Project: HDMI/DVI out for STFM

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rubber_jonnie
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Re: Project: HDMI/DVI out for STFM

Post by rubber_jonnie » Mon Mar 25, 2019 10:49 am

FYI I did a test on a different, not blittered machine last night, and all seemed fine at low and med res.

At hi res, I got this:
IMG_20190324_233819.jpg
IMG_20190324_233819.jpg (600.01 KiB) Viewed 781 times
There is an obvious shift/step on the LH end of the screen

However, it behaved impeccably otherwise, with all resolutions stable and clear, and no blanking.

I'll try to go through my stack of STFMs and work out which have a blitter (They are actually closed up!) as I'll need to know before pulling them apart. I also have no idea which machines have a socketed shifter, so some checking is needed.
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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Smonson
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Re: Project: HDMI/DVI out for STFM

Post by Smonson » Mon Mar 25, 2019 11:45 am

That effect comes from the ST and shifter being out of sync with each other. The shifter only gets reset at boot time, when the internal registers are cleared, and after that if it receives an extra LOAD it gets out of sync like this and stays that way until the next reset when it should go back to normal. I don't know why this happens to the FPGA shifter and apparently not the physical shifter :/

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Re: Project: HDMI/DVI out for STFM

Post by exxos » Mon Mar 25, 2019 11:50 am

Maybe its just a fluke.. that the actual shifter is to slow or not finished setting up internally to "see" the load pulse ? No idea :( Could you "skip" the extra load on power up ? Though I imagine as not all machines suffer, that would create more issues ?

BTW - did you ever look at the suska video core, see if any ideas in there ?
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

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Smonson
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Re: Project: HDMI/DVI out for STFM

Post by Smonson » Mon Mar 25, 2019 12:11 pm

The problem with skipping is knowing which ones to skip. It could also be caused by some other mechanism of course, an unknown unknown.

I've never looked at the suska source actually. Maybe I should learn VHDL.

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Re: Project: HDMI/DVI out for STFM

Post by rubber_jonnie » Mon Mar 25, 2019 12:12 pm

Give me a bit more time to suss out my other blittered non blittered machines and I'll get more testing done.
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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Re: Project: HDMI/DVI out for STFM

Post by exxos » Mon Mar 25, 2019 12:35 pm

I think myself and troed saw this issue when we did the 16MHz boost.. Maybe troed remembers more.. but I think it was actually a sync issue between the MMU & GLUE 8MHz clock.. Where some small delay caused random sync issues..

Doesn't look like I documented it, but RJ could possibly try a small pF like 47pF on the 8MHz line on the bottom of the GLUE and see if that helps (or makes it worse even) .. its possible it may need a series resistor... Its also possible it could be a sync issue with DE from GLUE to MMU as well..

So I think this is just another buggy ST fault where the original atari logic is to slow and dumb for the problem to cause issues...
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

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Re: Project: HDMI/DVI out for STFM

Post by rubber_jonnie » Mon Mar 25, 2019 12:38 pm

exxos wrote:
Mon Mar 25, 2019 12:35 pm
Doesn't look like I documented it, but RJ could possibly try a small pF like 47pF on the 8MHz line on the bottom of the GLUE and see if that helps (or makes it worse even) .. its possible it may need a series resistor... Its also possible it could be a sync issue with DE from GLUE to MMU as well..
I'll see what I can do, can you please advise on the pin I need to connect to on the GLUE?
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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Re: Project: HDMI/DVI out for STFM

Post by exxos » Mon Mar 25, 2019 12:47 pm

rubber_jonnie wrote:
Mon Mar 25, 2019 12:38 pm
I'll see what I can do, can you please advise on the pin I need to connect to on the GLUE?
GLUE pin 34. It comes from 8MHz clock pin on the 68000 ( pin 15) .
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxoshost.co.uk/atari/last/storenew/ - All my hardware mods for sale - Please help support by making a purchase.

troed
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Re: Project: HDMI/DVI out for STFM

Post by troed » Mon Mar 25, 2019 12:48 pm

Well, yes, when doing the doubleST I do get this effect and use a small AUTO program to "clear" the Shifter (same as fullscreen demos do) which seems to work pretty well.

I'll need to look into my test code and see if it's in a state where I can attach the program here (and also if it works in mono, not sure).

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Re: Project: HDMI/DVI out for STFM

Post by rubber_jonnie » Mon Mar 25, 2019 2:17 pm

exxos wrote:
Mon Mar 25, 2019 12:47 pm
rubber_jonnie wrote:
Mon Mar 25, 2019 12:38 pm
I'll see what I can do, can you please advise on the pin I need to connect to on the GLUE?
GLUE pin 34. It comes from 8MHz clock pin on the 68000 ( pin 15) .
Sorry for the questions,as you know my electronics knowledge is still slowly building, but where is the other end of the cap supposed to go? GND? or elsewhere?
Collector of old Atari things:
800XL + Ape Warp mod, 2x 1010 cassette, 1050 + Happy mod, 65XE (128k) & XC12, SIO2SD, 2600jr, 7800 and Lynx II
Atari 520ST (1Meg) + Gotek, 1040STFM + Vortex ATOnce + Gotek, 1040STF long button floppy, 4160 STE with Gotek and ROM switcher, 4160STE with 32Mhz booster, ROM switcher and CosmosEx, not to mention various bare ST boards for testing including a PAK 68/2 :)
Plus the rest..
Amiga stuff, Mac stuff, Sinclair stuff etc...
www.electronicnothingness.co.uk

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