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Assembly Source File | 1987-03-23 | 39.9 KB | 1,365 lines

;====================================================================== ; SLASHBAR is a memory resident interpreter for files prepared by the ; MAKEBAR utility. Bar-menu Description Files (.BDF) are first prepared ; to contain the keystrokes and prompts needed to perform the functions. ; The .BDF file is then or compiled to a BAR file. This ; file is loaded on the command line. ; ; Usage: SLASHBAR [path\]menuname [/n] ; where /n is the size buffer to allocate. /n is only valid for the ; first load and is specified in bytes. For obvious reasons it ; should be as large as the largest .BAR file you will use < 60K. ;---------------------------------------------------------------------- LO_MEM SEGMENT AT 0000H ORG 41AH BIOS_HEAD DW ? BIOS_TAIL DW ? BIOS_BUF DW 16 DUP (?) LO_MEM ENDS ;====================================================================== CSEG SEGMENT PARA PUBLIC 'CODE' ORG 100H ;COM file format STACK LABEL WORD ;Use PSP as stack when res. ASSUME CS:CSEG,DS:CSEG,ES:CSEG,SS:CSEG ;---------------------------------------------------------------------- ; Equates - substituted literally when assembled. ;---------------------------------------------------------------------- CR EQU 0DH ;HEX for carriage return LF EQU 0AH ; and line feed ;ALT-RIGHT SHIFT-TILDE HOTKEY EQU 35H ;SCAN code activating key SHIFT_MASK EQU 08H ;Mask to pick out 'shifts' ;1000 = ALT 0100 = CTRL ;0010 = L.SHIFT 0001 = R SHIFT NROW EQU 4 ;Number of rows in the window NCOL EQU 80 ;Number of cols in the window BOX_COL EQU 0 ;Left col of window on screen BOX_ROW EQU 0 ;Top of screen BW_ATTR EQU 7007H ;Monochrome window CO_ATTR EQU 0417H ;Color window SPACE EQU 20H ;Equivalents for some keys ESC_KEY EQU 1BH BS_KEY EQU 08H TAB_KEY EQU 09H RIGHT_ARROW EQU 4DH LEFT_ARROW EQU 4BH HOME_KEY EQU 47H END_KEY EQU 4FH MAX_CMD_VAL EQU 10 ;Use for error checking ;---------------------------------------------------------------------- ; COM file entry point is at 100h ;---------------------------------------------------------------------- ENTPT: JMP INITIALIZE ;Perform initialization COPYRIGHT DB "SlashBar 1.0 (c) 1987, Ziff-Davis Publishing Corp." DB CR,LF,"$",1AH DB "Robert L. Hummel" ;---------------------------------------------------------------------- ; Data used by INT_9 procedure. Other data precedes other procedures. ;---------------------------------------------------------------------- OLD_INT_9 DD 0 ;Storage for old vectors OLD_INT_16 DD 0 OLD_INT_21 DD 0 DOS_FLAG DD 0 ;Address of dos critical flag ACTIVE DB 0 ;Inside pop-up LO_FN_FLAG DB 0 ;When inside Int 21h DISPLAY_PAGE DB 0 ;Used by screen save CURSOR_POS DW 0 ; to restore info OLD_SS DW 0 ;To save stack OLD_SP DW 0 ; during switching ;====================================================================== ; New Interrupt 9 routine. Invoked each key-press. ; Test to see if our key combination has been typed. ;---------------------------------------------------------------------- INT_9 PROC FAR ASSUME CS:CSEG, DS:NOTHING, ES:NOTHING, SS:NOTHING ;(Flags saved by INT) STI ;Allow interrupts PUSH AX ;Save used register IN AL,60H ;Get key scan code CMP AL,HOTKEY ;Check if hot-key JNE PROCESS_KEY ;If not, continue on. MOV AH,2 ;Get shift status fn INT 16H ;Thru BIOS AND AL,0FH ;Test only for 'shift' keys CMP AL,SHIFT_MASK ;If they match our combination JE OUR_KEY ;then is our signal PROCESS_KEY: POP AX ;Restore register JMP DWORD PTR CS:OLD_INT_9 ;Process key as normal OUR_KEY: ;---------------------------------------------------------------------- ; Reset the keyboard interrupt controller (forget the key stroke) ;---------------------------------------------------------------------- IN AL,61H ;These instructions reset MOV AH,AL ; the keyboard. OR AL,80H OUT 61H,AL MOV AL,AH JMP SHORT $+2 ;I/O delay OUT 61H,AL CLI ;Disable interrupts and MOV AL,20H ;reset the int controller OUT 20H,AL STI ;Allow interrupts ;---------------------------------------------------------------------- ; If program is already active, or DOS is busy, simply return. ;---------------------------------------------------------------------- CMP CS:ACTIVE,0 ;If already active, can't call JNE RETURN_A MOV AX,CS:KEY_PTR ;If head of our key buffer CMP AX,CS:KEY_TAKE ; isn't = tail JNE RETURN_A ; we still have keys to lose INC CS:ACTIVE ;Turns off BIOS flag in INT_16 MOV AH,1 ;If the BIOS key buffer INT 16H ; has keys in it MOV CS:ACTIVE,0 JNZ RETURN_A ; don't pop up PUSH DS ;Save used registers PUSH BX LDS BX,CS:DOS_FLAG ;If DOS critical flag is not CMP BYTE PTR [BX],0 ; busy JE INVOKE ;We can pop up CMP CS:LO_FN_FLAG,0 ;If busy from low function JNE INVOKE ; go pop up RETURN_B: POP BX ;Restore other registers POP DS RETURN_A: POP AX ;Restore register IRET ;Go back where we came from INVOKE: ;---------------------------------------------------------------------- ; From the video mode, determine the box colors to use. ;---------------------------------------------------------------------- MOV WORD PTR CS:NCLR,CO_ATTR ;Use color window MOV AH,0FH ;Get current video mode fn CALL VIDEO ;Thru BIOS MOV CS:DISPLAY_PAGE,BH ;Save current page ;Valid video modes are: CMP AL,1 ;COLOR 40X25 JZ MODE_OK CMP AL,3 ;COLOR 80x25 JE MODE_OK MOV WORD PTR CS:NCLR,BW_ATTR ;Default to mono window CMP AL,7 ;MONO 80x25 JE MODE_OK CMP AL,2 JA RETURN_B ;Go back from whence we came MODE_OK: ;---------------------------------------------------------------------- ; If here, routine becomes active, save all other used registers. ;---------------------------------------------------------------------- MOV CS:ACTIVE,1 ;Set flag to prevent re-entry PUSH CX ;Save all registers for return PUSH DX PUSH DI PUSH SI PUSH ES PUSH BP MOV AX,CS ;Put our CS into these regs MOV DS,AX ;So we can find our data MOV ES,AX ;And our string moves ASSUME DS:CSEG,ES:CSEG ;Tell the Assembler MOV OLD_SS,SS ;Swap stacks after all MOV OLD_SP,SP ; registers are pushed CLI ;Turn off interrupts MOV SS,AX ;Put our stack in place MOV SP,OFFSET STACK STI ;Interrupts on ASSUME SS:CSEG ;Tell the Assembler ;---------------------------------------------------------------------- ; Save the details of the current screen for later restoration. ;---------------------------------------------------------------------- MOV AH,3 ;Get cursor position fn CALL VIDEO ;Thru BIOS MOV CURSOR_POS,DX ;Save position for ;restoration on exit ;---------------------------------------------------------------------- ; Save section of screen we will be writing over. ;---------------------------------------------------------------------- MOV DI,OFFSET SCREEN_BUF ;Destination for save MOV SI,0FFFFH ;Switch for proc to save CALL SCREEN ;---------------------------------------------------------------------- ; Perform specific function. ;---------------------------------------------------------------------- CALL CLR_BOX ;Draw box & border CALL MENU_TIME CANCEL: ;---------------------------------------------------------------------- ; Restore the screen to original state. ;---------------------------------------------------------------------- MOV SI,OFFSET SCREEN_BUF CALL SCREEN MOV AH,2 ;Set Cursor position fn MOV DX,CURSOR_POS ;Restore old cursor position CALL VIDEO ;Thru BIOS MOV AX,OLD_SS ;Restore previous stack MOV BX,OLD_SP CLI ;No interrupts MOV SS,AX MOV SP,BX STI ;Allow interrupts MOV ACTIVE,0 ;Turn off active flag POP BP ;Restore all used registers POP ES POP SI POP DI POP DX POP CX POP BX POP DS POP AX IRET ;Interrupt gets IRET INT_9 ENDP ;====================================================================== ; BIOS Video Interrupt. Some older versions of the BIOS destroy the ; BP register inside the video routine. ;---------------------------------------------------------------------- VIDEO PROC NEAR PUSH BP ;Preserve register INT 10H ;Call to BIOS POP BP ;Restore RET VIDEO ENDP ;====================================================================== ; Perform the screen save/restore. ; SAVE: SI=FFFF, DI=buffer address ; RESTORE: SI=buffer address, DI=don't care ;---------------------------------------------------------------------- SCREEN PROC NEAR ASSUME CS:CSEG, DS:CSEG, ES:CSEG, SS:NOTHING CLD ;String moves forward MOV BH,DISPLAY_PAGE ;Just to be sure, reset page MOV CX,NROW ;Row loop MOV ROW,BOX_ROW ;Init row pointer ROW_LOOP: PUSH CX ;Prepare for... MOV CX,NCOL ;...column loop MOV COL,BOX_COL ;Column Pointer COL_LOOP: CMP SI,0FFFFH ;SI =FFFF if SAVE JE DO_SAVE ;RESTORE LODSW ;AX <- [SI] ;AH=ATTR AL=CHAR CALL CRT_CHAR ;Write char to screen JMP SHORT DO_LOOP DO_SAVE: CALL SET_CUR ;Position cursor MOV AH,8 ;Get char & attribute fn CALL VIDEO ;Thru BIOS STOSW ;[di+=2]=ax DO_LOOP: INC COL ;Next column LOOP COL_LOOP ;Close Inner loop POP CX ;Return to outer loop INC ROW ;Next row LOOP ROW_LOOP ;Close Outer loop RET SCREEN ENDP ;====================================================================== ; Clear a window (box) for our information on the screen. ; Add a border for a nice touch. ;---------------------------------------------------------------------- BOX_MSG DB BOX_COL+2,BOX_ROW,0B5H,"SlashBar 1.0",0C6H,0 