[Coco] Errors in Leventhal's 6809 Subroutines book?
Johann Klasek
johann+coco at klasek.at
Tue Feb 1 14:30:40 EST 2022
On Sun, Jan 30, 2022 at 12:21:28PM +0900, Joel Rees wrote:
[..]
> Here's the nitty-gritty:
[..]
> -------- line 162 of MPBMUL.s --------
>
> 160:SETUP:
> 161: LDX ,S ; GET SHIFT COUNT
> 162: LEAX -1,S ; DECREMENT SHIFT COUNT BY 1
> 163: STX ,S
> 164: BNE SHFTST ; CONTINUE UNLESS SHIFT COUNT EXHAUSTED
>
> As a simple fix, add one line:
>
> 160:SETUP:
> 161: LDX ,S ; GET SHIFT COUNT
> 162: LEAX -1,X ; DECREMENT SHIFT COUNT BY 1
> 163: STX ,S
> 164: BNE SHFTST ; CONTINUE UNLESS SHIFT COUNT EXHAUSTED
>
> Note that both LEAX and STX set the Z flag, so that is not a problem here.
>
> -------- end line 162 of MPBMUL.s --------
Probably some kind of copy&paste error,
the above is part of 6809_MPBDIV.s, not of MPBMUL.s. ;)
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