Page 1 of 2

Shifter Behaviour

Posted: 22 Sep 2025 10:46
by GadgetUK164
Another STM related question here - for you lovely super experienced ST people =D

PP adapted games when run from HDD - they usually show the "box art" using a display mode where extra colours are "tricked" into existance. You will know what I mean if you've played any of PP's HDD adapted games.

On my STFM the box art displays perfectly when in 8Mhz mode, when switched into 16Mhz the image gets messed up, due to the timing being knocked out completely with the 16Mhz... That makes sense!

On this STM - stock CPU, I see the same type of issue where the "box art" screen is messed up. What was different about the STM - were later modifications done by the time we got to the STFM which means PP's technique of trying to display box art wont work?!?!

Or is there a change a mod or fix might be required to the shifter section, or a different shifter needed? This STM originally had a 512KB upgrade fitted under the shifter, I simply removed that and the wires to DRAM, and MMU, then fitted shifter back into its socket. Did I miss something there in relation to a mod need to shifter area when an old 512MB upgrade was in there?

20250922_105711.jpg

Re: Shifter Behaviour

Posted: 22 Sep 2025 10:52
by exxos
Different shifter revision ? Try swapping them with your STFM ?

Re: Shifter Behaviour

Posted: 22 Sep 2025 10:55
by rubber_jonnie
I'm guessing the STM is like mine and has no Blitter, so could be related to that.

Re: Shifter Behaviour

Posted: 22 Sep 2025 10:59
by GadgetUK164
I've added a photo there - you can see its the later shifter?!? Lots of wires though - are those all factory?

Re: Shifter Behaviour

Posted: 22 Sep 2025 11:24
by GadgetUK164
rubber_jonnie wrote: 22 Sep 2025 10:55 I'm guessing the STM is like mine and has no Blitter, so could be related to that.
Yes - no MMU socket! Are you aware of why yours has this issue?

Re: Shifter Behaviour

Posted: 22 Sep 2025 12:28
by rubber_jonnie
GadgetUK164 wrote: 22 Sep 2025 11:24
rubber_jonnie wrote: 22 Sep 2025 10:55 I'm guessing the STM is like mine and has no Blitter, so could be related to that.
Yes - no MMU socket! Are you aware of why yours has this issue?
Did you mean no Blitter socket? If it didn't have an MMU it wouldn't be running :)

I don't know if mine has the same issue but if you have some specific games from PP let me know what they are, if I can get a chance I could try them.

Re: Shifter Behaviour

Posted: 22 Sep 2025 12:30
by prog99
Ignoring anything PP has done.
Does Closure work, it gives the chipset a decent workout. https://demozoo.org/productions/151601/

Re: Shifter Behaviour

Posted: 22 Sep 2025 12:56
by GadgetUK164
rubber_jonnie wrote: 22 Sep 2025 12:28
GadgetUK164 wrote: 22 Sep 2025 11:24

Yes - no MMU socket! Are you aware of why yours has this issue?
Did you mean no Blitter socket? If it didn't have an MMU it wouldn't be running :)

I don't know if mine has the same issue but if you have some specific games from PP let me know what they are, if I can get a chance I could try them.
Haha, yes - Blitter! Not MMU =P

Xenophobe for example - its just the "cover art" screen.

Re: Shifter Behaviour

Posted: 22 Sep 2025 12:56
by GadgetUK164
prog99 wrote: 22 Sep 2025 12:30 Ignoring anything PP has done.
Does Closure work, it gives the chipset a decent workout. https://demozoo.org/productions/151601/
Will give it a go thanks!

EDIT: I tried an IMP shifter btw - same issue...

Re: Shifter Behaviour

Posted: 22 Sep 2025 12:59
by Steve
Could all those wires be some form of composite mod I wonder...