Project: HDMI/DVI out for STFM

[Smonson]

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.

[Icky]

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.

[exxos]

Icky, where did you get up to ?

Are you at a point to send me a not working setup ?

[Icky]

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 Model	Revision	Resetting	Shimmering without cap	Shimmering with 22pF	Comments
520 STM	C070243 REV. E	Yes	No	No	Rock 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 STFM	C070789-001 REV. C	No	Yes	No	Shimmering even present playing a game. Adding 22pF cap stops the shimmering
STF Remake	C070789-001 REV. F	Yes	No	No	Revision 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

Will give this a go and see what we get.

[Icky]

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.

[Smonson]

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 😊

[Icky]

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.

[Smonson]

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.

[Icky]

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.

Absolutely. The HDMI screen is a great feat and is going to be a great add-on board for us. Great work Smonson. :bravo:

There are some little boxes out there already that do DVI & Audio to HDMI but they aren't cheap or cheap cable to desktop speakers :D

[exxos]

:bravo:

So what exactly were the changes done to the new board ?