BOX_CHARS DB 0C9H,0CDH,0BBH,0BAH,020H,0BAH,0C8H,0CDH,0BCH CLR_BOX PROC NEAR MOV AX,0600H ;Scroll entire window fn MOV CH,BOX_ROW ;Upper row MOV ROW,CH MOV CL,BOX_COL ;Left column MOV DH,BOX_ROW + NROW - 1 ;Lower row MOV DL,BOX_COL + NCOL - 1 ;Right column MOV BH,NCLR ;Window color CALL VIDEO ;Thru BIOS MOV BH,DISPLAY_PAGE ;This page MOV AH,NCLR ;This color MOV SI,OFFSET BOX_CHARS ;Source of characters MOV DX,CX ;Cursor from last call MOV CX,NROW ;Number of rows to draw CB_1: PUSH CX ;Save counter MOV COL,BOX_COL ;Set column LODSB ;Get leftmost char CALL CRT_CHAR ; write to screen LODSB ;Get middle char MOV CX,NCOL-2 ;Number copies to write CB_1A: INC COL ;Next column CALL CRT_CHAR ;Write char to screen LOOP CB_1A INC COL ;Last column LODSB ;Get rightmost char CALL CRT_CHAR ; put on screen INC ROW ;Next row POP CX ;Restore counter CMP CL,NROW ;If written last row JE CB_2 ; put new chars CMP CL,2 ;If 2nd row JE CB_2 ; get new chars SUB SI,3 ;back up & repeat CB_2: LOOP CB_1 ;Loop each line MOV SI,OFFSET BOX_MSG ;Put program name LODSW ; at this row,col MOV CURSOR_LOC,AX MOV AH,NCLR ; and this color CALL CRTZ ; on screen RET CLR_BOX ENDP ;====================================================================== ; DOS Int 21h intercept. Set flag while uninterruptable ; The purpose of this procedure is to keep pop-up from taking control ; of the machine when doing so would cause a crash. ;---------------------------------------------------------------------- INT_21 PROC FAR CMP AH,0 ;If program is using DOS fn 0 JNE CHECK MOV AH,4CH ;Change it to 4Ch GO_DIRECT: MOV CS:LO_FN_FLAG,0 ;Not function 1-Ch JMP DWORD PTR CS:OLD_INT_21 ;Jump to original routine CHECK: CMP AH,0CH ;DOS functions call under 0DH JA GO_DIRECT MOV CS:LO_FN_FLAG,1 ; set this flag PUSHF ;Simulate INT CALL DWORD PTR CS:OLD_INT_21 ; return here MOV CS:LO_FN_FLAG,0 ;Turn off flag RET 2 ;Return to INT source and ;discard old flags INT_21 ENDP ;====================================================================== ; Int 16 intercept. Use to feed keys to calling programs. ;---------------------------------------------------------------------- LAST_CALL DB 0 ;Remember last call so first or ;last key can be removed INT_16 PROC FAR ASSUME CS:CSEG, DS:NOTHING, ES:NOTHING, SS:NOTHING CMP CS:ACTIVE,0 ;Don't steal our own 'strokes! JNE GOTO_BIOS ; get them thru BIOS CMP AH,2 ;Ignore calls for shift status JAE DONT_SAVE MOV CS:LAST_CALL,AH DONT_SAVE: STI ;Interrupts on PUSH BX ;Save used register MOV BX,CS:KEY_TAKE ;Pointer to next keystroke CMP BX,CS:KEY_PTR ;If no keys in our buffer JE POP_GOTO_BIOS ;Pass thru to BIOS CMP AH,2 ;Request for shift status JE POP_GOTO_BIOS ; goes thru BIOS always CMP AH,0 ;Wait for key JE UNLOAD_KEY CMP AL,1 ;Is key stroke ready? JNE POP_GOTO_BIOS ;return NZ if key ready OR AL,AL ;Generate a NZ POP BX RET 2 ;Discard old flags UNLOAD_KEY: MOV BX,CS:KEY_TAKE ;Get ptr to key in BX MOV AX,CS:[BX] ;Get the key in AX ADD CS:KEY_TAKE,2 ;Move the ptr along POP BX ;Restore register RET 2 ;Discard flags POP_GOTO_BIOS: POP BX GOTO_BIOS: JMP DWORD PTR CS:OLD_INT_16 INT_16 ENDP ;======================================================================= ; INTERPRETER - Read the contents of menu file and perform functions. ; BP always contains the address of the start of the MENU buffer. ; NOTE: THIS PROGRAM MAKES USE OF THE FACT THAT A .COM FILE ; HAS CS=DS=ES=SS WHEN USING ADDRESSING WITH BP. ; THEREFORE, SET UP A STACK USING THE CS SEGMENT. ;---------------------------------------------------------------------- ; Data structures. ;---------------------------------------------------------------------- MENU_BASE DW FILE_DTA ;Real address of offset 0 DTA_SIZE DW 4096 ;4k bytes by default OPT_PTR DW 0 ;Points to menu choice LEVEL DW 0 ;Depth of menu tree NOPT DW 0 ;Number options this menu KEY_PTR DW KEYS ;Points to next empty spot KEY_TAKE DW KEYS ;Points to available char CMD_TABLE DW ASK, CR_CMD, EXECUTE, INPUT, BAD_CMD, BAD_CMD DW BAD_CMD, TYPE_KEY, BAD_CMD, BAD_CMD, SEND CURSOR_LOC LABEL WORD COL DB 0 ;Display column ROW DB 0 ; row NCLR DB 07H ;Normal video color RCLR DB 70H ;Reverse video color ;======================================================================= ; Prime the pointers with their initial values. ;---------------------------------------------------------------------- ASSUME CS:CSEG,DS:CSEG,ES:CSEG,SS:CSEG MENU_TIME PROC NEAR CLD ;String moves forward XOR DI,DI ;DI = 0 MOV AX,OFFSET KEYS ;Initialize key buffer MOV KEY_PTR,AX MOV KEY_TAKE,AX MOV WORD PTR KEY_STK [DI],AX ;Starting KEY_PTR in stack MOV WORD PTR MENU_STK[DI],10 ;Offset