Use backtick code blocks for syntax highlighting

This commit is contained in:
James Gregory 2013-12-31 11:38:48 +11:00
commit f658bfbb40
203 changed files with 26546 additions and 25801 deletions

436
25-05.md
View file

@ -12,114 +12,116 @@ pages: 474-478
**LISTING 25.3 L25-3.ASM**
; Program to illustrate operation of set/reset circuitry to force
; setting of memory that already contains data.
; By Michael Abrash.
;
stack segment para stack ‘STACK#146;
db 512 dup(?)
stack ends
;
EGA_VIDEO_SEGMENT equ 0a000h ;EGA display memory segment
;
; EGA register equates.
;
SC_INDEX equ 3c4h ;SC index register
SC_MAP_MASK equ 2 ;SC map mask register
GC_INDEX equ 3ceh ;GC index register
GC_SET_RESET equ 0 ;GC set/reset register
GC_ENABLE_SET_RESET equ 1 ;GC enable set/reset register
;
; Macro to set indexed register INDEX of SC chip to SETTING.
;
SETSC macro INDEX, SETTING
mov dx,SC_INDEX
mov al,INDEX
out dx,al
inc dx
mov al,SETTING
out dx,al
dec dx
endm
;
; Macro to set indexed register INDEX of GC chip to SETTING.
;
SETGC macro INDEX, SETTING
mov dx,GC_INDEX
mov al,INDEX
out dx,al
inc dx
mov al,SETTING
out dx,al
dec dx
endm
;
cseg segment para public ‘CODE#146;
assume cs:cseg
start proc near
;
; Select 640x480 graphics mode.
;
mov ax,012h
int 10h
;
mov ax,EGA_VIDEO_SEGMENT
mov es,ax ;point to video memory
;
; Draw 24 10-scan-line high horizontal bars in green, 10 scan lines apart.
;
SETSC SC_MAP_MASK,02h ;map mask setting enables only
; plane 1, the green plane
sub di,di ;start at beginning of video memory
mov al,0ffh
mov bp,24 ;# bars to draw
HorzBarLoop:
mov cx,80*10 ;# bytes per horizontal bar
rep stosb ;draw bar
add di,80*10 ;point to start of next bar
dec bp
jnz HorzBarLoop
;
; Fill screen with blue, using set/reset to force plane 0 to 1#146;s and all
; other plane to 0#146;s.
;
SETSC SC_MAP_MASK,0fh ;must set map mask to enable all
; planes, so set/reset values can
; be written to memory
SETGC GC_ENABLE_SET_RESET,0fh ;CPU data to all planes will be
; replaced by set/reset value
SETGC GC_SET_RESET,01h ;set/reset value is 0ffh for plane 0
; (the blue plane) and 0 for other
; planes
sub di,di
mov cx,80*480 ;# bytes per screen
mov al,0ffh ;since set/reset is enabled for all
; planes, the CPU data is ignored-
; only the act of writing is
; important
rep stosb ;perform fill (affects all planes)
;
; Turn off set/reset.
;
SETGC GC_ENABLE_SET_RESET,0
;
; Wait for a keystroke.
;
mov ah,1
int 21h
;
; Restore text mode.
;
mov ax,03h
int 10h
;
; Exit to DOS.
;
mov ah,4ch
int 21h
start endp
cseg ends
end start
```nasm
; Program to illustrate operation of set/reset circuitry to force
; setting of memory that already contains data.
; By Michael Abrash.
;
stack segment para stack ‘STACK#146;
db 512 dup(?)
stack ends
;
EGA_VIDEO_SEGMENT equ 0a000h ;EGA display memory segment
;
; EGA register equates.
;
SC_INDEX equ 3c4h ;SC index register
SC_MAP_MASK equ 2 ;SC map mask register
GC_INDEX equ 3ceh ;GC index register
GC_SET_RESET equ 0 ;GC set/reset register
GC_ENABLE_SET_RESET equ 1 ;GC enable set/reset register
;
; Macro to set indexed register INDEX of SC chip to SETTING.
;
SETSC macro INDEX, SETTING
mov dx,SC_INDEX
mov al,INDEX
out dx,al
inc dx
mov al,SETTING
out dx,al
dec dx
endm
;
; Macro to set indexed register INDEX of GC chip to SETTING.
