Search found 262 matches

by TascoDLX
Mon Feb 28, 2022 7:50 am
Forum: Mega/SegaCD
Topic: Popful Mail
Replies: 16
Views: 230403

Re: Popful Mail

Thanks for the intel, Eke! I will eventually circle back around to this issue, once I'm done clearing up some other stuff. I have only limited time to spend on emudev stuff and this particular issue went a bit deep, but it's definitely on the list. :wink:
by TascoDLX
Tue Mar 23, 2021 5:31 am
Forum: Super 32X
Topic: Questions on emulating the 32X
Replies: 14
Views: 160496

Re: Questions on emulating the 32X

1. I fail the Mars Test HINT (2) tests. The manual says an HCOUNT of 0 means every line, but from the Mars Test, I assume an HCOUNT of 1 is equal to 0 as every single line? Mars Test sets a value of 5, and reports "actual: 0000" if I take it to mean 6, or "actual: 061e" if I take it to mean 5. The ...
by TascoDLX
Mon Mar 08, 2021 7:51 am
Forum: Mega/SegaCD
Topic: Popful Mail
Replies: 16
Views: 230403

Re: Popful Mail

OK, here's the bug in Ares... In md/mcd/io.cpp, from line 208: if(address == 0xff8004) { if(lower) { cdc.address = data.bit(0,3); } if(upper) { cdc.transfer.destination = data.bit(0,2); // *** should be data.bit(8,10) } } There's probably a few other games that do word write to that register. Rex se...
by TascoDLX
Sun Mar 07, 2021 3:31 am
Forum: Mega/SegaCD
Topic: Popful Mail
Replies: 16
Views: 230403

Re: Popful Mail

Fuuuuuu... the bugs in that Radical Rex code, and that just in the initial loading routine. Really surprised it runs in any emulator at all. Seems like a frickin' miracle!
by TascoDLX
Sat Mar 06, 2021 3:23 am
Forum: Mega/SegaCD
Topic: Popful Mail
Replies: 16
Views: 230403

Re: Popful Mail

Excellent! It's truly my pleasure. It's great to see all the things your doing with Ares. :D
by TascoDLX
Fri Mar 05, 2021 5:29 am
Forum: Mega/SegaCD
Topic: Popful Mail
Replies: 16
Views: 230403

Re: Popful Mail

This has become my white whale ^-^; Call me Ishmael. :wink: Writing zero to the wordram control reg (from either side) does not affect 2M wordram assignment. Popful has both sides write to the wordram control reg (first MAIN, then SUB) then MAIN will read back the reg to verify. If it's the wrong v...
by TascoDLX
Sat Aug 24, 2019 9:09 am
Forum: Mega/SegaCD
Topic: Popful Mail
Replies: 16
Views: 230403

Re: Popful Mail

Traps are being used as normal function calls on the main CPU side to signal the sub CPU. Parameters are passed via the comm regs to tell the sub to execute certain functions, then main waits to sync up with sub on completion. Would need to look at trace past the first trap call to know what's going...
by TascoDLX
Mon Jun 17, 2019 5:12 pm
Forum: Mega/SegaCD
Topic: Documenting using the CD drive without the BIOS
Replies: 5
Views: 25105

Re: Documenting using the CD drive without the BIOS

The BIOS constantly polls the CDD for status (within the level 4 interrupt handler). As soon as it sees the track number change, it will initiate a pause. It uses a similar process when reading data sectors. Obviously the BIOS is also constantly checking CDD for error code, open tray, or any other u...
by TascoDLX
Thu May 23, 2019 6:43 am
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 117
Views: 6770995

Re: Questions on writing a new Mega CD emulator

Logs below ... any ideas this time? This is likely the last piece before I can boot some stuff :/ It looks like you're not performing the seek for the read command. The CDD treats the READ command as a seek leading into reading data. Contrast this with the SEEK command, which is treated as a seek l...
by TascoDLX
Sun May 05, 2019 8:21 am
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 117
Views: 6770995

Re: Questions on writing a new Mega CD emulator

Firebell pointed me at a weird issue in Silpheed that I did not understand: http://redump.org/disc/39378/ I didn't totally follow what they wrote about this either. I'll track down the image and take a look. Here's how I read it: Basically, there's a break in the data track. 7508 bytes of zero (pre...
by TascoDLX
Sat May 04, 2019 6:05 pm
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 117
Views: 6770995

Re: Questions on writing a new Mega CD emulator

Should we split data sectors' 304 bytes of extra data to take 2352-byte sectors to 2048-byte sectors, and then have a separate .ecc file? ECC is normally redundant data. Note that the 304 bytes also includes header/sync and CRC data. In most cases, all that data can be faithfully recreated. For ins...
by TascoDLX
Sat May 04, 2019 6:32 am
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 117
Views: 6770995

Re: Questions on writing a new Mega CD emulator

byuu wrote:
Sat May 04, 2019 5:49 am
If nothing can read it, is the TOC binary format encoded in the lead-in Q-channel even known at this point? ._.
http://www.13thmonkey.org/documentation ... c3r10g.pdf
see pdf page 63
by TascoDLX
Fri May 03, 2019 8:23 pm
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 117
Views: 6770995

Re: Questions on writing a new Mega CD emulator

Timecode is relative to start of the mandatory data track pre-gap, which also factors into the total time, I believe. So, track 1 start will be 00:02:00, and all subsequent tracks are offset accordingly (+2 seconds). You are correct that TOC is stored in q-channel within the lead-in. Pretty sure the...
by TascoDLX
Sun Apr 28, 2019 8:07 am
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 117
Views: 6770995

Re: Questions on writing a new Mega CD emulator

So it turns out the Z80 is driving the YM2612, which is where my audio is missing. It hits this routine and dies: https://github.com/DarkMorford/scd-bios ... g0.z#L1126 It seems to be a bug in the Z80 code that (remarkably) doesn't prevent the program from working properly, but you need to support ...
by TascoDLX
Thu Aug 09, 2018 5:43 am
Forum: Exodus
Topic: Incorrect disassembly of LINK instruction
Replies: 8
Views: 24448

Re: Incorrect disassembly of LINK instruction

Yeah, you don't want to be messing with formatting there. Probably going to break things. :D Actually, the existing code already has a mechanism for treating immediate data as signed, but it's a little hacky itself. Basically, all immediate data is automatically signed-extended and always disassembl...