * grafix (page) puts us in graphics mode in page 0 or 1
X * pixel (x,y,val) puts a pixel at <x,y>. Bright dot if
X * val=1, dark dot if val=0.
X * dchar (x,y,c) puts character "c" at <x,y>. Note that
X * character raster is 90 x 29.
X * swpage (page) switches to a different page.
X * waitkey () just waits till a key is pressed.
X *
X * Actually, the routines should work with any board, since the
X * BIOS calls are used throughout. It's Hercules-specific only
X * because I've defined the graphics and alpha modes for my
X * Hercules BIOS.
X *
X * Compile with deSmet C.
X */
X
X#define VIDI 0x10 /* video interrupt, normally 10H */
X#define KBD 0x16 /* keyboard interrupt */
X#define ALFA_MODE 7 /* monochrome alpha mode */
X#define GRAF_MODE 8 /* Hercules graphics mode */
X
Xint page = 0;
Xextern unsigned _rax,_rbx,_rcx,_rdx;
X
X/*
X * This puts us back in alphanumeric mode
X */
X
Xalfa (dummy)
X unsigned int dummy;
X{
X _rax = ALFA_MODE; /* mono 80-col mode */
X _doint ( VIDI ); /* set mode */
X}
X
X/*
X * This one switches us to hercules graphics mode
X * in page 0 or 1
X */
X
Xgrafix (newpage)
X int newpage;
X{
X
X _rax = GRAF_MODE; /* herc grafix mode */
X _doint ( VIDI ); /* set mode */
X
X /* now set the page */
X swpage (newpage);
X}
X
X/*
X * This writes a pixel at (x,y), where (0,0) is the upper-left
X * corner of the screen. If val = 0 then the pixel is erased.
X */
X
Xpixel (x, y, val)
X int x, y, val;
X{
X
X _rax = 0x0C00 + val; /* function 12 */
X _rcx = x;
X _rdx = y;
X _doint ( VIDI ); /* set mode */
X
X}
X
X
X/*
X * dchar (x,y,c) puts character "c" at <x,y>. Note that
X * character raster is 90 x 25.
X */
X
Xdchar (x,y,c)
X int x,y;
X char c;
X{
X
X _rax = 2*256; /* AH=Fn#2 */
X _rdx = 256*y + x; /* DH=row, DX=col */
X _rbx = page * 256; /* BH=page */
X _doint (VIDI); /* set cursor */
X
X _rax = 10*256 + (int) c; /* AH=Fn#10, AL=char */
X _rbx = page * 256; /* BH=page */
X _rcx = 1; /* CX=count */
X _doint (VIDI); /* write character */
X}
X
X
X/*
X * This one switches us to a different page, without changing
X * the contents of that page.
X */
X
Xswpage (newpage)
X int newpage;
X{
X page = newpage;
X _rax = 0x500 + page; /* new page function */
X _doint ( VIDI ); /* interrupt call */
X}
X
X
Xwaitkey ()
X{
X _rax = 0; /* keyboard blocking read function */
X _doint (KBD);
X}
SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > hercpixl.lc
X/*
X * HERCPIXL.C
X * Dave Tutelman - last modified 8/86
X *
X * This is a set of basic graphic routines for the Hercules
X * Board (or at least the SuperComputer version of it; I assume
X * that they work with the real thing).
X * alfa () puts us in alphanumeric mode.
X * grafix (page) puts us in graphics mode in page 0 or 1
X * pixel (x,y,val) puts a pixel at <x,y>. Bright dot if
X * val=1, dark dot if val=0.
X * dchar (x,y,c) puts character "c" at <x,y>. Note that
X * character raster is 90 x 29.
X * swpage (page) switches to a different page.
X * waitkey () just waits till a key is pressed.
X *
X * Actually, the routines should work with any board, since the
X * BIOS calls are used throughout. It's Hercules-specific only
X * because I've defined the graphics and alpha modes for my
X * Hercules BIOS.
