Power Programmierung 2

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/ Power Programmierung 2 / Power-Programmierung CD 2 (Tewi)(1994).iso / c / library / dos / diverses / cexpress / turbobug.asm < prev next >

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Assembly Source File | 1990-09-15 | 22.0 KB | 441 lines

cseg segment org 100h assume cs:cseg, ds:cseg buffer equ 0B000h ;address of video buffer (presently monochrome) int_num equ 80h ;1st INT of consecutive series of five begin: jmp set_up tag1 db 'S T A',26,'C K ' tag2 db ' VAR',26 bottom db ' AX BX CX DX SI DI BP SP DS ES ' msg db 'TURBOBUG loaded',0AH,0DH,'$' ;---NOTE: no provision for retrace synchronization -- causes a blizzard on CGA ;---ROUTINE THAT DRAWS THE STACK BEGINS HERE: stack: sti ;enable interrupts pushf ;save flags push ds ;save all changed registers push es ; push di ; push si ; push ax ; push bx ; push cx ; push dx ; push cs ;to get at variables (above) place pop ds ; code segment value in DS mov ax,buffer ;point ES to video buffer mov es,ax ; cld ;set direction flag ;---DRAW "STACK" LABEL ON TOP LEFT OF SCREEN: mov ah,112 ;use reverse image lea si,tag1 ;point to the data string mov cx,5 ;extends over five rows mov di,0 ;ES:DI points to top left of screen L1: lodsb ;get a character stosw ;write it, with attribute lodsb ;get next character stosw ;write it to the right of the former add di,156 ;point to next row loop L1 ;repeat ;---WRITE OUT THE STACK CONTENTS AND HEX EQUIVALENTS: mov cx,78 ;78 columns available mov di,324 ;point to 3rd col from left on 3rd row push bp ;will use BP as stack pointer mov bp,0FFFFH ;point to top of stack L2: mov ah,112 ;drawn in reverse image mov al,[bp] ;get a byte from the stack dec bp ;point to byte below for next time stosw ;write the byte in reverse image sub ah,ah ;byte in AL, clear AH shl ax,1 ;move top half of byte into AH shl ax,1 ; shl ax,1 ; shl ax,1 ; shr al,1 ;move bottom half back to bottom of AL shr al,1 ; shr al,1 ; shr al,1 ; cmp al,9 ;low nibble first: is it a numeral? jb L3 ;if so, jump ahead add al,55 ;else is A - F, add 55 to get ASCII code jmp short L4 ;go write it L3: add al,48 ;add 48 to get ASCII code for numeral L4: mov es:[di+318],al ;write it cmp ah,9 ;high nibble next: is it a numeral? jb L5 ;repeat same process as above add ah,55 ; jmp short L6 ; L5: add ah,48 ; L6: mov es:[di+158],ah ; loop L2 ; pop bp ;restore BP ;---PLOT BP POSITION: mov ax,bp ;BP value to AX neg ax ;NEG gives distance from top of stack mov bh,0 ;BH=0 flags that no scale drawn to right of BP mov dl,100 ;divide distance by 100 div dl ; cmp al,0 ;less than 100? ja L8 ;if not, no BP label is written cmp ah,78 ;less than or equal to 78? (available space) ja L8 ;if not, no label je L7 ;BP on last col, don't set flag for right scale mov bh,1 ;no jump, flag that chars later drawn to right ;---WRITE "BP" IF BP IS ON THE SCALE: L7: push ax ;save distance to BP shl ah,1 ;double it to calculate video buffer position inc ah ;plus two more, since offsets are from BP=0 inc ah ; mov al,ah ;transfer value to AL sub ah,ah ;extend through AX mov di,ax ;add value to buffer pointer mov ah,112 ;use reverse image mov al,'B' ;prepare to write the 'B' stosw ;write it add di,158 ;shift to character cell below mov al,'P' ;prepare to write the 'P' stosw ;write it pop ax ;restore distance to BP ;---CALCULATE AND WRITE SCALE FROM LEFT UP TO BP: sub cx,cx ;clear cx for counter mov cl,ah ;distance to BP dec cl ;minus 1 = number of chars to write mov ax,cx ;copy in AX push ax ;use later to calc chars to right jmp short L9 ;go make the division ;---CASE WHERE BP IS OFF THE SCALE: L8: mov bh,0 ;flag that no chars to right mov cx,78 ;BP off scale, write 78 chars mov al,ah ;move to AL the distance to BP dec al ;minus 1 to adjust for offset from 0 sub ah,ah ;extend through AX push ax ;pseudo-PUSH, since other cases use it ;---WRITE SCALE TO LEFT OF BP: L9: mov di,164 ;pointer to first char mov dl,10 ;will divide by 10 for top line of scale div dl ;now ten's place in AL, one's place in AH add ah,48 ;add 48 to get the ASCII char equivalent inc ah ;INC to compensate for first DEC below add al,48 ;add 48 to get ASCII char equivalent L10: dec ah ;in loop, decrement 1's place digit cmp ah,'0' ;gotten to 0? ja L12 ;if not, no 10's place printed, jump ahead jb L11 ;if below '0', reset to '9' mov es:[di-160],al ;1's place is '0', so print 10's place char dec al ;decrement tens counter cmp al,'0' ;below '0'yet? jae L12 ;if not, jump ahead mov al,'9' ;else, reset to '9' jmp short L12 ;jump ahead L11: mov ah,'9' ;this line used when 1's place is reset L12: mov es:[di],ah ;print 1's place digit inc di ;point 2 bytes ahead in the video buffer inc di ; loop L10 ;go do next char(s) of the scale ;---DRAW SCALE TO RIGHT OF BP (IF REQUIRED): pop ax ;number chars to left cmp bh,0 ;test flag whether any chars je L16 ;if not, jump ahead and quit mov cx,77 ;max number of chars to draw (78 - 1 for bp) sub cx,ax ;subtract number chars drawn on left add ax,5 ;adjust for extra chars on left shl ax,1 ;double the number for video buffer position mov di,156 ;start of line position in buffer add di,ax ;add the offset mov al,'1' ;start counting from 1 mov ah,al ;ten's place also starts from 1 L13: mov es:[di],al ;loop: write a 1's place character inc di ;point to next buffer position inc di ; cmp al,'0' ;test whether 1's place has gotten to 0 jne L14 ;if not, jump ahead mov es:[di-162],ah ;if so, write a ten's place character inc ah ;inc ten's place counter L14: inc al ;inc one's place counter cmp al,':' ;test if one's place has surpassed '9' jb L15 ;if not, jump ahead mov al,'0' ;else, reset one's place counter to '0' L15: loop L13 ;go write next character(s) L16: pop dx ;done! pop cx ; pop bx ; pop ax ; pop si ; pop di ; pop es ; pop ds ; popf ;restore flags iret ;return from the DISPLAY STACK interrupt ;-------------------------Display Memory Variable--------------------------- ;---ON ENTRY, bx HOLDS OFFSET FROM bp OF VAR ADDRESS ON STACK ;---THE CALLING CODE MUST SAVE PRIOR CONTENTS OF bx IF THEY ARE REQUIRED var: sti ;enable hardware interrupts pushf ;save flags push ds ;save all changed registers push es ; push ax ; push cx ; push di ; push si ; cld ;set direction flag ;---WRITE THE 'VAR' LABEL: push cs ;set DS to CS value... pop ds ;...in order to access TAG2 mov ax,buffer ;point ES to monochrome buffer mov es,ax ; mov di,800 ;point to 6th row of screen lea si,tag2 ;DS:SI points to 'VAR' string mov cx,6 ;these are six characters mov ah,112 ;write them in reverse image B1: lodsb ;get a character stosw ;write it loop B1 ;go do next ;---NOW WRITE OUT THE MEMORY CONTENTS: mov cx,74 ;number of cols available on the line add bx,bp ;add BP value to the offset from BP mov ax,ss:[bx+2] ;get segment address of var mov ds,ax ;place in DS mov si,ss:[bx] ;place offset of var in SI mov ah,15 ;write in intensified attribute B2: lodsb ;get a char stosw ;write it, setting the new attribute loop B2 ;go do next char pop si ;done! restore changed