Hi, I was wondering if anyone could help me with debugging this program? It's not printing out the way I expected it to, and I could use another set of eyes to help me figure out what's wrong with it. It's supposed to print out 3 vertical lines of X's of a length determined by the user, but isn't printing out the lines correctly. Thanks! Code: bdos equ 5 ; CP/M function call address boot equ 0 ; address to get back to CP/M conin equ 1 ; keyboard read function number conout equ 2 ; console output function number sprint equ 9 ; string print function number cr equ 0Dh ; value of ASCII code of <CR> lf equ 0Ah ; value of ASCII code of line feed ; org 0100h lxi sp,sp0 ;init stack mvi c, sprint lxi d, title ;calls first part of title at title call bdos mvi c, sprint lxi d, title2 ;calls second part of title call bdos call lines call print mvi c, sprint lxi d,endgraph call bdos lxi d,endmess call bdos jmp boot ;lines subroutine lines: mvi c, sprint lxi d, line1 ;prompts for 1st length call bdos ;1=b mvi c, conin call bdos mov b,a ;moves 1st length into b mvi c, sprint lxi d, line2 ;prompts for 2nd length call bdos mvi c, conin ;2=d call bdos mov d,a ;moves 2nd length into d push d mvi c, sprint lxi d, line3 ;prompts for 3rd length call bdos mvi c, conin ;3=h call bdos mov h,a ;moves 3rd length into h pop d ret ;print subroutine print: mvi c,conout push d ;keeps d from being overwritten lxi d,enter ;puts in an enter call bdos pop d mov a,b ;1st len to a cmp d ;1st-2nd jm sec ;2nd>=1st jz sec cmp h ;1st-3rd jm threeh ;3rd>=1st>2nd, otherwise is 1st>2nd>3rd jz threeh jmp oneh sec: mov a,d cmp h ;2nd-3rd jm threeh ;3rd>=2nd>=1st, otherwise 2nd is highest jz threeh jmp twoh oneh: mov a,b reponeh: cpi 0 rz ;ends prog once gets to end of 1s push d ;keeps d from being overwritten lxi d,xchar ;puts in an x call bdos mvi c,conout lxi d,fourspace ;puts in 4 spaces call bdos pop d call bdos cmp d ;1st-2nd jp twospace ;puts in space push d ;keeps d from being overwritten lxi d,xchar ;puts in an x call bdos two: lxi d,fourspace ;puts in 4 spaces call bdos call bdos cmp h ;1st-3rd jp threespace ;puts in space lxi d,xchar ;puts in an x call bdos three: sui 1 ;decriments counter lxi d,enter ;puts in an enter call bdos pop d jmp reponeh twospace: push d ;keeps d from being overwritten lxi d,space ;puts in a space call bdos jmp two threespace: lxi d,space ;puts in a space call bdos jmp three twoh: mov a,d reptwoh: cpi 0 rz cmp b ;2nd-1st jp twohonespace ;puts in space lxi d,xchar ;puts in an x call bdos twohone: lxi d,fourspace ;puts in 4 spaces call bdos lxi d,xchar ;puts in an x call bdos lxi d,fourspace ;puts in 4 spaces call bdos call bdos cmp h ;2nd-3rd jp twohthreespace ;puts in space lxi d,xchar ;puts in an x call bdos twohthree: sui 1 ;decriments counter lxi d,enter ;puts in an enter call bdos jmp reptwoh twohonespace: lxi d,space ;puts in a space call bdos jmp twohone twohthreespace: lxi d,space ;puts in a space call bdos jmp twohthree threeh: mov a, h repthreeh: cpi 0 rz cmp b ;3rd-1st jp threehonespace ;puts in space push d ;keeps d from being overwritten lxi d,xchar ;puts in an x call bdos threehone: lxi d,fourspace ;puts in 4 spaces call bdos pop d call bdos cmp d ;3rd-2nd jp threehtwospace push d ;keeps d from being overwritten lxi d,xchar ;puts in an x call bdos threehtwo: lxi d,fourspace ;puts in 4 spaces call bdos lxi d,xchar ;puts in an x call bdos sui 1 ;decriments counter lxi d,enter ;puts in an enter call bdos pop d jmp repthreeh threehonespace: lxi d,space ;puts in a space call bdos jmp threehone threehtwospace: push d ;keeps d from being overwritten lxi d,space ;puts in a space call bdos jmp threehtwo title: db 'Three Lines$' title2: db lf,cr, 'I will print three lines of given lengths$' line1: db lf,cr,'Length of first line: $' line2: db lf,cr,'Length of second line: $' line3: db lf,cr,'Length of third line: $' xchar: db 'X $' enter: db lf,cr, '$' fourspace: db ' $' space: db ' $' endgraph: db lf,cr, '1 2 3$' endmess: db lf,cr,'Thank you for using the Three Lines program$' ds 20 ;reserve for stack sp0 equ $ ;stack pointer address end
Can you give a couple of examples of the input you give and the output you got? It's easier to see where a program is going wrong with some output.
Right now if I put in something like Code: Length of first line: 6 Length of second line: 4 Length of third line: 2 I just get Code: 1 2 3 Thank you for using the Three Lines Program as output. But it should be giving me something more like Code: X X X X X X X X X X X X 1 2 3 Thank you for using the Three Lines Program I can't quite figure out where the program stops working, as the registers have the proper numbers in them.
