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CD ROM Paradise Collection 4
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CD ROM Paradise Collection 4 1995 Nov.iso
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graphics
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motionrd.zip
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README.ASM
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Assembly Source File
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1994-12-04
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12KB
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319 lines
; Smooth vertical scroller by Patch - hamell@cs.pdx.edu
; Made for the intro Motion by Avalanche
; Done sometime in December 1993
;
; If you use this code in any manner, please inform me.
;
; If you want to be cool, modify this so the number of lines can be unlimited.
; If you do so, please email me the new source code.
.model small
.stack 1024
.386
.data
linecount db 0
screen_offs dw 160
include status.inc
include motion-a.inc
.code
TOPSCREENOFFS EQU 160
LINECOMPAREVAL EQU 367
VIEWLINES EQU 23
PIXELSTEP EQU 2
NUMSTEPS EQU 14/PIXELSTEP
include key.inc
WaitVRetrace MACRO
LOCAL VRetrace,NoVRetrace
mov dx,03dah
VRetrace: in al,dx
test al,00001000b
jnz VRetrace
NoVRetrace: in al,dx
test al,00001000b
jz NoVRetrace
ENDM
WaitVActive MACRO
LOCAL VActive
mov dx,03dah
VActive: in al,dx
test al,00001000b
jnz VActive
ENDM
WaitVInactive MACRO
LOCAL VInactive
mov dx,03dah
VInactive: in al,dx
test al,00001000b
jz VInactive
ENDM
WaitHRetrace MACRO
LOCAL HRetrace,NoHRetrace
mov dx,03dah
HRetrace: in al,dx
test al,00000001b
jnz HRetrace
NoHRetrace: in al,dx
test al,00000001b
jz NoHRetrace
ENDM
WaitHActive MACRO
LOCAL HActive
mov dx,03dah
HActive: in al,dx
test al,00000001b
jnz HActive
ENDM
WaitHInactive MACRO
LOCAL HInactive
mov dx,03dah
HInactive: in al,dx
test al,00000001b
jz HInactive
ENDM
Set_Start_Addr MACRO
mov bx,[screen_offs] ; set starting address
mov dx,03d4h
mov al,0ch
mov ah,bh
out dx,ax
inc al
mov ah,bl
out dx,ax
ENDM
start: mov ax,@data
mov ds,ax
call _Set_New_Int9
mov ax,0003h
int 10h
mov ax,0100h ; hide the cursor
mov cx,0800h
int 10h
WaitVRetrace
push LINECOMPAREVAL
call _Set_Line_Compare
add sp,2
Set_Start_Addr
WaitVRetrace
cld
mov ax,0b800h ; dump status bar to screen
mov es,ax
xor di,di
mov si,offset STATUSBAR
mov cx,STATUSBAR_LEN
rep movsw
mov di,[screen_offs] ; dump ansi to screen
shl di,1 ; *2, each offset is 2 bytes
mov si,offset ANSI_SCREEN
; add si,160
mov cx,ANSI_DEPTH*80
rep movsw
get_key:
; cmp cs:[_keynumpress],0
; je get_key
cmp cs:_keys[kUARROW],1 ; cursor up?
je key_up
cmp cs:_keys[kKEYPAD8],1 ; cursur up?
je key_up
cmp cs:_keys[kDARROW],1 ; cursor down?
je key_down
cmp cs:_keys[kKEYPAD2],1 ; cursor down?
je key_down
cmp cs:_keys[kHOME],1 ; home?
je key_home
cmp cs:_keys[kEND],1 ; end?
je key_end
cmp cs:_keys[kPGUP],1 ; pgup?
je key_pgup
cmp cs:_keys[kPGDN],1 ; pgdn?
je key_pgdn
cmp cs:_keys[kESC],1 ; esc?
je exit
jmp get_key
key_up: cmp [linecount],0 ; at top?
