Search found 591 matches

by Mask of Destiny
Fri May 31, 2019 8:14 pm
Forum: Mega/SegaCD
Topic: Bike shedding a new CD-ROM format
Replies: 20
Views: 2165

Re: Bike shedding a new CD-ROM format

I can't find good documentation on what CHD actually does with CDs. So in it's most basic form a CHD is a series of compressed "hunks" of data. Hunks are relatively small (512KB max supposedly) and are compressed individually to allow reasonably random access. For CDs, extra metadata is stored to h...
by Mask of Destiny
Thu May 30, 2019 9:32 pm
Forum: Mega/SegaCD
Topic: Bike shedding a new CD-ROM format
Replies: 20
Views: 2165

Re: Bike shedding a new CD-ROM format

For most "normal" CD-ROM imaging needs, I kind of feel like MAME's CHD format is probably the right way to go. The lack of proper documentation is a bummer, but it handles multi-track data well and can store raw F1 frames + subcode data. It also supports lossless compression of tracks including FLAC...
by Mask of Destiny
Sun Apr 28, 2019 4:06 pm
Forum: Megadrive/Genesis
Topic: Z80 bus + I/O mapping redux
Replies: 7
Views: 1298

Re: Z80 bus + I/O mapping redux

As promised, here's that test ROM and here's the source . * a00000-a0ffff => [8-bit bus] Z80 (A15 is ignored) So this is actually a funny one. On the 68K side, all 16 data lines are connected (via the IO chip because apparently they ran out of pins on the bus arbiter, lol), but the bus being connect...
by Mask of Destiny
Fri Apr 26, 2019 3:18 pm
Forum: Megadrive/Genesis
Topic: Z80 bus + I/O mapping redux
Replies: 7
Views: 1298

Re: Z80 bus + I/O mapping redux

bgvanbur states the Z80 can write to 68K main-CPU RAM (e00000-ffffff), but reads return 0xff. It's further comments that reads return different values on different systems. Stef finds that writes do not work. Steve Snake says they used to on the earliest models. For what it's worth, I have a test R...
by Mask of Destiny
Wed Apr 24, 2019 4:21 pm
Forum: Demos
Topic: MD-NICCC - a 3D Mega Drive experience by TiTAN
Replies: 56
Views: 6387

Re: MD-NICCC - a 3D Mega Drive experience by TiTAN

Stef wrote:
Wed Apr 24, 2019 2:40 pm
Are you speaking about Starfox on SNES or something else ?
Pretty sure Sik is talking about the SNES port of the ST-NICC demo which was also released at Revision this year.
by Mask of Destiny
Fri Apr 05, 2019 9:59 pm
Forum: Demos
Topic: Tänzer, a "ninja" game (Dev Diary thread)
Replies: 290
Views: 39104

Re: Tänzer, a "ninja" game (Dev Diary thread)

notaz, what revision is your MD1?
by Mask of Destiny
Wed Apr 03, 2019 6:44 pm
Forum: Cartridge
Topic: EEPROM mapping for homebrew
Replies: 9
Views: 1172

Re: EEPROM mapping for homebrew

My 2 cents: standardizing the mapping (i.e. which address and which I2C bits are connected where) is good, but I think allowing the size to be specified in the header is desirable. It might make sense to pick a single "mode" (i.e. how the address is sent), but from my perspective supporting any of t...
by Mask of Destiny
Thu Mar 28, 2019 5:21 pm
Forum: Tools
Topic: BlastEm 0.6.0
Replies: 15
Views: 2821

Re: BlastEm 0.6.0

Hello folks, I've released the next version in the 0.6.X series: BlastEm 0.6.2 . The most notable change for developers is that I have fixed a regression in GDB remote debugging support on Linux and other Unix-like systems (Windows was not affected AFAIK). There are also some small accuracy fixes an...
by Mask of Destiny
Mon Feb 11, 2019 6:48 pm
Forum: Blabla
Topic: 68000 Arcade systems programming
Replies: 14
Views: 2136

Re: 68000 Arcade systems programming

They're not on his site anymore, but Charles MacDonald actually wrote docs describing various Sega Arcade boards and they are archived at various places:
Pre-System 16
System 16B
System 18
System C2
X-Board
System 24
by Mask of Destiny
Sun Jan 27, 2019 3:45 am
Forum: Tools
Topic: BlastEm 0.6.0
Replies: 15
Views: 2821

Re: BlastEm 0.6.0

Cool. Yeah, that definitely finds the rom.db. It's probably how I built the project, but it doesn't actually show anything when I run a rom. I get a blank screen and the following error: "Failed to open shader file default.v.glsl for reading" Shaders are expected to be in the "sharers" subdirectory...
by Mask of Destiny
Thu Jan 24, 2019 10:00 pm
Forum: Tools
Topic: BlastEm 0.6.0
Replies: 15
Views: 2821

Re: BlastEm 0.6.0

Sounds good, I'll give it a go later on. BTW, love the debugging modes on this. This should be very handy! Glad you like them. I have pushed some changes to allow for building a more standard filesystem hierarchy friendly binary. If you want to try it out, grab tip from the repo and build with the ...
by Mask of Destiny
Mon Jan 14, 2019 8:47 pm
Forum: Tools
Topic: BlastEm 0.6.0
Replies: 15
Views: 2821

Re: BlastEm 0.6.0

Installing in Linux is kind of awkward, since it is not looking in standard locations for config files. /etc/, ~ (according to README). The location of blastem.cfg is standard for a per-user config file. It is true that my tarball is a self-contained package rather than something that's designed to...
by Mask of Destiny
Mon Jan 07, 2019 6:30 pm
Forum: Tools
Topic: BlastEm 0.6.0
Replies: 15
Views: 2821

Re: BlastEm 0.6.0

There's only one little issue for me with it: checkboxes look like they mean the opposite they should, ie. a black checkbox means "enabled", which seems odd. Yeah, the default checkbox style is one of my biggest beefs with Nuklear. I'll have to see if there are any easy tweaks that can make it a bi...
by Mask of Destiny
Sat Jan 05, 2019 9:09 pm
Forum: Megadrive/Genesis
Topic: 68K inner workings
Replies: 3
Views: 1380

Re: 68K inner workings

Have you had a look at the 68K patents? Looks like you've managed to figure out a lot from the schematic, but the US4325121 patent specifically has a lot of information about how the microcode/nanocode works and includes micro/nanocode listings for a pre-release version of the processor which might ...
by Mask of Destiny
Fri Jan 04, 2019 6:04 pm
Forum: Tools
Topic: BlastEm 0.6.0
Replies: 15
Views: 2821

Re: BlastEm 0.6.0

v0.6.0 ended up being kind of buggy due to an abbreviated QA cycle. v0.6.1 fixes a number of issues and is now available here