[Coco] VCC possible bug in 6309 & 6809 emulation and general Wally news!

Richard Cavell richardcavell at mail.com
Mon Jun 11 16:38:02 EDT 2018

What we really need is for someone to code a program that systematically tests this type of transfer, and run it on both real hardware and the emulators. Then bug report to any emulator that doesn’t produce the result that the real hardware arrives at.

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On 11/06/2018 at 14:41, Robert Gault wrote:

> Walter,
> Your observations of non-standard operations from the pdf are very interesting. The exchanges 
> between 8-bit and 16-bit registers and a Zero register are definitely not in the Hitachi Data book. 
> This information is also not mentioned in one of the better books on programming: "6809 Assembly 
> Language Programming" by Lance A. Leventhal, McGraw-Hill.
> Nevertheless, I did run a test on my Coco3 which has a 6309 chip and non-equal register transfers 
> work and there does seem to be a Zero register.
> A note to anyone using Tandy's EDTASM or my EDTASM6309, you can only perform these operations by 
> manually programming them with FCB statements. The assemblers will reject code such as:
> TFR X,A or TFR Z,A . You can, however, enter ex.   FCB $1F,$C8    which makes the 6309 clear regA. 
> $1F=TFR and %1100xxxx or %1101xxxx = from Z and %xxxx1000 = to regA.
> Robert
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