Project: HDMI/DVI out for STFM

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Icky
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Re: Project: HDMI/DVI out for STFM

Post by Icky » Sat Jan 05, 2019 8:06 pm

Icky wrote:
Sat Jan 05, 2019 6:46 pm
exxos wrote:
Fri Jan 04, 2019 9:38 pm


Very odd..

Add this cap and I bet you be working fine...


viewtopic.php?f=29&t=330&start=270#p14777
Out of interest what value did you use?
10nF actually made the board not work - black screen.

47pF works fine.

Screen is now stable on STFM.

EDIT: Just tried the HDMI board back in the STF Remake and 520ST with the 47pF cap in place and its even more temperamental. Some times its just a blank screen like when I used the 10nF when in the STFM and not very often it might try to boot and of course reset. On reset it mostly goes back to blank. I guess the 16MHz line is not so happy in these two machines with the cap on it.

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Re: Project: HDMI/DVI out for STFM

Post by exxos » Sat Jan 05, 2019 9:01 pm

Icky wrote:
Sat Jan 05, 2019 8:06 pm
10nF actually made the board not work - black screen.

47pF works fine.

Screen is now stable on STFM.

EDIT: Just tried the HDMI board back in the STF Remake and 520ST with the 47pF cap in place and its even more temperamental. Some times its just a blank screen like when I used the 10nF when in the STFM and not very often it might try to boot and of course reset. On reset it mostly goes back to blank. I guess the 16MHz line is not so happy in these two machines with the cap on it.
Anything over about 390pF will squash the signal to much. Its not a good fix, but I still suspect its a clocking issue.
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 » Sun Jan 06, 2019 7:56 am

I used 22pF on the new boards. It's been working fine for my machine. The best place to solder them in is underneath the 34-pin IDC cable pins - pin 1 being the clock, and any of the surrounding pins being ground.

Speaking of the new boards, I have 3 built now (the shifter socket adapter boards, that is) from the Schmitt trigger design, each tested for 30min. I'll be sending these out shortly to the three of you who have given me your postal address. These should hopefully give you a better clock signal.

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Re: Project: HDMI/DVI out for STFM

Post by Icky » Sun Jan 06, 2019 10:28 am

Smonson wrote:
Sun Jan 06, 2019 7:56 am
I used 22pF on the new boards. It's been working fine for my machine. The best place to solder them in is underneath the 34-pin IDC cable pins - pin 1 being the clock, and any of the surrounding pins being ground.

Speaking of the new boards, I have 3 built now (the shifter socket adapter boards, that is) from the Schmitt trigger design, each tested for 30min. I'll be sending these out shortly to the three of you who have given me your postal address. These should hopefully give you a better clock signal.
Thanks Smonson. I think I will try a lower value 22pF as you have used to see if it still works in the STFM and then see if its effect in the 520ST.

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Re: Project: HDMI/DVI out for STFM

Post by exxos » Mon Jan 21, 2019 10:31 am

Icky, where did you get up to ?

Are you at a point to send me a not working setup ?
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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Icky
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Re: Project: HDMI/DVI out for STFM

Post by Icky » Tue Jan 22, 2019 11:29 am

exxos wrote:
Mon Jan 21, 2019 10:31 am
Icky, where did you get up to ?

Are you at a point to send me a not working setup ?
Just to update my table of where we are:

ST ModelRevisionResettingShimmering without capShimmering with 22pFComments
520 STMC070243 REV. EYesNoNoRock solid display can be seen if you can get it past resetting and playing a game. Setting PSU to 4.3V and the ST boots and doesn't reset but there isn't enough power to supply floppy but I could get Gigafile to operate
520 STFMC070789-001 REV. CNoYesNoShimmering even present playing a game. Adding 22pF cap stops the shimmering
STF RemakeC070789-001 REV. FYesNoNoRevision is from the donor STFM that gave the remake most of its parts. Seems to exhibit same behaviour as 520ST including dropping the voltage.

Smonson has kindly sent through a new shifter board which arrived this morning.

IMG_3518.jpg
IMG_3518.jpg (112.83 KiB) Viewed 802 times

Will give this a go and see what we get.

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Re: Project: HDMI/DVI out for STFM

Post by Icky » Wed Jan 23, 2019 11:18 pm

Well hats off to you Smonson.

:cheer: :cheer: :cheer: :cheer: :cheer:

New board placed in STF Remake and no resets. Put back in the old board and it immediately started reseting.

Have been using this tonight for quite a few ST apps and the screen is stunning. It's clear, crisp and colourful.

All I need now is to find my HDMI recorder to get a crystal clear video instead on my constantly focusing phone camera.


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Re: Project: HDMI/DVI out for STFM

Post by Smonson » Wed Jan 23, 2019 11:44 pm

Great to hear! Thanks for the update Icky.

Perhaps there is some relationship between the clock and the resetting behaviour after all. Interesting.

Now you can bask in that pure radioactive green colour with no analogue degredation 😊

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Re: Project: HDMI/DVI out for STFM

Post by Icky » Wed Jan 23, 2019 11:51 pm

Smonson wrote:
Wed Jan 23, 2019 11:44 pm
Great to hear! Thanks for the update Icky.

Perhaps there is some relationship between the clock and the resetting behaviour after all. Interesting.

Now you can bask in that pure radioactive green colour with no analogue degredation 😊
Exxos and I were discussing the board and I had forgotten to test it. Did the test and the result is as you see. Exxos suggested I measured the two boards on the machines that exhibited the resetting so we know what the differences are. I will get to that soon.

Just finished a level of Volfied using the HDMI board brilliant colour and quality.

You know what's coming now. :) How do we get sound down that HDMI cable from the ST as well.

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Re: Project: HDMI/DVI out for STFM

Post by Smonson » Wed Jan 23, 2019 11:57 pm

I gather that I'd have to write some pretty advanced verilog to generate the audio packets. I haven't really looked into it all that much, better to get one thing working at a time.

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