;
SETGC macro INDEX, SETTING
mov dx,GC_INDEX
mov al,INDEX
out dx,al
inc dx
mov al,SETTING
out dx,al
dec dx
endm
;
cseg segment para public ‘CODE#146;
assume cs:cseg
start proc near
;
; Select 640x480 graphics mode.
;
mov ax,012h
int 10h
;
mov ax,EGA_VIDEO_SEGMENT
mov es,ax ;point to video memory
;
; Draw 24 10-scan-line high horizontal bars in green, 10 scan lines apart.
;
SETSC SC_MAP_MASK,02h ;map mask setting enables only
; plane 1, the green plane
sub di,di ;start at beginning of video memory
mov al,0ffh
mov bp,24 ;# bars to draw
HorzBarLoop:
mov cx,80*10 ;# bytes per horizontal bar
rep stosb ;draw bar
add di,80*10 ;point to start of next bar
dec bp
jnz HorzBarLoop
;
; Fill screen with blue, using set/reset to force plane 0 to 1#146;s and all
; other plane to 0#146;s.
;
SETSC SC_MAP_MASK,0fh ;must set map mask to enable all
; planes, so set/reset values can
; be written to memory
SETGC GC_ENABLE_SET_RESET,0fh ;CPU data to all planes will be
; replaced by set/reset value
SETGC GC_SET_RESET,01h ;set/reset value is 0ffh for plane 0
; (the blue plane) and 0 for other
; planes
sub di,di
mov cx,80*480 ;# bytes per screen
mov al,0ffh ;since set/reset is enabled for all
; planes, the CPU data is ignored-
; only the act of writing is
; important
rep stosb ;perform fill (affects all planes)
;
; Turn off set/reset.
;
SETGC GC_ENABLE_SET_RESET,0
;
; Wait for a keystroke.
;
mov ah,1
int 21h
;
; Restore text mode.
;
mov ax,03h
int 10h
;
; Exit to DOS.
;
mov ah,4ch
int 21h
start endp
cseg ends
end start
```
#### Manipulating Planes Individually {#Heading7}
@ -142,111 +144,113 @@ be used to control individual pixels.
**LISTING 25.4 L25-4.ASM**
; Program to illustrate operation of set/reset circuitry in conjunction
; with CPU data to modify setting of memory that already contains data.
; By Michael Abrash.
;
stack segment para stack ‘STACK#146;
db 512 dup(?)
stack ends
;
EGA_VIDEO_SEGMENT equ 0a000h ;EGA display memory segment
;
; EGA register equates.
;
SC_INDEX equ 3c4h ;SC index register
SC_MAP_MASK equ 2 ;SC map mask register
GC_INDEX equ 3ceh ;GC index register
GC_SET_RESET equ 0 ;GC set/reset register
GC_ENABLE_SET_RESET equ 1 ;GC enable set/reset register
;
; Macro to set indexed register INDEX of SC chip to SETTING.
;
SETSC macro INDEX, SETTING
mov dx,SC_INDEX
mov al,INDEX
out dx,al
inc dx
mov al,SETTING
out dx,al
dec dx
endm
;
; Macro to set indexed register INDEX of GC chip to SETTING.
;
SETGC macro INDEX, SETTING
mov dx,GC_INDEX
mov al,INDEX
out dx,al
inc dx
mov al,SETTING
out dx,al
dec dx
endm
;
cseg segment para public ‘CODE#146;
assume cs:cseg
start proc near
;
; Select 640x350 graphics mode.
;
mov ax,010h
int 10h
;
mov ax,EGA_VIDEO_SEGMENT
mov es,ax ;point to video memory
;
; Draw 18 10-scan-line high horizontal bars in green, 10 scan lines apart.
;
SETSC SC_MAP_MASK,02h;map mask setting enables only
; plane 1, the green plane
sub di,di;start at beginning of video memory
mov al,0ffh
mov bp,18;# bars to draw
HorzBarLoop:
mov cx,80*10;# bytes per horizontal bar
rep stosb;draw bar
add di,80*10;point to start of next bar
dec bp
jnz HorzBarLoop
;
; Fill screen with alternating bars of red and brown, using CPU data
; to set plane 1 and set/reset to set planes 0, 2 & 3.
