10 Dec
2005
10 Dec
'05
7:37 p.m.
On Sat, 10 Dec 2005, J.C. Wren wrote:
My CP/M machine is in storage at the moment, but I
have the vague
recollection that the single DAA version doesn't work on the 8080, or
possibly the Z80. I know I first used this code on one of those two,
and I spent some time playing around with it. Does this sound familiar
to you?
Sorry, don't remember. These all work with 80x86
Fred Cisin wrote:
>>> AND AL,00fh
>>> ADD AL,090h
>>> DAA
>>> ADC AL,040h
>>> DAA
>>> RET
>>>
>>>
>or:
>
>AND AL, 0Fh
>DAA
>ADD AL, 0F0h
>ADC AL, 40h
>
>or:
>
>AND AL, 0Fh
>ADD AL, 0
>ADC AL,28h
>DAA
>
>
>and, of course, it can be extended to 16 bits with screen display by:
>
> MOV CX, 0404h ; CH and CL are independent
>N1: ROL AX, CL
> PUSH AX
> AND AL, 0Fh
>
> DAA
> ADD AL, 0F0h
> ADC AL, 40h
>
> MOV AH, 0Eh ;displays char in AL at cursor position
> INT 10h
>
> POP AX
> DEC CH
> JNZ N1
>
>
>--
>Grumpy Ol' Fred cisin at xenosoft.com