Search found 86 matches

by mikejmoffitt
Thu May 25, 2017 8:18 am
Forum: Mega/SegaCD
Topic: SEGA CD Mode 1
Replies: 46
Views: 32709

Re: SEGA CD Mode 1

You can use the HV counter to introduce a psuedorandom number into track selection.
by mikejmoffitt
Fri Apr 21, 2017 4:11 am
Forum: Collaboration
Topic: My mate is producing a musicdisk
Replies: 5
Views: 1681

Re: My mate is producing a musicdisk

I'd contribute one, I guess?
by mikejmoffitt
Mon Apr 17, 2017 6:08 am
Forum: Demos
Topic: OVERDRIVE II
Replies: 29
Views: 8268

Re: OVERDRIVE II

Model: MD1 VA2 JP Serial: 89N51082 No pic of VDP/ASIC, but it's nothing out of the ordinary. Glitches experienced: With VDP Debug register blending stuff enabled, sprites showed blank or glitchy columns every 8 pixels; looks like a driving conflict or open bus behavior. Matches what I've seen with p...
by mikejmoffitt
Sun Apr 16, 2017 6:27 pm
Forum: Demos
Topic: OVERDRIVE II
Replies: 29
Views: 8268

Re: OVERDRIVE II

This turned out great! Runs a little funny on my VA2 JP Model 1, as "that register" has some odd vertical lines every pixel on the very original chipset.
by mikejmoffitt
Fri Apr 14, 2017 6:31 pm
Forum: SGDK
Topic: SRAM with 4MiB game?
Replies: 1
Views: 660

SRAM with 4MiB game?

I am anticipating that my game will grow larger than 2MiB. From what I can gather, a typical arrangement for a <=2MiB game is that SRAM is mapped to the upper 2MiB of addresss space while the ROM is mapped to the lower 2MiB (starting at 0x000000). For a game that has grown considerably, does SGDK ha...
by mikejmoffitt
Thu Jul 21, 2016 5:48 pm
Forum: Hardware
Topic: Hmmmm.......?
Replies: 25
Views: 9215

Re: Hmmmm.......?

I missed this thread until now. I'm very interested in your cartridge as well. I have a great capture card and can test anything for you.
by mikejmoffitt
Thu May 19, 2016 9:34 pm
Forum: SGDK
Topic: Sound analyzer
Replies: 10
Views: 2051

Re: Sound analyzer

If you can read the digital output data, you're still going to have to implement a fast-fourier transform and generate visuals with that. You would be better off reading the registers of the YM2612, and reading the frequency and multipliers of all modulators to determine mathematically the response ...
by mikejmoffitt
Fri Apr 01, 2016 3:45 pm
Forum: UMDK
Topic: Visible graphics problems on SGDK-based game
Replies: 20
Views: 5210

Re: Visible graphics problems on SGDK-based game

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 be...
by mikejmoffitt
Sun Mar 27, 2016 10:26 pm
Forum: UMDK
Topic: Visible graphics problems on SGDK-based game
Replies: 20
Views: 5210

Re: Visible graphics problems on SGDK-based game

I brought my Genesis 3, and sure enough UMDK has no problems on it.
by mikejmoffitt
Thu Mar 03, 2016 7:28 pm
Forum: UMDK
Topic: Visible graphics problems on SGDK-based game
Replies: 20
Views: 5210

Re: Visible graphics problems on SGDK-based game

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.
by mikejmoffitt
Sun Feb 14, 2016 9:55 pm
Forum: UMDK
Topic: Visible graphics problems on SGDK-based game
Replies: 20
Views: 5210

Re: Visible graphics problems on SGDK-based game

mswan's UMDK kit works and produces the exact same problems that mine does with regards to minor corruptions in DMA transfers.
by mikejmoffitt
Sun Feb 14, 2016 9:37 pm
Forum: UMDK
Topic: UMDK manufacturing, part 2: Software
Replies: 253
Views: 37105

Re: UMDK manufacturing, part 2: Software

Sure enough, that did help. We're going through the last tests now.
by mikejmoffitt
Sat Feb 13, 2016 10:31 pm
Forum: UMDK
Topic: UMDK manufacturing, part 2: Software
Replies: 253
Views: 37105

Re: UMDK manufacturing, part 2: Software

I may not have been clear enough in my post, but I stated that if I use my PCB (as opposed to his) it works without any issues. I've tried it as root, which didn't help. I will see if hwinfo shows anytihng useful though.
by mikejmoffitt
Sat Feb 13, 2016 12:22 am
Forum: UMDK
Topic: Visible graphics problems on SGDK-based game
Replies: 20
Views: 5210

Re: Visible graphics problems on SGDK-based game

Okay, so I did some testing and found some commercial games with the exact same problem. Sonic 3 has Sonic's sprite tile data loaded into VRAM whenever his frame changes, and there are similar speckles of wrong data in place, indicating a DMA corruption. Interestingly the palette data is rewritten e...
by mikejmoffitt
Fri Feb 12, 2016 11:57 pm
Forum: UMDK
Topic: UMDK manufacturing, part 2: Software
Replies: 253
Views: 37105

Re: UMDK manufacturing, part 2: Software

I have been working with mswan to get his UMDK board working. Unfortunately, we're stuck here: http://i.imgur.com/Obi19ZH.png On my UMDK, this command is fine, so it's not a problem with udev rules or any such configuration. Voltages all check out as fine on the board, and the Cypress device does en...