A86: recalling x and y variables into asm program to draw lines
[Prev][Next][Index][Thread]
A86: recalling x and y variables into asm program to draw lines
l have written an asm program which is supposed to draw a mouse cursor (like
for a GUl) and l'm having some trouble with it. for one thing even if x and
y are nonzero digits the program will still only draw a pixel in the middle
of the graph screen (if l'm lucky). sometimes (especially when being run
from another program) it will give a divide by zero error.
here's the code:
0004 D748 .org _asm_exec_ram
0005 D748
0006 D748 ProgStart:
0007 D748
0008 D748 CD E3 4C call _RCLX
0009 D74B CD 77 55 call _CONVOP1
0010 D74E 43 ld b, e
0011 D74F 53 ld d,e
0012 D750
0013 D750 CD DF 4C call _RCLY
0014 D753 CD 77 55 call _CONVOP1
0015 D756 4B ld c, e
0016 D757
0017 D757 1D dec e
0018 D758 1D dec e
0019 D759
0020 D759 CD E9 51 call _CLine
0021 D75C 26 02 ld h, 2
0022 D75E
0023 D75E 1D dec e
0024 D75F 14 inc d
0025 D760 14 inc d
0026 D761 14 inc d
0027 D762
0028 D762 CD E9 51 call _CLine
0029 D765 26 02 ld h, 2
0030 D767
0031 D767 15 dec d
0032 D768 1C inc e
0033 D769 1C inc e
0034 D76A 1C inc e
0035 D76B
0036 D76B CD E9 51 call _CLine
0037 D76E 26 02 ld h, 2
0038 D770
0039 D770 C9 ret
0040 D771
0041 D771
;-----------------------------------------------------
0042 D771 ; End of program
0043 D771
;-----------------------------------------------------
0044 D771 .end
tasm: Number of errors = 0