into menu in stack MOV OPT_PTR,DI ;Point to option 0 MOV LEVEL,DI ;We're at level 0 MOV BP,MENU_BASE ;Always points to menu base ;---------------------------------------------------------------------- ; Put the PROGRAM name on the screen. ;---------------------------------------------------------------------- MOV ROW,BOX_ROW ;This row & column MOV COL,BOX_COL + NCOL - 12 MOV AH,NCLR ;Normal color attribute MOV AL,0B5H ;Char to write CALL CRT_CHAR ;Write to screen MOV SI,BP ;Point to program name MOV CX,10 ;Maximum chars to write MT_1: INC COL ;Next column LODSB ;Get char at DS:SI OR AL,AL ;If 0 JZ MT_2 ; end of string CALL CRT_CHAR ; else, write it LOOP MT_1 ; and continue MT_2: MOV AL,0C6H ;Close box CALL CRT_CHAR ;Write char ;---------------------------------------------------------------------- ; Menus are built from scratch. ;---------------------------------------------------------------------- BUILD_MENU: CALL CLR_LINES ;Clear inside of window MOV DI,LEVEL ;The menu level SHL DI,1 ; *2 for word access MOV AX, WORD PTR KEY_STK[DI] ;Point to next key save point MOV KEY_PTR,AX ; and put where it's used CALL GET_MENU_HEAD ;Offset of menu in DI MOV AX,[BP][DI] ;Offset 0 has number opts MOV NOPT,AX CALL WRITE_NAMES ;Write the option names CALL WRITE_HELP ;Write the help lines CALL GET_KEY ;From user OR AL,AL ;AL = 0 If extended ascii JNZ ASCII_KEY CALL MOVE_BAR ;Could be left/right arrow JMP BUILD_MENU ; or home/end ;---------------------------------------------------------------------- ; ASCII key could be option letter, CR, ESC, or mistake. ;---------------------------------------------------------------------- ASCII_KEY: CALL MAKE_UC ;Make AL upper case CALL MATCH_KEY ;Return NC if match and ; AL contains option # JNC MATCH_FOUND ;No match found CALL BEEP JMP BUILD_MENU MATCH_FOUND: CMP AL,0FFH ;AL=FF if ESC JNE READ_SCRIPT ;Else, perform functions ;---------------------------------------------------------------------- ; The ESC key was hit. Back up one menu. If at top menu, exit. ; backing up removes any keystrokes put in by the current menu. ;---------------------------------------------------------------------- CMP LEVEL,0 ;If at top menu JE CANCEL_MENU ; leave DEC LEVEL ;Back up MOV OPT_PTR,0 JMP BUILD_MENU ;Reconstruct display CANCEL_MENU: MOV KEY_PTR,OFFSET KEYS ;Flush the buffer RET ;Return & Exit ;---------------------------------------------------------------------- ; Interpret the option script. ;---------------------------------------------------------------------- READ_SCRIPT: CALL GET_MENU_HEAD ;Set DI = menu offset MOV AX,OPT_PTR ;Each option takes 6 bytes INC AX ;Extra 6 to point to token ptr MOV BL,6 ;3 words = 6 bytes MUL BL ;Gives Additional offset in AX ADD DI,AX ;DI is offset from menu head MOV SI,[BP][DI] ;SI is offset to token ADD SI,BP ;Real address GET_TOKEN: LODSB ;Get command token MOV BL,AL ;Put in base register CMP BL,MAX_CMD_VAL JA BAD_CMD SHL BL,1 ;*2 for word access XOR BH,BH ;Top is 0 JMP CMD_TABLE[BX] ;Execute based on value BAD_CMD: ;If here, the .BAR file is bad, no recovery ;Use the save exit as a top-level-escape JMP CANCEL_MENU ;---------------------------------------------------------------------- ; ASK: Type the following string in the window ; 1st line is used for queries. ;---------------------------------------------------------------------- ASK: CALL CLR_LINES ;Clear inside of window MOV ROW,BOX_ROW + 1 ;Position the cursor MOV COL,BOX_COL + 2 MOV AH,NCLR ;Attribute to use CALL CRTZ ;Copy chars till 0 JMP GET_TOKEN ;Get next instruction ;---------------------------------------------------------------------- ; CR: Put a CR in the buffer. ;---------------------------------------------------------------------- CR_CMD: MOV AX,1C0DH ;Put a carriage return CALL SAVE_KEY ; in our key buffer JMP GET_TOKEN ;Get next instruction ;---------------------------------------------------------------------- ; EXECUTE: transfer control to a lower menu. ;---------------------------------------------------------------------- EXECUTE: INC LEVEL ;Next menu level MOV DI,LEVEL ;Convert to index CMP DI,32 ;Maximum level of menus JB LEVEL_OK MENU_ERROR: CALL BEEP ;Sound off! JMP CANCEL_MENU ;And leave no trace LEVEL_OK: SHL DI,1 ;Index into tables MOV AX,KEY_PTR ;Save current key_ptr MOV WORD PTR KEY_STK[DI],AX ; to restore ;Following token is LODSW ; offset of new menu MOV WORD PTR MENU_STK[DI],AX ;Saved in "stack" MOV OPT_PTR,0 JMP BUILD_MENU ;Make new picture ;---------------------------------------------------------------------- ; INPUT: Accept keystrokes from the user until CR. ; 