#994 6509 processor emulation bugs

[Michau]

Mound the attached D80 image in VICE. Type:

BLOAD "*"
SYS 1024

(note that this is BLOAD, not DLOAD).

The last three tests fall in VICE but they work on real machine.

Test "read_back_direct_2" and "read_back_indirect_2" show a simple bug in reading the value written to $00/$01 register - on the real 6509, only four bits are used, so when you write FF, you should read back 0F. Test "read_back_indirect_1" shows (I think) that on a real machine, even LDA (xx),Y reads the CPU register when accessing $00/$01 whereas in Vice it seems to read underlying memory.

Source code for the tests:
https://github.com/MichalPleban/6509-test

[Marco van den Heuvel]

Fixed in rev 34557, please retest.

Nice catch btw, this bug has gone unnoticed probably since xcbm2 was added to the project.

[Querino]

seems ok?

[compyx]

Works for me too, closing.