Search found 262 matches
- Mon Feb 28, 2022 7:50 am
- Forum: Mega/SegaCD
- Topic: Popful Mail
- Replies: 17
- Views: 351055
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.
- Tue Mar 23, 2021 5:31 am
- Forum: Super 32X
- Topic: Questions on emulating the 32X
- Replies: 14
- Views: 244979
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 ...
- Mon Mar 08, 2021 7:51 am
- Forum: Mega/SegaCD
- Topic: Popful Mail
- Replies: 17
- Views: 351055
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...
- Sun Mar 07, 2021 3:31 am
- Forum: Mega/SegaCD
- Topic: Popful Mail
- Replies: 17
- Views: 351055
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!
- Sat Mar 06, 2021 3:23 am
- Forum: Mega/SegaCD
- Topic: Popful Mail
- Replies: 17
- Views: 351055
Re: Popful Mail
Excellent! It's truly my pleasure. It's great to see all the things your doing with Ares.
- Fri Mar 05, 2021 5:29 am
- Forum: Mega/SegaCD
- Topic: Popful Mail
- Replies: 17
- Views: 351055
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...
- Sat Aug 24, 2019 9:09 am
- Forum: Mega/SegaCD
- Topic: Popful Mail
- Replies: 17
- Views: 351055
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...
- Mon Jun 17, 2019 5:12 pm
- Forum: Mega/SegaCD
- Topic: Documenting using the CD drive without the BIOS
- Replies: 5
- Views: 36188
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...
- Thu May 23, 2019 6:43 am
- Forum: Mega/SegaCD
- Topic: Questions on writing a new Mega CD emulator
- Replies: 117
- Views: 10956218
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...
- Sun May 05, 2019 8:21 am
- Forum: Mega/SegaCD
- Topic: Questions on writing a new Mega CD emulator
- Replies: 117
- Views: 10956218
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...
- Sat May 04, 2019 6:05 pm
- Forum: Mega/SegaCD
- Topic: Questions on writing a new Mega CD emulator
- Replies: 117
- Views: 10956218
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...
- Sat May 04, 2019 6:32 am
- Forum: Mega/SegaCD
- Topic: Questions on writing a new Mega CD emulator
- Replies: 117
- Views: 10956218
- Fri May 03, 2019 8:23 pm
- Forum: Mega/SegaCD
- Topic: Questions on writing a new Mega CD emulator
- Replies: 117
- Views: 10956218
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...
- Sun Apr 28, 2019 8:07 am
- Forum: Mega/SegaCD
- Topic: Questions on writing a new Mega CD emulator
- Replies: 117
- Views: 10956218
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 ...
- Thu Aug 09, 2018 5:43 am
- Forum: Exodus
- Topic: Incorrect disassembly of LINK instruction
- Replies: 8
- Views: 34391
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...