registers pop di ; pop cx ; pop ax ; pop es ; pop ds ; popf ;restore flags iret ;return from the DISPLAY VARIABLE interrupt ;-------------------------Register Display Routine-------------------------- ;---THIS PROCEDURE WRITES OUT AX CONTENTS AS CHARS AND IN HEX: hexwrite proc near push bx ;save changed registers push ds ; push ax ;point DS to BIOS data area mov ax,40h ; mov ds,ax ; pop ax ; mov bh,4 ;test if ctrl key down test ds:[17h],bh ; mov bx,ax ;copy input reg in case jump taken jnz C2 ;go make hex write if ctrl down cmp ah,es:[di-156] ;test if high char is same as before jne C2 ;if not, go write hex equivalent cmp ah,32 ;is it a space char? jne C1 ;if not, will definitely not write in hex, jump cmp es:[di-160],ah ;if spc, chk line above. Will be 32 if first je C2 ; call on cleared screen, else FF from scroll C1: add di,4 ;not writing in hex, set buffer pointer ahead jmp short C7 ;jump ahead ;---WRITE THE HIGH BYTE IN HEX: C2: shr ax,1 ;shift AH halfway down into AL shr ax,1 ; shr ax,1 ; shr ax,1 ; shr al,1 ;shift AL nibble rest of the way down shr al,1 ; shr al,1 ; shr al,1 ;now high nibble in AH, low nibble in AL cmp ah,9 ;is high nibble a numeral? ja C3 ;if not, jump ahead add ah,48 ;add 48 to make ASCII char jmp short C4 ;jump ahead C3: add ah,55 ;A - F, so add 55 to make ASCII char C4: cmp al,9 ;repeat process for low nibble ja C5 ; (not looped here and elsewhere add al,48 ; for the sake of speed) jmp short C6 ; C5: add al,55 ; C6: mov es:[di],ah ;write the high nibble inc di ;move video buffer pointer to next col inc di ; stosb ;write the low nibble inc di ;move pointer to next col ;---WRITE THE HIGH AND LOW CHARS IN REVERSE IMAGE: C7: mov ah,112 ;code for reverse image mov al,bh ;get copy of high char stosw ;write it mov al,bl ;get copy of low char stosw ;write it ;---WRITE THE LOW BYTE IN HEX: mov bh,4 ;100B tests ctrl key test ds:[17h],bh ;chk BIOS variable whether ctrl key is down mov ah,bl ;copy of low byte to AH now, before jump taken jnz C9 ;if ctrl down, write the char in hex cmp ah,es:[di-162] ;test is char is the same as prior one jne C9 ;if not, write it in hex cmp ah,32 ;spc char is special case, since clears screen jne C8 ;if not spc, don't write hex equivalent cmp es:[di-160],ah ;if a spc, chk if it is one from CLRSCR je C9 ;if so, write out the hex code C8: add di,8 ;don't write hex, adjust buffer pointer jmp short C14 ;finished, go quit routine C9: shr ax,1 ;write out the two hex digits as above shr ax,1 ; shr ax,1 ; shr ax,1 ; shr al,1 ; shr al,1 ; shr al,1 ; shr al,1 ; cmp ah,9 ; ja C10 ; add ah,48 ; jmp short C11 ; C10: add ah,55 ; C11: cmp al,9 ; ja C12 ; add al,48 ; jmp short C13 ; C12: add al,55 ; C13: mov es:[di],ah ; inc di ; inc di ; stosb ; add di,5 ;forward buffer pointer to next register pos C14: pop ds ;restore changed registers pop bx ; ret ;quit hexwrite endp ;---THE REGISTER DISPLAY PROCEDURE STARTS HERE: regs: sti ;enable hardware interrupts pushf ;save flags cld ;set direction flag push ax ;these three re-restored at end push di ; since used in writing their own contents push es ; push es ;temporarily save ES and AX push ax ; while checking Alt key mov ax,40h ;point ES to BIOS data area mov es,ax ; mov ah,8 ;see if Alt key is down test es:[17h],ah ; pop ax ;restore ES and AX pop es ; jz D1 ;go ahead if Alt key not down jmp D5 ;else, quit the routine D1: push es ;push altered registers onto stack push ds ; in the left-right order in which they push di ; are displayed push si ; push cx ; push bx ; push ax ; mov ax,buffer ;now point ES to the video buffer mov es,ax ; push cs ;set DS to CS to get at bottom-of-screen labels pop ds ; ;---WRITE LABELS ON BOTTOM OF SCREEN: mov di,3842 ;ES:DI points to buffer position lea si,bottom ;DS:SI points to data string mov cx,10 ;there are 10 labels mov ah,112 ;will draw in reverse image D2: lodsb ;get a byte stosw ;write it with attribute lodsb ;etc... stosw ; lodsb ; stosw ; lodsb ; stosw ; lodsb ; stosw ; lodsb ; stosw ; add di,4 ;forward pointer to next label loop D2 ;go write next label ;---SCROLL THE 8TH - 24TH ROWS UPWARDS 1 LINE: push es ;set DS to video buffer address pop ds ; mov di,960 ;di points to start of 7th row mov si,1120 ;si points to start of 8th row mov cx,1360 ;number of chars+attribute to transfer rep movsw ;make the transfer ;---CLEAR 24TH ROW: mov cx,80 ;chars to clear mov ax,07FFH ;use FF as the 'space' char, 7 as the attribute mov di,3680 ;DI points to start of the line rep stosw ;clear it ;---DISPLAY THE REGISTERS: mov di,3682 ;point DI to position of first register pop ax ;momentarily restore AX contents call hexwrite ;write AX pop bx ;restore BX contents mov ax,bx ;move copy to AX call hexwrite ;write BX pop cx ;restore CX contents mov ax,cx ;move copy to AX call hexwrite ;write CX mov ax,dx ;DX unchanged, copy to AX call hexwrite ;write DX pop si ;restore SI contents mov ax,si ;move copy to AX call hexwrite ;write SI pop ax ;DI in use, pop contents straight into AX call hexwrite ;write DI mov ax,bp ;BP unchanged, copy to AX call hexwrite ;write BP mov ax,sp ;SP unchanged call hexwrite ;write SP pop ds ;restore DS mov ax,ds ;move copy to AX call hexwrite ;write DS pop ax ;ES in use, pop contents straight into AX call hexwrite ;write ES ;---CHECK SHIFT KEYS: mov ax,40h ;point ES back to BIOS data area mov es,ax ; D3: mov ah,8 ;1000B tests Alt key test es:[17h],ah ;is Alt down? jnz D5 ;if so, quit the routine mov ax,0102h ;1B in AH, 10B in AL test es:[17h],ah ;test right shift jnz D5 ;no delay if right shift down test es:[17h],al ;test left shift jz D3 ;keep looping until shift or Alt key down mov al,es:[6Ch] ;left shift down, read BIOS time-of-day add al,4 ;wait 4/18ths sec (may change this value) D4: cmp es:[6Ch],al ;read new time-of-day -- ready? jne D4 ;keep looping until ready D5: pop es ;done! restore registers used pop di ; to display the register values pop ax ; popf ; iret ;quit ;---------------------DRAW STACK PLUS REGISTERS--------------------------- all: int int_num ;call stack routine int int_num+2 ;call register routine iret ;done ;--------------------------SETUP CODE------------------------------------- finish equ $ ;mark end of code for int 27h below set_up: mov dx,offset stack ;point DX to start of STACK DISPLAY code mov al,int_num ;assign it to the base vector mov ah,25h ;DOS function to set interrupt vector int 21h ;set the vector mov dx,offset var ;point DX to start of DISPLAY VAR code mov al,int_num+1 ;assign it to the base vector + 1 int 21h ;set the vector mov dx,offset regs ;point DX to start of REGISTER DISPLAY code mov al,int_num+2 ;assign it to the base vector + 2 int 21h ;set the vector mov dx,offset all ;point DX to start of STACK PLUS REGS code mov al,int_num+3 ;assign it to the base vector + 3 int 21h ;set the vector mov ah,9 ;DOS function to write string lea dx,msg ;DS:DX pts to load message int 21h ;write the message lea dx,finish ;point DX to end of all resident code int 27h ;exit, leaving all resident except setup code cseg ends end begin