2nd line is used for responses. ;---------------------------------------------------------------------- INPUT: CALL BUFFERED_INPUT ;Buffered input from console JNC GET_TOKEN ;NC if all went ok JMP BUILD_MENU ;Else rebuild menu ;---------------------------------------------------------------------- ; TYPE: Put the following keystrokes into the key buffer. ;---------------------------------------------------------------------- TYPE_KEY: XOR AH,AH ;High byte is 0 LODSB ;Get char in AL OR AL,AL ;0 If end of sequence JE GET_TOKEN ;Look for next command CMP AL,0FEH ;Extended ascii switch JNE TYPE_1 ;Put char out as is LODSB ;Get extended code CMP AL,0FEH JNE TYPE_A MOV AX,1C0AH ;Double FE FE = ctrl-enter JMP SHORT TYPE_2 TYPE_A: XCHG AH,AL ;Put code in high byte JMP SHORT TYPE_2 ;Stuff in buffer TYPE_1: MOV AH,1CH ;Add the high bytes to CMP AL,CR ; these selected keys JE TYPE_2 ; for compatibility MOV AH,1 CMP AL,ESC_KEY JE TYPE_2 MOV AH,0EH CMP AL,BS_KEY JE TYPE_2 CMP AL,7FH JE TYPE_2 INC AH CMP AL,TAB_KEY JE TYPE_2 XOR AH,AH TYPE_2: CALL SAVE_KEY ;Put in KEYS buffer JMP TYPE_KEY ;Try again ;---------------------------------------------------------------------- ; SEND: Signal the end of the pop-up task. ;---------------------------------------------------------------------- SEND: MOV BX,KEY_PTR ;Pointer to next keystroke CMP BX,KEY_TAKE ;If no keys in our buffer JE MENU_EXIT ;No action needed CMP LAST_CALL,0 ;If last call was wait-for-key JE USE_FIRST_KEY ; stuff first key in buffer SUB KEY_PTR,2 ;Point to last valid key SUB BX,2 ; move the pointer JMP SHORT REMOVE_KEY ;Put in BIOS buffer USE_FIRST_KEY: MOV BX,KEY_TAKE ;Remove first key ADD KEY_TAKE,2 ; advance pointer REMOVE_KEY: MOV CX,WORD PTR [BX] ;Take out the LAST key PUSH DS ;Set up for low memory access XOR AX,AX MOV DS,AX ASSUME DS:LO_MEM MOV BX,OFFSET BIOS_HEAD ;Start of bios key buffer CLI MOV WORD PTR [BX][0],001EH ;Set the head MOV WORD PTR [BX][2],0020H ;Set the Tail MOV WORD PTR [BX][4],CX ;Put key in buffer STI ;Allow interrupts POP DS ;Restore the register ASSUME DS:CSEG ;Tell the assembler MENU_EXIT: RET MENU_TIME ENDP ;====================================================================== ; Put offset of current menu_head into DI. MENU_STK[LEVEL*2] ; DI changed. Other registers preserved. ;---------------------------------------------------------------------- GET_MENU_HEAD PROC NEAR MOV DI,LEVEL SHL DI,1 MOV DI,WORD PTR MENU_STK[DI] RET GET_MENU_HEAD ENDP ;====================================================================== ; Write the current menu option choices to the screen. ; AX,CX,DX,SI,DI changed. Others preserved. ;---------------------------------------------------------------------- WRITE_NAMES PROC NEAR MOV ROW,BOX_ROW + 1 ;Position is one row down MOV COL,BOX_COL + 1 ;1 col over XOR DX,DX ;Option counter MOV CX,NOPT ;Number of options this menu CALL GET_MENU_HEAD ;In DI WN_1: MOV SI,[BP][DI][2] ;SI is offset to name ADD SI,BP ;SI points to name WN_2: MOV AH,NCLR ;Normal color MOV AL,SPACE ; with a space INC COL ;Separate the names CALL CRT_CHAR CMP OPT_PTR,DX ;Is this the current option JNE WN_3 MOV AH,RCLR ;Yes, use reverse color WN_3: CALL CRTZ ;Copy until 0 to CRT INC DX ;1 string complete ADD DI,6 ;Point to next ptr to name LOOP WN_1 ;Repeat for number of options RET WRITE_NAMES ENDP ;====================================================================== ; Write the help line for the current option below the names. ; AX,BX,SI,DI changed. Others preserved. ;---------------------------------------------------------------------- WRITE_HELP PROC NEAR MOV ROW,BOX_ROW + 2 MOV COL,BOX_COL + 2 CALL GET_MENU_HEAD MOV AX,OPT_PTR ;3 WORD offset for each opt MOV BL,6 MUL BL ;Gives Additional offset in AX ADD DI,AX ;DI is ptr to offset of help MOV SI,[BP][DI][4] ;SI is offset ptr to help ADD SI,BP MOV AH,NCLR ;Normal color CALL CRTZ ;Write string to CON RET WRITE_HELP ENDP ;====================================================================== ; Read a key from the console with no echo. ; Return in AX. Other registers preserved. ;---------------------------------------------------------------------- GET_KEY PROC NEAR XOR AH,AH ;AH=0, wait for key INT 16H ; Thru BIOS RET GET_KEY ENDP ;====================================================================== ; Keystroke was extended ascii. If left/right arrow, move opt_ptr. ; BX,CX changed. Other registers preserved. ;---------------------------------------------------------------------- MOVE_BAR PROC NEAR MOV BX,OPT_PTR ;Current position MOV CX,NOPT ;Maximum position is # opt DEC CX ; minus one CMP