X *
X * Modified for Lattice C: Reid L. Brown
X * 9/4/86
X */
X
X#define VIDI 0x10 /* video interrupt, normally 10H */
X#define KBD 0x16 /* keyboard interrupt */
X#define ALFA_MODE 7 /* monochrome alpha mode */
X#define GRAF_MODE 8 /* Hercules graphics mode */
X
Xint page = 0;
Xstruct {
X unsigned ax,bx,cx,dx,si,di;
X } _r;
X
X/*
X * This puts us back in alphanumeric mode
X */
X
Xalfa (dummy)
X unsigned int dummy;
X{
X _r.ax = ALFA_MODE; /* mono 80-col mode */
X int86 ( VIDI, &_r, &_r); /* set mode */
X}
X
X/*
X * This one switches us to hercules graphics mode
X * in page 0 or 1
X */
X
Xgrafix (newpage)
X int newpage;
X{
X
X _r.ax = GRAF_MODE; /* herc grafix mode */
X int86 ( VIDI, &_r, &_r); /* set mode */
X
X /* now set the page */
X swpage (newpage);
X}
X
X/*
X * This writes a pixel at (x,y), where (0,0) is the upper-left
X * corner of the screen. If val = 0 then the pixel is erased.
X */
X
Xpixel (x, y, val)
X int x, y, val;
X{
X
X _r.ax = 0x0C00 + val; /* function 12 */
X _r.cx = x;
X _r.dx = y;
X int86 ( VIDI, &_r, &_r); /* set mode */
X
X}
X
X
X/*
X * dchar (x,y,c) puts character "c" at <x,y>. Note that
X * character raster is 90 x 25.
X */
X
Xdchar (x,y,c)
X int x,y;
X char c;
X{
X
X _r.ax = 2*256; /* AH=Fn#2 */
X _r.dx = 256*y + x; /* DH=row, DX=col */
X _r.bx = page * 256; /* BH=page */
X int86 ( VIDI, &_r, &_r); /* set cursor */
X
X _r.ax = 10*256 + (int) c; /* AH=Fn#10, AL=char */
X _r.bx = page * 256; /* BH=page */
X _r.cx = 1; /* CX=count */
X int86 ( VIDI, &_r, &_r); /* write character */
X}
X
X
X/*
X * This one switches us to a different page, without changing
X * the contents of that page.
X */
X
Xswpage (newpage)
X int newpage;
X{
X page = newpage;
X _r.ax = 0x500 + page; /* new page function */
X int86 ( VIDI, &_r, &_r ); /* interrupt call */
X}
X
X
Xwaitkey ()
X{
X _r.ax = 0; /* keyboard blocking read function */
X int86 (KBD, &_r, &_r );
X}
SHAR_EOF
echo x - extracting shar
sed 's/^X//' << 'SHAR_EOF' > testpix.c
X
X/* MAIN tests PIXEL by drawing lines on the screen */
X
X#include "stdio.h"
X
Xmain ()
X{
X int i,j;
X char line [90];
X
X /* first clear screen */
X grafix (0);
X
X /* now draw a couple of lines */
X for (i=0; i<696; i++)
X {
X pixel (i, i/2, 1);
X pixel (i, 348 - i/2, 1);
X }
X
X waitkey(); /* wait for CR */
X
X /* a different pattern on page 1 */
X swpage (1);
X for (i=0; i<720; i++)
X for (j=0; j<348; j=j+50)
X pixel (i,j,1);
X for (i=0; i<720; i=i+90)
X for (j=0; j<348; j++)
X pixel (i,j,1);
X
X /* switch back and forth a couple of times */
X waitkey();
X swpage (0);
X waitkey();
X swpage (1);
X waitkey();
X swpage (0);
X waitkey();
X swpage (1);
X waitkey();
X
X#ifndef NOTONE
X /* add some writing */
X dline (10, 4, "Hello, there!");
X dline (10, 5, "Second LINE of text.");
X dline (10, 6, "all on display page 1.");
X
X waitkey();
X for (i=0; i<8; i++)
X for (j=0; j<32; j++)
X dchar (j+5, i+13, (char) (32*i+j));
X
X waitkey();
X#endif
X /* repeat for page 0 */
X swpage (0);
X
X#ifndef NOTZERO
X /* add some writing */
X dline (10, 4, "Hello, there!");
X dline (10, 5, "Second LINE of text.");
X dline (10, 6, "this time on display page 0.");
X
X waitkey();
X for (i=0; i<8; i++)
X for (j=0; j<32; j++)
X dchar (j+5, i+13, (char) (32*i+j));
X#endif
X
X waitkey();
X
X /* back to alpha mode */
X waitkey();
X alfa();
X}
X
Xdline (x, y, chstr) /* write character-string at x,y */
X int x,y;
X char chstr [90];
X{
X int i;
X char *p;
X
X i=0;
X for ( p=chstr; *p != '\0'; p++ )
X {
X dchar ( x+i, y, *p );
X i++;
X }
X}
SHAR_EOF
exit
