Visible graphics problems on SGDK-based game

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mikejmoffitt
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Re: Visible graphics problems on SGDK-based game

Post by mikejmoffitt » Thu Mar 03, 2016 7:28 pm

I am going to get my hands on my old Genesis 3 soon, which may produce different results. I haven't noticed any sound issues, but I wasn't listening for those as carefully as I was looking for graphical problems.

mikejmoffitt
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Re: Visible graphics problems on SGDK-based game

Post by mikejmoffitt » Sun Mar 27, 2016 10:26 pm

I brought my Genesis 3, and sure enough UMDK has no problems on it.

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prophet36
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Re: Visible graphics problems on SGDK-based game

Post by prophet36 » Sun Mar 27, 2016 10:49 pm

mikejmoffitt wrote:I brought my Genesis 3, and sure enough UMDK has no problems on it.
Ah, interesting. Presumably that's an NTSC machine? If so, that breaks the theory that it's a timing issue. At this point it looks like the MD1 is generally not compatible. I don't think I've heard of an MD2 or MD3 or Nomad not working with a UMDK cart, but as far as I'm aware only two MD1s have been seen to work, the rest have not.

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MintyTheCat
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Re: Visible graphics problems on SGDK-based game

Post by MintyTheCat » Mon Mar 28, 2016 6:28 pm

prophet36 wrote:
mikejmoffitt wrote:I brought my Genesis 3, and sure enough UMDK has no problems on it.
Ah, interesting. Presumably that's an NTSC machine? If so, that breaks the theory that it's a timing issue. At this point it looks like the MD1 is generally not compatible. I don't think I've heard of an MD2 or MD3 or Nomad not working with a UMDK cart, but as far as I'm aware only two MD1s have been seen to work, the rest have not.
The Genesis 3 was NTSC only and only available in the US that I know to.

We need to get the list of hardware and then carry out the same tests to work out what is going and then narrow down the issues.

The Genesis 3 is closer to the MD2 hardware wise.
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mikejmoffitt
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Re: Visible graphics problems on SGDK-based game

Post by mikejmoffitt » Fri Apr 01, 2016 3:45 pm

Yes, all NTSC. I'd believe it's a timing issue, and the later Genesis 2/3 has different timings than the first Genesis.

My Genesis 1 also has problems showing Stef's Bad Apple demo. The audio will develop serious issues about thirty seconds in, give or take. It's not perfectly consistent.

I would bet that the MD1s which worked were VA7 revisions, which were electrically more or less MD2s.

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MintyTheCat
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Re: Visible graphics problems on SGDK-based game

Post by MintyTheCat » Fri Apr 01, 2016 4:56 pm

Montserrat wrote:Also...did you notice some sound problems? like some random note out of nowhere? i get this from time to time.
As stated and I shall repeat: once we get a collection of MD hardware and we have a good representation of versions, revisions and regions (PAL & NTSC) and we have a set of tests to carry out on the hardware we will then be able to ascertain what works and then try to work out what the problems are.

We have only had a handful of people use UMDK and apart from me and Chris the others were made in the batch put together by Montserrat and we know that the hand soldered PCBs had issues. As such, not a lot can be relied up on: was it the UMDK code? Was it the manufacturer? Was it a particular version or revision of the board or the region that is the issue? We do not know enough as yet and until we organise ourselves and work out a test pool we will pretty much never know.

I have spoken to Chris about this idea of getting a test pool together and I have also made enquiries about getting UMDK manufactured professionally using automated tools - both of these factors would give us more reliable PCBs and stable hardware.
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