AH,RIGHT_ARROW ;Move right JNE MB_1 INC BX ;Increase pointer CMP BX,CX ;Past max? JBE MB_EXIT ;No, exit MB_0: XOR BX,BX ;Yes, reset to 0 JMP SHORT MB_EXIT ;and leave MB_1: CMP AH,LEFT_ARROW ;Move left JNE MB_2 DEC BX ;Decrease pointer JNS MB_EXIT ;Did it go negative? MB_1A: MOV BX,CX ; yes, wrap to max MB_EXIT: MOV OPT_PTR,BX ;Change pointer RET ;Leave MB_2: CMP AH,HOME_KEY ;Home - go to 0 JE MB_0 MB_3: CMP AH,END_KEY ;End - move to max JE MB_1A CALL BEEP RET MOVE_BAR ENDP ;====================================================================== ; Make the character in AL UPPER case. ;---------------------------------------------------------------------- MAKE_UC PROC NEAR CMP AL,'a' JB UC_1 CMP AL,'z' JA UC_1 SUB AL,20H UC_1: RET MAKE_UC ENDP ;====================================================================== ; Search current names for matching first letter. Return CY if no match. ; If CR, choose current option, and return in AL. If ESC, set AL=FF. ; AX,BX,DX changed. Others preserved. ;---------------------------------------------------------------------- MATCH_KEY PROC NEAR CMP AL,ESC_KEY ;If ESC key hit JNE MK_0 MOV AL,0FFH ;Signal code MK_CLC: CLC MK_EXIT: RET ;Return MK_0: MOV BX,AX ;Save key MOV AX,OPT_PTR ;Current option in AL CMP BL,CR ;If CR struck JE MK_CLC ;Return option number XOR DX,DX ;Option counter MOV CX,NOPT ;Number of options this menu CALL GET_MENU_HEAD ;In DI MK_1: MOV SI,[BP][DI][2] ;SI is offset to name ADD SI,BP ;SI points to opt name LODSB ;Get first letter in AL CMP AL,BL ;Does key match? JE MK_2 INC DX ;Next option count ADD DI,6 ;Point to next ptr to name LOOP MK_1 ;Repeat for number of options STC ;Match not found RET MK_2: MOV AX,DX ;Put option match in AL MOV OPT_PTR,AX ;And in pointer JMP MK_CLC MATCH_KEY ENDP ;====================================================================== ; Copy an ASCIIZ string to the console at the current cursor location. ; Cursor position is updated. SI points to string and is moved. AH ; contains the attribute to used for the string. ; AX,SI changed. Other registers preserved. ;---------------------------------------------------------------------- CRTZ PROC NEAR CRTZ_1: LODSB ;Get character OR AL,AL ;If char is 0 JE CRTZ_2 ; end of string CALL CRT_CHAR INC COL JMP CRTZ_1 CRTZ_2: RET CRTZ ENDP ;====================================================================== ; Output the char in AL at the stored cursor position. ; AH contains the attribute to be used. ; Preserve all registers. ;---------------------------------------------------------------------- CRT_CHAR PROC NEAR PUSH AX ;Save used registers PUSH BX PUSH CX CALL SET_CUR ;Set the cursor MOV CX,1 ;Write 1 char MOV BL,AH ;Use this attribute MOV AH,9 ;Write char & attr MOV BH,DISPLAY_PAGE ;This page CALL VIDEO ; Thru BIOS POP CX ;Restore registers POP BX POP AX RET CRT_CHAR ENDP ;====================================================================== ; Clear the line in AL. AX,BX,CX,DX destroyed. ;---------------------------------------------------------------------- CLR_LINES PROC NEAR MOV AX,0600H ;Scroll screen Function MOV CH,BOX_ROW + 1 ;Upper row MOV DH,BOX_ROW + NROW - 2 ;Lower row MOV CL,BOX_COL + 1 ;Left col MOV DL,BOX_COL + NCOL - 2 ;Right col MOV BH,NCLR ;Attribute CALL VIDEO ;BIOS video RET CLR_LINES ENDP ;====================================================================== ; Position the cursor at ROW,COL. ; Preserve all registers. ;---------------------------------------------------------------------- SET_CUR PROC NEAR PUSH AX ;Save used registers PUSH BX PUSH DX MOV DX,CURSOR_LOC ;Load both row & col MOV AH,2 ;Move cursor fn MOV BH,DISPLAY_PAGE ;Current page CALL VIDEO ; Thru BIOS POP DX ;Restore registers POP BX POP AX RET SET_CUR ENDP ;====================================================================== ; Save the key in AX in KEYS buffer ;---------------------------------------------------------------------- SAVE_KEY PROC NEAR PUSH BX ;Save used registers PUSH CX MOV CX,KEY_PTR ;Current pointer MOV BX,CX ; also in BX SUB CX,OFFSET KEYS ;Get # bytes CMP CX,512 ;More than allowed? JE SK_1 ;Simply ignore MOV [BX],AX ;Store key ADD KEY_PTR,2 ;Move pointer SK_1: POP CX ;Restore registers POP BX RET SAVE_KEY ENDP ;====================================================================== ; Read keys from the keyboard until a <CR> ;---------------------------------------------------------------------- BUFFERED_INPUT PROC NEAR PUSH AX ;Save registers PUSH CX PUSH SI BUF_ERASE: MOV ROW,BOX_ROW + 2 ;Position cursor MOV COL,BOX_COL + 1 CALL SET_CUR MOV AX,0A20H ;Fill with blanks MOV