je get_key ; if so, jump
dec [linecount]
sub [screen_offs],80 ; one line up
WaitVRetrace
Set_Start_Addr
mov bx,1008h ; start at char line 14
mov cx,NUMSTEPS
pan_up: WaitVInactive
WaitHActive
sub bh,PIXELSTEP ; next line of char
mov dx,03d4h
mov ax,bx
out dx,ax
dec cx
jnz pan_up
WaitVInactive
WaitHActive
mov dx,03d4h
mov ax,0008h ; set char line to 0
out dx,ax
jmp get_key
key_down: cmp [linecount],ANSI_DEPTH-VIEWLINES
je get_key
inc [linecount]
add [screen_offs],80
mov bx,0008h ; start at char line 0
mov cx,NUMSTEPS
pan_down: WaitVInactive
WaitHActive
add bh,PIXELSTEP ; next char line
mov dx,03d4h
mov ax,bx
out dx,ax
dec cx
jnz pan_down
WaitVRetrace
Set_Start_Addr
WaitVInactive
WaitHActive
mov dx,03d4h
mov ax,0008h ; set char line to 0
out dx,ax
jmp get_key
key_home: cmp [linecount],0
je get_key
mov [linecount],0
mov [screen_offs],TOPSCREENOFFS
WaitVRetrace
Set_Start_Addr
jmp get_key
key_end: cmp [linecount],ANSI_DEPTH-VIEWLINES
je get_key
mov [linecount],ANSI_DEPTH-VIEWLINES
mov [screen_offs],(ANSI_DEPTH-VIEWLINES)*80
add [screen_offs],TOPSCREENOFFS
WaitVRetrace
Set_Start_Addr
jmp get_key
key_pgup: cmp [linecount],0 ; at top line?
je get_key
cmp [linecount],24 ; full screen left to view?
jbe key_home ; if not, jump
sub [linecount],VIEWLINES
sub [screen_offs],80*VIEWLINES
WaitVActive
Set_Start_Addr
mov cx,8
pan_pgup: WaitVRetrace
dec cx
jnz pan_pgup
jmp get_key
key_pgdn: cmp [linecount],ANSI_DEPTH-VIEWLINES ; at bottom line?
je get_key
cmp [linecount],ANSI_DEPTH+1-VIEWLINES*2
; full screen to view?
jae key_end ; if not, jump
add [linecount],VIEWLINES
add [screen_offs],80*VIEWLINES
WaitVRetrace
Set_Start_Addr
mov cx,8
pan_pgdn: WaitVRetrace
dec cx
jnz pan_pgdn
jmp get_key
exit: call _Set_Old_Int9
mov ax,0003h ; text mode 3
int 10h
mov ax,4c00h ; exit
int 21h
;******************************************************************************
;* PROC : void Set_Line_Compare(word rasterline);
;* Purpose : Sets the line compare
;* The area above the line compare is the segment and offset where
;* the start address is set to.
;* The area below the line compare is at A000:0000.
;* Entrance: rasterline - the raster line to set for line compare
;* for every pixel line, there are 2 raster lines
;* so pixel line 100 is raster line 200
;* Exit : nothing
;******************************************************************************
_Set_Line_Compare PROC NEAR
push bp
mov bp,sp
mov bx,[bp + 4] ; BX = line value
mov dx,03d4h ; CRTC reg
mov al,09h ; 09h = max scan line index
out dx,al ; 10th bit of line compare
inc dl ; goes in bit 6 of the index
in al,dx ; read in previous contents
mov ah,bh ; get bit 10 of line compare
or ah,11111101b ; make other bits 1 as a mask
ror ah,03h ; move to bit 6
and al,ah ; AND them together
out dx,al
dec dl ; 03d4h
mov al,07h ; 07h = overflow index
out dx,al ; 9th bit of line compare
inc dl ; goes in bit 4 of the index
in al,dx ; read in previous contents
mov ah,bh ; get bit 9 of line compare
or ah,11111110b ; make other bits 1 as a mask
rol ah,04h ; move to bit 4
and al,ah ; AND them together
out dx,al
dec dl ; 03d4h
mov al,18h ; 18h = line compare index
mov ah,bl ; AH = lower 8 bits
out dx,ax
pop bp
ret
_Set_Line_Compare ENDP
END start
