Search found 15 matches
- Fri Jul 01, 2016 3:44 pm
- Forum: Exodus
- Topic: Mocking up a Sega CD
- Replies: 5
- Views: 12195
Re: Mocking up a Sega CD
I'm still interested in working on this for my own use and possibly contributing more formally to Exodus in the future to get Sega CD support working. I'm just not entirely sure where to start on it—do I start with the XML module file and then code the chips to fit that? Just start jumping in to the...
- Thu Nov 26, 2015 1:09 am
- Forum: Mega/SegaCD
- Topic: Sega CD (US) BIOS Disassembly @ GitHub
- Replies: 7
- Views: 14332
Re: Sega CD (US) BIOS Disassembly @ GitHub
Ah, I stand corrected. Haven't gotten to the CD player portion of the BIOS code yet.
- Wed Nov 25, 2015 6:35 pm
- Forum: Mega/SegaCD
- Topic: Sega CD (US) BIOS Disassembly @ GitHub
- Replies: 7
- Views: 14332
Re:
I'd like to approach this situation to ask for something I wanted to know since the start: How are the CDDA decibels read? I must have being missing something, but I really can't find anything about. I'm not entirely sure I understand your question, to be honest. Assuming you're talking about a gam...
- Fri Nov 13, 2015 11:57 pm
- Forum: Exodus
- Topic: Mocking up a Sega CD
- Replies: 5
- Views: 12195
Re: Mocking up a Sega CD
Thanks, Nemesis, that makes a lot of sense. I do have schematics for the Sega CD floating around somewhere, I just need to find a place that'll print them full-size (A3 paper) so I have that for reference. As I mentioned in my original post, I'd like to make a "dumb" (i.e., not 100% accurate) 315-55...
- Wed Jul 29, 2015 2:05 am
- Forum: Exodus
- Topic: Mocking up a Sega CD
- Replies: 5
- Views: 12195
Okay, so I've started adding a few more bits and pieces to my module configuration to be hooked in later; the full file is over on pastebin (to prevent a huge copy-paste in here). I can load this into Exodus, load the RAM image with the sub-CPU programs, and for the most part it's doing what I expec...
- Tue Jul 28, 2015 2:04 am
- Forum: Exodus
- Topic: Mocking up a Sega CD
- Replies: 5
- Views: 12195
Mocking up a Sega CD
I'm trying to "wire up" a system in Exodus to help with disassembling/analyzing the Sega CD BIOS. For now I'm just wanting to mock up the main parts; I'll worry about accuracy later. Just to get started, I'm trying to hook up the 4 Mbit PRG-RAM, the two 1 Mbit Word RAM banks, and a fake set of Gate ...
- Wed Jul 22, 2015 9:30 pm
- Forum: Mega/SegaCD
- Topic: CD Initial Program (IP) trying to write to ROM
- Replies: 3
- Views: 9581
I think the Z80's reset pin is active low, so writing a one is actually releasing reset not asserting it. Ah, that's right. I keep forgetting that the bus-request and reset lines are opposites, and I was thrown off because it didn't follow the "normal" sequence for talking to the Z80. I would guess...
- Wed Jul 22, 2015 8:51 pm
- Forum: Mega/SegaCD
- Topic: CD Initial Program (IP) trying to write to ROM
- Replies: 3
- Views: 9581
CD Initial Program (IP) trying to write to ROM
In working on my BIOS disassembly, I've started taking a look at some commercial software to see how they interact with it. I came across this curious bit of code in the IP of "Penn and Teller's Smoke & Mirrors," and I'm not quite sure what to make of it. loc_FF0000: ; Disable all interrupts move #$...
- Wed Jul 15, 2015 2:12 am
- Forum: Mega/SegaCD
- Topic: Sega CD (US) BIOS Disassembly @ GitHub
- Replies: 7
- Views: 14332
Those of you who are watching the GitHub repo have probably noticed by now that I've put up code for two out of the three sub-CPU program modules. (The third one is the CD player application, which I'm not too concerned about for now since I want to make my own software. I'll get to it eventually.) ...
- Wed Jul 15, 2015 1:38 am
- Forum: Megadrive/Genesis
- Topic: Mapping Output Not Whats Expected
- Replies: 7
- Views: 5158
Hello and welcome, SegaDev! The problem seems to be a combination of my unfinished framework, some gaps in my teaching, and some confusion with the number of rows/columns in the map. I've expanded the rows/cols to 64x32 (you had 40x30 in there), and updated to the most recent version of my framewor...
- Tue Jul 07, 2015 2:55 am
- Forum: Mega/SegaCD
- Topic: Sega CD (US) BIOS Disassembly @ GitHub
- Replies: 7
- Views: 14332
Sega CD (US) BIOS Disassembly @ GitHub
Hi, SpritesMinders! As I mentioned in another thread, I few weeks ago I started working on a disassembly of the Sega CD 2.00w (US) BIOS. I'm happy to say that I'm ready to open up at least part of it to the community! It's still very raw at the moment, and there are probably more subroutines I haven...
- Thu Jul 02, 2015 3:36 pm
- Forum: Mega/SegaCD
- Topic: Is there a full/partial dissassembly of the Sega CD BIOS?
- Replies: 4
- Views: 11755
- Thu Jul 02, 2015 5:27 am
- Forum: Exodus
- Topic: Exodus 2.0 + Open Source Release
- Replies: 105
- Views: 309050
Oh, wow. I just noticed that Exodus got a big update, and it looks great! Can't wait to start debugging with it! One thing I can't figure out though, just from playing with the interface, is how to get the different panels/dashboards to auto-hide. I can get them to dock to the main window, but they ...
- Tue Apr 07, 2015 4:36 pm
- Forum: Mega/SegaCD
- Topic: SegaCD debugging emulator?
- Replies: 12
- Views: 19134
- Thu Mar 26, 2015 11:00 pm
- Forum: Mega/SegaCD
- Topic: SegaCD debugging emulator?
- Replies: 12
- Views: 19134
SegaCD debugging emulator?
I'm putting the finishing touches on the framework for my first Sega homebrew, and I'm thinking I'd like to move it over to the SegaCD platform because it'll be easier to test that on actual hardware compared to finding dev cartridges for a normal Genesis ROM. I've read through the Rex Sabio docs on...