BH,DISPLAY_PAGE MOV CX,NCOL - 2 CALL VIDEO ; Thru BIOS MOV SI,OFFSET INKEY_BUF ;Point to start of buffer BUF_1: MOV CX,SI ;Calculate buffer length SUB CX,OFFSET INKEY_BUF ; in CX CALL SET_CUR ;Position cursor CALL GET_KEY ;Read a key from the kbd OR AL,AL ;If low byte is 0 JZ BUF_1 ; not ascii CMP AL,CR ;Enter key JE BUF_CR CMP AL,ESC_KEY ;Escape JE BUF_ESC CMP AL,BS_KEY ;Backspace JE BUF_BS CMP CX,76 * 2 ;Maximum bytes allowed JA BUF_2A BUF_1A: MOV [SI],AX ;Save key in INKEY_BUF ADD SI,2 ;Point to next entry BUF_2: MOV AH,NCLR CALL CRT_CHAR ;Write AL at row,col INC COL ;Next column JMP BUF_1 ;Get more keys BUF_BS: OR CX,CX ;Any keys in buf? JNZ BUF_3 BUF_2A: CALL BEEP JMP BUF_1 BUF_3: SUB SI,2 ;Remove key DEC COL ;Write over char MOV AL,SPACE ; with space MOV AH,NCLR ;Normal color CALL CRT_CHAR ;Do it JMP BUF_1 BUF_ESC: OR CX,CX ;If chars in buf JNZ BUF_ERASE ;Erase them all STC ;Carry means we're backing out JMP SHORT BUF_RET BUF_CR: OR CX,CX ;If no chars JZ BUF_OK ; simply return SHR CX,1 ;Number of words to transfer MOV SI,OFFSET INKEY_BUF CLD BUF_LOOP: LODSW CALL SAVE_KEY LOOP BUF_LOOP BUF_OK: CLC BUF_RET: POP SI ;Restore regs POP CX POP AX RET BUFFERED_INPUT ENDP ;====================================================================== ; Beep at the terminal. ;---------------------------------------------------------------------- BEEP PROC NEAR PUSH AX ;Save register MOV AX,0E07H ;write a 'beel' CALL VIDEO ; Thru BIOS POP AX ;Restore RET BEEP ENDP ;====================================================================== ; Hook the necessary interrupts to avoid a collision. Read command line ; Parameters. Terminate and Stay Resident (TSR). ;---------------------------------------------------------------------- GREEDY_MSG DB "/n Too Big$" BIG_FILE DB "File Too Big$" BAD_FILE_MSG DB "Error Opening File$" USAGE_MSG DB "Usage: SLASHBAR [path]menuname.ext [/n]$" INITIALIZE PROC NEAR ASSUME CS:CSEG, DS:CSEG, ES:CSEG, SS:CSEG MOV DX,OFFSET COPYRIGHT ;Say who we are MOV AH,9 ;Display string function INT 21H ;Thru DOS CALL CHECK_VERSION ;Version 2.0+ or don't return ;---------------------------------------------------------------------- ; Check if already loaded in memory. Don't load multiple copies. ; When this routine ends, ES points to usable copy in memory. It may ; not be the same as CS. ;---------------------------------------------------------------------- MOV WORD PTR [ENTPT+0],0 ;Modify to avoid false match MOV WORD PTR [ENTPT+2],0 XOR BX,BX ;BX = segment to compare MOV AX,CS ;AX = our segment NEXT_PARA: INC BX ;Next paragraph MOV ES,BX ;Set search segment CMP AX,BX ;If current paragraph... JE END_SEARCH ;...stop MOV SI,OFFSET ENTPT ;String to compare MOV DI,SI ;Offset is same MOV CX,16 ;Compare first 16 words REP CMPSW ;CMP DS:SI TO ES:DI OR CX,CX ;All matched? JNZ NEXT_PARA ;No, continue search JMP SHORT SIZE_OK ;Found a copy at ES ;---------------------------------------------------------------------- ; Didn't find a copy in memory. Look for memory size switch. ;---------------------------------------------------------------------- END_SEARCH: MOV DI,80H ;# chars on command line MOV CL,[DI] ; in CL XOR CH,CH ;CH = 0 INC DI ;Point to 1st char MOV AL,'/' ;Look for slash REPNE SCASB ;Do it for CX chars JCXZ SIZE_OK ;No switch on line MOV SI,DI ;Point SI to n parameter DEC DI ;Make sure any file name MOV BYTE PTR [DI],CR ; has return after it MOV DI,10 ;Base 10 (decimal) MOV CX,5 ;Maximum 5 digits XOR BX,BX ;Size in BX GET_MEM_SIZE: LODSB ;Get digit SUB AL,30H ;ASCII to digit CMP AL,9 ;Must be 0-9 JA SAVE_SIZE ; else, end of num XCHG AX,BX ;Put digit in BX MUL DI ;Multiply sum x 10 XOR BH,BH ;Make BX single digit ADD BX,AX ;Sum in BX LOOP GET_MEM_SIZE ;Continue SAVE_SIZE: MOV DTA_SIZE,BX ;Place in variable XOR AX,AX ;Check 64 K limit DEC AX SUB AX,BX CMP AX,OFFSET LAST_BYTE JA SIZE_OK MOV DX,OFFSET GREEDY_MSG ERROR_EXIT: MOV AH,9 ;Display string fn INT 21H ; Thru DOS MOV AX,4C01H ;Terminate with error=1 INT 21H ; Thru DOS SIZE_OK: ;---------------------------------------------------------------------- ; Read the command line for a path/file spec. ; ES may point to the resident copy! ;---------------------------------------------------------------------- MOV SI,81H ;Command line in PSP FIND_START: LODSB ;Get char CMP AL,SPACE ;If a space JE FIND_START ; skip to next char CMP AL,CR ;If NOT CR JNE HAVE_START ; found start of spec MOV DX,OFFSET USAGE_MSG ;CR = error, no file name JMP ERROR_EXIT HAVE_START: MOV DX,SI DEC DX ;Name starts here FIND_END: LODSB ;Get char CMP AL,SPACE ;A space JE NAME_OK CMP AL,CR ;or CR