16-Jul-86 14:08:30-PDT,9473;000000000001 Return-Path: Received: FROM CU20B.COLUMBIA.EDU BY B.ISI.EDU WITH TCP ; 16 Jul 86 14:04:53 PDT Date: Wed 16 Jul 86 15:41:15-EDT From: Frank da Cruz Subject: SCRNCOLR.ASM To: info-ibmpc@B.ISI.EDU Message-ID: <12223203329.166.SY.FDC@CU20B.COLUMBIA.EDU> Here's a version of SCRNCOLR.ASM that, unlike the version in your library, will assemble and run. page 64,132 title scrncolr - Change display screen from white to color attrib .radix 10 ;*************************************************************** ; Adapted from "SCREEN.ASM" by H. Fischer - HFischer@eclb 12/83 ; SCREEN was Typed in by Glass - gjg@cmu-cs-cad from Byte Nov. 1983 ; ; NOTE: only meaningful with color card, and does not look at ; keyboard (which makes it easywriter, etc. compatible) ; ; To build this program: ; 1> masm scrncolr; /* assemble the code */ ; 2> link scrncolr; /* link it - will get no stack seg. message */ ; 3> exe2bin scrncolr.exe scrncolr.com /* make executable */ ; 4> del scrncolr.exe /* don't need this anymore */ ; ; To use program: run it or place in autoexec.bat as follows: ; ; scrncolr nn rr ; ; where nn are screen attributes to replace ; normal white (attr=07h) video, and rr are ; attributes for reversed white (attr=70h) ; (intensity and blink are preserved). ; ; for example, to change calls for white to white on blue ; and to change calls for reverse white to magenta on white, ; issue the call: "scrncolr 17 75" ; ; Only 80x25 screen calls are affected and only in text mode, ; (this makes it LOGO and APL compatible) ; ; COMMANDS: ; none -- you reassemble to change the color assignment ;*************************************************************** ; ; Define interrupt vectors for ; screen interrupt 10H, in segment 0. ; ;*************************************************************** scrvect segment at 0 ; define screen interrupt vector org 10h*4 SCRINT label word ; fixed. was dword. [jrd] scrvect ends ;*************************************************************** ; ; define constants ; ;*************************************************************** bw_val equ 07h ; standard b&w attibute sent to monitor ;*************************************************************** ; ; start code area ; ;*************************************************************** code segment para assume cs:code org 82h ; parameters PARM label word ; normal & rev attribs "nn rr" org 100h ; start code offset 100h from starting segment ; (this leaves room for DOS's work areas) KEY proc far START: ; Initialization code...used only once, on system startup jmp init_code ; call initialization routine even validchk db 'FCP!' ; used by INSTALL to check for valid SCREEN ; program ;*************************************************************** ; ; SCR_RTNE - Replaces SCREEN interrupt so that it can intercept ; B&W character writes and change attributes ; ;*************************************************************** SCR_RTNE: assume ds:code sti push ds ; get cs into ds the funny way push cs pop ds cmp ah,0 ; Spot mode change call jne NOT_MODE mov savemod,al ; Save mode input NOT_MODE: cmp ah,6 ; Spot SCROLL UP and SCROLL DOWN calls jl NORMAL_SCR ; push ax ; check if in 80x25 modes mov al,savemod cmp al,2 pop ax jl NORMAL_SCR ; no-ignore attribs (keep LOGO straight) push ax ; check if in 80x25 modes mov al,savemod cmp al,3 pop ax jg NORMAL_SCR ; no-ignore attribs (keep LOGO straight) cmp ah,6 jg NOT_SCROLL ; SCROLL: call GET_CH ; for scrolling, update attribute jmp NORMAL_SCR ; now, execute scroll NOT_SCROLL: cmp ah,9 ; check for "WRITE ATTRIBUTE/CHAR" cmd jne NORMAL_SCR ; send out any other command as normal xchg bh,bl ; get attribute for command call GET_CH ; update attribute for command xchg bh,bl ; move attribute back to bh for cmd NORMAL_SCR: pop ds ; restore ds reg ; ; NOTE: We are now ready to invoke the BIOS screen interrupt. ; Since the ROM code includes an IRET interrupt return call, ; all we need to do is to jump to the start of the ROM code ; and all will be well. Since the initialization code set ; up the address to the screen interrupt code below, we can ; set up a forced jump to that address. JMP_SCR: ; Address to SCREEN interrupt db 0EAh ; force a FAR JMP but do not set up dest- dw 0,0 ; ination address at assembly time. ; (INIT routine will set this address) savemod db 3 ; default to 80x24 color mode KEY endp ;done with main routine ;*************************************************************** ; ; GET_CH - subroutine replaces B&W character with current replacement ; attributes and allows for intensity bit setting ; ; Inputs : bh contains attribute to be modified ; ;*************************************************************** GET_CH proc near mov savech,bh ; save character and bh,77h ; Remove intensity and blink bits cmp bh,07h ; see if currently defined B&W value jne ISITREV ; exit if not mov bh,savech ; otherwise, modify to current attribute and bh,88h ; get rid of B&W part or bh,normvid ; move in current attribute part jmp OUT ISITREV: cmp bh,70h ; see if currently defined W&B value mov bh,savech ; otherwise, modify to current attribute jne OUT and bh,88h or bh,revrvid OUT: ret ; done savech db 0 ; temporary character store normvid db 05h ; replacement for white norml video revrvid db 50h ; replacement for reverse white video GET_CH endp LASTONE: ; all code after this label is freed to DOS use after ; initialization of the program. ;*************************************************************** ; ; INIT_CODE - Code to load and initialize the SCREEN program.. ; sets up DOS to keep all code before "LASTONE" label ; safe from overlaying during system operation. ; ;*************************************************************** INIT_CODE proc near ; initialize SCREEN intercept code assume es:scrvect ;'vectors' is interrupt segment 0 mov ax,scrvect ; get address to interrupt vector mov es,ax ; save in es mov ax,es:scrint ; get address to interrupt mov bx,offset jmp_scr+1 ; address to place to save vector mov [bx],ax ; save interrupt address mov ax,es:scrint[2] ; get interrupt segment for rtne mov [bx+2],ax ; save it too mov es:scrint,offset scr_rtne ; now replace with own address mov ax,cs ; save segment in interrupt vector mov es:scrint[2],ax ; mov ax,cs ; make parameters for color mov ds,ax ; addressable mov dx,PARM test dx,0040h ; fix hex a-f jz IT2 sub dx,0007h IT2: test dx,4000h jz IT3 sub dx,0700h IT3: and dx,0f0fh ; strip and jamb nibbles mov cl,4 shl dl,cl or dh,dl mov normvid,dh ; save parameter mov dx,PARM+3 test dx,0040h ; fix hex a-f jz IT4 sub dx,0007h IT4: test dx,4000h jz IT5 sub dx,0700h IT5: and dx,0f0fh mov cl,4 shl dl,cl or dh,dl mov revrvid,dh mov dx,offset lastone ; save all code up to "LASTONE" label int 27h ; no return needed INIT_CODE endp code ends end start -------