PSG registers: incongruent values

By MicroTech

Champion (352)

MicroTech's picture

22-10-2008, 17:09

Hi MSX users,
I'm interested in driving bits 0..3 of PSG R#15.
To begin I wrote a simple C program that reads all psg registers (both directly and through bios) but I find differences between values read in OpenMSX and BlueMSX.
Both emulators are configured as turboR machines with no peripherals connected to joystick ports.
Here are the different register/values read from my program:

          OpenMSX            BlueMSX
R#7      0xB8                      0x38
R#14    0xFF                      0x7F
R#15    0xCF                     0xC0

Moreover BlueMSX debugger shows PSG "Peripheral registers" #15 = 0xCC... so still different from the value reported by software.
Am I missing something Question
Thanks

P.S.: hope to be able to try this evening on real turboR machine
P.P.S.: sorry for bad tabs

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By Manuel

Ascended (10064)

Manuel's picture

22-10-2008, 20:27

I get this on openMSX:
0xB8
0x7F
0xCF

And I get the same on my real turboR GT.

By MicroTech

Champion (352)

MicroTech's picture

23-10-2008, 09:41

Hi manuel,
I agree that openMSX is very accurate.
What sounds "strange" to me is that:
1) BlueMSX reports R#7 bit 7 = 0 (should (MUST) not happen on real machines)
2) BlueMSX reports R#15 bits 3..0 = 0 but they should be pulled-up
I forgot to say that BlueMSX, I currently use, is version 2.7.1.

BTW is there any plan to add "Acrobat 232" cable emulation?
Thanks

By Manuel

Ascended (10064)

Manuel's picture

23-10-2008, 13:22

For blueMSX, better ask dvik.

What is "Acrobat 232" cable?

By MsxKun

Paladin (704)

MsxKun's picture

23-10-2008, 13:50

Yes, that same thingy at BlueMSX report of R#7 happened to me a few before and confused me...

By MicroTech

Champion (352)

MicroTech's picture

23-10-2008, 15:08

What is "Acrobat 232" cable?

Goggling a bit with "MSX Acrobat 232" you should find something (very little indeed)

It is a TTL <-> RS232 level adapter designed to work with MSX joystick port.
The "package" also contains software to drive a modem and transfer files... but that's all in Japanese and, for me, a bit difficult to use.
Hence I'd like to drive joystick pins by myself.

P.S.: I don't know if Mr. Aozakana considers his product freeware

By Manuel

Ascended (10064)

Manuel's picture

23-10-2008, 22:36

If we don't know what it is (in big detail!) and we don't have software to test it, it will not be implemented. If you really want/need it, feel free to enter a Feature Request item in our trackers, so that we don't forget and you can track progress.

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