Project: HDMI/DVI out for STFM

[Smonson]

Sorry, forgot about that...

http://smonson.com/unmanaged/atari/shifter-test.hfe
http://smonson.com/unmanaged/atari/shifter-test.st

[exxos]

Program doesn't seem to be doing anything ?

IMG_3627.JPG

[exxos]

Tried in medium res..

now just stuck on this...

IMG_3628.JPG

[Smonson]

Doing nothing is good, it means it's only reading zeroes (or 1 in medium). Like me, your machine works with the mod for some unknown reason.

[exxos]

I removed the cap I added and this is what happens to the video...

( still get nothing in that program with the cap removed)

IMG_3630.JPG

Video is fine with the cap.

[exxos]

My observations:

• The latching behaviour is only level-sensitive, so high-frequency noise around the transitions shouldn't cause glitches
• The values that are being read seem very non-random, in the sense that either reads the whole word perfectly, or else it reads it with 8-12 wrong bits. It never reads just one wrong bit here and there. The pattern of bits is also very uniform, e.g. 0xb479 comes up a lot (see video and screenshot posted by Icky above)
• The reason I don't think it's clock related is that both Icky and Troed have the same behaviour, and Troed is using a totally different clock.

Could you get your program to output in binary instead ? Then be easier for people to see if any particular bit(s) are having issues...

[Smonson]

That's more good evidence that the register read problem isn't related to clock stability :dualthumbup:

The line of Xs is the value in binary.

[Smonson]

^ This is what it looks like on Icky's machine while running the test program.

Each line represents a read off the resolution register (the whole 16bit word) that differs from the previous value.

[exxos]

^ This is what it looks like on Icky's machine while running the test program.

Each line represents a read off the resolution register (the whole 16bit word) that differs from the previous value.

So what motherboard revisions are people using then ?

This is mine..

IMG_3631.JPG

Different boards tend to have different "faults".

Is everyone's HDMI board exactly like the one I have ?

[Smonson]

Mine's a C103414-001 rev 1.1.

The HDMI boards are all the same, unless I'm misremembering (V4).