ends name JNE FIND_END NAME_OK: DEC SI ;Back up 1 char MOV BYTE PTR [SI],0 ; make ASCIIZ MOV AX,3D00H ;Open for reading INT 21H ; Thru DOS JNC OPEN_OK FILE_ERR: MOV DX,OFFSET BAD_FILE_MSG JMP ERROR_EXIT OPEN_OK: MOV BX,AX ;Save handle in BX MOV AX,4202H ;Move file pointer XOR CX,CX ; 0 bytes from end XOR DX,DX INT 21H ; Thru DOS JC FILE_ERR CMP AX,DTA_SIZE ;AX has # bytes in file JBE FILE_FINE ;Size OK MOV DX,OFFSET BIG_FILE JMP ERROR_EXIT FILE_FINE: PUSH AX ;Number of bytes to read MOV AX,4200H ;Move file pointer XOR CX,CX ; 0 bytes from start XOR DX,DX INT 21H ; Thru DOS POP CX JC FILE_ERR MOV AH,3FH ;Read file fn MOV DX,OFFSET FILE_DTA ;Put data at this offset PUSH DS ;(Save DS) PUSH ES ;Put ES (resident segment) POP DS ; into DS (DS:DX is DTA) INT 21H ;Thru DOS POP DS ;Restore old DS JC FILE_ERR MOV AH,3EH ;Close file Fn INT 21H ; Thru DOS MOV CX,CS ;Check if ES=CS, i.e., MOV BX,ES ;there is no resident copy CMP CX,BX JE KEEP MOV AX,4C00H INT 21H KEEP: ;---------------------------------------------------------------------- ; Get a pointer to the DOS Critical Flag, a one-byte location in low memory ; that is set when DOS is in an uninterruptable state. Location is returned ; in ES:BX. This is undocumented, but works in DOS 2.0 - 3.21 ;---------------------------------------------------------------------- PUSH ES MOV AH,34H ;Get Interrupt Flag address INT 21H MOV WORD PTR DOS_FLAG[0],BX ;offset MOV WORD PTR DOS_FLAG[2],ES ;segment POP ES ;---------------------------------------------------------------------- ; Hook the keyboard interrupt 9h for the hot-key detection routine. ; Hook Int 16h for BIOS keyboard control. ; Hook DOS Interrupt 21h,25h,26h and BIOS 13h to set busy flags. ;---------------------------------------------------------------------- MOV AL,9 ;Interrupt number MOV DI,OFFSET OLD_INT_9 ;Store vector here MOV DX,OFFSET INT_9 ;New interrupt procedure CALL SET_INT ;Make change MOV AL,16H MOV DI,OFFSET OLD_INT_16 MOV DX,OFFSET INT_16 CALL SET_INT MOV AL,21H MOV DI,OFFSET OLD_INT_21 MOV DX,OFFSET INT_21 CALL SET_INT ;---------------------------------------------------------------------- ; Deallocate the copy of the environment loaded with the program. ; Establish memory residency and terminate. ;---------------------------------------------------------------------- MOV AX,WORD PTR DS:[2CH] ;Address of environment MOV ES,AX ;In ES register MOV AH,49H ;Release allocated memory INT 21H ;Thru DOS MOV DX,OFFSET LAST_BYTE - OFFSET CSEG + 15 ADD DX,DTA_SIZE ;Total size in bytes MOV CL,4 ; /16 = SHR DX,CL ;In paras MOV AX,3100H ;Keep (TSR) INT 21H ;Thru DOS INITIALIZE ENDP ;====================================================================== ; Check for the correct version of DOS. Return if 2.0 or later. ; Terminate if 1.x. AX destroyed on return. ;---------------------------------------------------------------------- BAD_DOS_MSG DB "SlashBar: Requires DOS 2.0+",CR,LF,"$" CHECK_VERSION PROC NEAR ASSUME CS:CSEG, DS:CSEG, ES:CSEG, SS:CSEG MOV AH,30H ;Get DOS version number fn INT 21H ;Thru DOS ;AL=major ver #,AH=minor ver # CMP AL,02 ;Compare to 2.0 JAE VER_OK ;If 2.0 or later, go on. MOV DX,OFFSET BAD_DOS_MSG ;DS:DX is message MOV AH,9 ;Display string fn INT 21H ;Thru DOS INT 20H ;Exit 1.0 style VER_OK: RET CHECK_VERSION ENDP ;====================================================================== ; Get/Save/Set the interrupt vector. AL contains vector number. ; ES:DI points to DWORD destination for old address. ; DS:DX points to new interrupt address. AX destroyed. ;---------------------------------------------------------------------- SET_INT PROC NEAR ASSUME CS:CSEG, DS:CSEG, ES:CSEG, SS:CSEG PUSH ES PUSH AX ;Save vector # in AL MOV AH,35H ;Get address function INT 21H ;Thru DOS MOV WORD PTR [DI+0],BX ;Save address in ES:DI MOV WORD PTR [DI+2],ES POP AX ;Get AL back MOV AH,25H ;Set new address to DS:DX INT 21H ;Thru DOS POP ES RET SET_INT ENDP ;====================================================================== ; Data here is allocated after the program loads into memory to save space ; in the COM file so the basic listing will be smaller. ; PC variable used to keep track of relative addresses. ;---------------------------------------------------------------------- PC = $ ;Set imaginary counter SCREEN_BUF = PC ;DB NROW*NCOL*2 DUP(?) PC = PC + NROW * NCOL * 2 KEYS = PC ;DW 256 DUP(0) PC = PC + 256 * 2 ;For buffered input INKEY_BUF = PC ;DW 76 DUP(0) PC = PC + 76 * 2 KEY_STK = PC ;DW 32 DUP(0) PC = PC + 32 * 2 MENU_STK = PC ;DW 32 DUP(0) PC = PC + 32 * 2 FILE_DTA = PC LAST_BYTE = PC CSEG ENDS END ENTPT