;
SETSC SC_MAP_MASK,0fh ;must set map mask to enable all
; planes, so set/reset values can
; be written to planes 0, 2 & 3
; and CPU data can be written to
; plane 1 (the green plane)
SETGC GC_ENABLE_SET_RESET,0dh ;CPU data to planes 0, 2 & 3 will be
; replaced by set/reset value
SETGC GC_SET_RESET,04h ;set/reset value is 0ffh for plane 2
; (the red plane) and 0 for other
; planes
sub di,di
mov cx,80*350/2 ;# words per screen
mov ax,07e0h ;CPU data controls only plane 1;
; set/reset controls other planes
rep stosw ;perform fill (affects all planes)
;
; Turn off set/reset.
;
SETGC GC_ENABLE_SET_RESET,0
;
; Wait for a keystroke.
;
mov ah,1
int 21h
;
; Restore text mode.
;
mov ax,03h
int 10h
;
; Exit to DOS.
;
mov ah,4ch
int 21h
start endp
cseg ends
end start
```nasm
; Program to illustrate operation of set/reset circuitry in conjunction
; with CPU data to modify setting of memory that already contains data.
; By Michael Abrash.
;
stack segment para stack ‘STACK#146;
db 512 dup(?)
stack ends
;
EGA_VIDEO_SEGMENT equ 0a000h ;EGA display memory segment
;
; EGA register equates.
;
SC_INDEX equ 3c4h ;SC index register
SC_MAP_MASK equ 2 ;SC map mask register
GC_INDEX equ 3ceh ;GC index register
GC_SET_RESET equ 0 ;GC set/reset register
GC_ENABLE_SET_RESET equ 1 ;GC enable set/reset register
;
; Macro to set indexed register INDEX of SC chip to SETTING.
;
SETSC macro INDEX, SETTING
mov dx,SC_INDEX
mov al,INDEX
out dx,al
inc dx
mov al,SETTING
out dx,al
dec dx
endm
;
; Macro to set indexed register INDEX of GC chip to SETTING.
;
SETGC macro INDEX, SETTING
mov dx,GC_INDEX
mov al,INDEX
out dx,al
inc dx
mov al,SETTING
out dx,al
dec dx
endm
;
cseg segment para public ‘CODE#146;
assume cs:cseg
start proc near
;
; Select 640x350 graphics mode.
;
mov ax,010h
int 10h
;
mov ax,EGA_VIDEO_SEGMENT
mov es,ax ;point to video memory
;
; Draw 18 10-scan-line high horizontal bars in green, 10 scan lines apart.
;
SETSC SC_MAP_MASK,02h;map mask setting enables only
; plane 1, the green plane
sub di,di;start at beginning of video memory
mov al,0ffh
mov bp,18;# bars to draw
HorzBarLoop:
mov cx,80*10;# bytes per horizontal bar
rep stosb;draw bar
add di,80*10;point to start of next bar
dec bp
jnz HorzBarLoop
;
; Fill screen with alternating bars of red and brown, using CPU data
; to set plane 1 and set/reset to set planes 0, 2 & 3.
;
SETSC SC_MAP_MASK,0fh ;must set map mask to enable all
; planes, so set/reset values can
; be written to planes 0, 2 & 3
; and CPU data can be written to
; plane 1 (the green plane)
SETGC GC_ENABLE_SET_RESET,0dh ;CPU data to planes 0, 2 & 3 will be
; replaced by set/reset value
SETGC GC_SET_RESET,04h ;set/reset value is 0ffh for plane 2
; (the red plane) and 0 for other
; planes
sub di,di
mov cx,80*350/2 ;# words per screen
mov ax,07e0h ;CPU data controls only plane 1;
; set/reset controls other planes
rep stosw ;perform fill (affects all planes)
;
; Turn off set/reset.
;
SETGC GC_ENABLE_SET_RESET,0
;
; Wait for a keystroke.
;
mov ah,1
int 21h
;
; Restore text mode.
;
mov ax,03h
int 10h
;
; Exit to DOS.
;
mov ah,4ch
int 21h
start endp
cseg ends
end start
```