PSG register 7 and Joystick in OpenMSX | MSX Resource Center (Page 3/5)

Prophet (3505)

08-03-2019, 22:57

Manuel wrote:

Reason I ask: I implemented the feature, but now I need to know which machines are affected by bit 7

All machines with a discrete PSG should be affected.

The PSG type tag of the XML file could be used to differentiate this behaviour. But many XML files will have to be fixed, since they only seem to list "AY8910" or "YM2149", and never "S3527", "S1985", "T9769" etc.

Par Manuel

Ascended (18794)

08-03-2019, 23:09

Well, I implemented it as follows: if the MSX has the PSG in an engine IC, the port directions are ignored/fixed. But in case the MSX has a discrete PSG IC, it is not ignored and wrongly programming these bits will cause joystick trouble.

Par Grauw

Ascended (10581)

08-03-2019, 23:41

I think when the MSX has an Engine chip, the openMSX machine config files should perhaps list that rather than PSG, etc. separately. Then, particular behaviour quirks (such as this, mirroring, etc.) can be fixed in one go for whole classes of machines.

Par Manuel

Ascended (18794)

08-03-2019, 23:56

I've had that discussion with Wouter a couple of times, but he was not in favor of it. He wants to have the basics and build the machine based on that. But perhaps he can explain better himself

Par gdx

Enlighted (5508)

09-03-2019, 00:47

sd_snatcher wrote:

The PSG type tag of the XML file could be used to differentiate this behaviour. But many XML files will have to be fixed, since they only seem to list "AY8910" or "YM2149", and never "S3527", "S1985", "T9769" etc.

Not sure that other clones behave exactly the same way.

https://www.msx.org/wiki/PSG

Par Wlcracks

Champion (470)

09-03-2019, 08:05

YM2149F.
My VG8000 has an AY-3-8910, do i need to test that too?

Par Manuel

Ascended (18794)

09-03-2019, 10:16

Would be good to confirm that the problem also occurs on that 8000, although I am already quite sure it will.

Par Wlcracks

Champion (470)

09-03-2019, 11:45

real VG8000
- racing.rom v1.00 --- joystick trigger 1 only works in the "category: stock car" screen. No other joystick actions work.
- JOYTEST v2.4 FRS 12/2016 --- only direction in upper screen works and sometimes [B}, this thing is acting up wierd! Sometimes screen colors change and upper screen shows Akanoid paddle, devid 77h, MSX touchpad devid BBh.
- Basic Stick and trig - works fine
- JOYMEGA.COM Sergio Guerrero 1-2.00 -- works but shows trigger [B] [C]
- STICKTST.COM By Allosoft (lol) 08-12-1996 -- works as expected

Par Manuel

Ascended (18794)

09-03-2019, 12:41

lol at STICKTST.COM indeed! I had completely forgotten about it...

If you like, you can now try the same ROM in the latest openMSX development build, using the same machines... should behave the same now.

Par Wlcracks

Champion (470)

09-03-2019, 15:10

Will check asap. Curious to see if it the same. Thanks!