Search found 15 matches

by F1ReB4LL
Mon Jun 17, 2019 11:44 am
Forum: Mega/SegaCD
Topic: Bike shedding a new CD-ROM format
Replies: 20
Views: 1342

Re: Bike shedding a new CD-ROM format

CD+G discs must be ripped from drives that can read subchannel data. Multiple reads, preferably from multiple discs and multiple drives, should be done to reduce errors as much as possible. Unfortunately, there's no guaranteed way to read it because the CD-ROM standard designers stupidly didn't inc...
by F1ReB4LL
Fri Jun 14, 2019 12:14 pm
Forum: Mega/SegaCD
Topic: Bike shedding a new CD-ROM format
Replies: 20
Views: 1342

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. It's not. The idea is good, the format itself is terrible. It needs a BCD image inside to be the proper MAME-grade format; right now it doesn't even have a proper TOC inside, let alone lea...
by F1ReB4LL
Sun May 19, 2019 11:56 pm
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 112
Views: 7168

Re: Questions on writing a new Mega CD emulator

It mostly details things like minimum LBA, the ISO9660 filesystems, sector frame sizes - all standard CDROM stuff. The only really Saturn specific stuff is the code you have to put in sectors 0-15, but those are well known. I've actually hoped to see something similar to the "GD-ROM Format Specific...
by F1ReB4LL
Fri May 10, 2019 11:01 am
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 112
Views: 7168

Re: Questions on writing a new Mega CD emulator

Mega CD specification doc is nice. No official Saturn CD format specification around, btw?
by F1ReB4LL
Tue May 07, 2019 11:37 am
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 112
Views: 7168

Re: Questions on writing a new Mega CD emulator

Btw, is anyone familiar with the LibreDrive hacked firmwares? Is it possible to use them not only for ripping the movies from DVDs/BDs, but to read the entire CD/DVD/BD contents?
by F1ReB4LL
Mon May 06, 2019 4:10 pm
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 112
Views: 7168

Re: Questions on writing a new Mega CD emulator

Take the FDS: the images on the internet are all stripped down, removed of all gaps and block start markers. But you need this data to simulate the seek delays to read data. Then they try to zero out the save files on the disks. The result is an image with a known SHA256 hash, but not one usable in...
by F1ReB4LL
Mon May 06, 2019 7:08 am
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 112
Views: 7168

Re: Questions on writing a new Mega CD emulator

I was speaking about the reason for storing them scrambled in a cd image file, which I thought was what byuu was asking about Ah, missed the point. Yeah, the dumps should be as unaltered as possible. And it raises another question: should the subchannels be stored in the deinterleaved or in the int...
by F1ReB4LL
Sun May 05, 2019 1:22 pm
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 112
Views: 7168

Re: Questions on writing a new Mega CD emulator

Hmmm, that data has been encoded as scrambled. Want to see what it looks like descrambled? Yeah, forgot to descramble it (the data is dumped as scrambled by default to avoid the forced descrambling & data altering by the drive's firmware). http://forum.redump.org/topic/3367/sega-saturn-cp-talk/ -- ...
by F1ReB4LL
Sat May 04, 2019 5:26 pm
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 112
Views: 7168

Re: Questions on writing a new Mega CD emulator

If you can get three or more rips of each disk (preferably more like five or six), you can reconcile these errors and cancel them out, to get a true image of the disk as it really is, apart from surface damage or smudges on the disk surface that are interfering that is. If you can get three or more...
by F1ReB4LL
Fri May 03, 2019 11:55 pm
Forum: Mega/SegaCD
Topic: Questions on writing a new Mega CD emulator
Replies: 112
Views: 7168

Re: Questions on writing a new Mega CD emulator

The next level down from this that I consider "valid" is to store data with the frames decoded and PQ error correction already performed, but with mode 1 sectors still scrambled and ECC/EDC correction not yet applied, and the subchannel data retained. All that you've done here is to decode the fram...
by F1ReB4LL
Wed May 07, 2008 4:17 pm
Forum: Regen
Topic: Old Regen pages
Replies: 547
Views: 254386

I'm not sure that VSync will work with TV-out. 800x600 can be displayed through TV out, but it can't be displayed with TV timings directly. 640x480 and 800x600 are perfect, 720x576 is glitchy with vsync, but other emus work fine in this resolution - Fusion, Nestopia, psx emus, etc. (those, which su...
by F1ReB4LL
Tue May 06, 2008 3:56 pm
Forum: Regen
Topic: Old Regen pages
Replies: 547
Views: 254386

Shiru wrote:It's very likely that it will be not multiple of 50 Hz, because only CRT monitors have 100 or 150 Hz refresh rate. Very likely that Windows sets 75 or 85 Hz which is much more common.
PAL TVs usually have 50 Hz exactly :) I'm talking about PAL TV on TV Out.
by F1ReB4LL
Mon May 05, 2008 10:18 pm
Forum: Regen
Topic: Old Regen pages
Replies: 547
Views: 254386

AamirM wrote:IIRC, Windows changes the refresh rate on changing the resolution, so if it sets the refresh rate that is not a multiple of 50 Hz (for PAL) the syncing will be wrong.
lol, it can't be "not a multiple of 50 Hz", because it's a PAL signal for TV (not PAL60) :)
by F1ReB4LL
Mon Apr 28, 2008 8:28 pm
Forum: Regen
Topic: Old Regen pages
Replies: 547
Views: 254386

Running PAL games on a PAL TV (through the TV-Out) with VSync cause major slowdowns, NTSC games on a NTSC TV with VSync work fine, though. PAL games work fine with VSync in Fusion, other emulators also work fine in PAL with VSync (Nestopia, pSX, etc.) -- something wrong with the PAL refresh rate in...
by F1ReB4LL
Thu Apr 24, 2008 6:53 pm
Forum: Regen
Topic: Old Regen pages
Replies: 547
Views: 254386

Thunder Force IV (Europe) -- black screen Ultimate Mortal Kombat 3 (Europe) -- black screen Running PAL games on a PAL TV (through the TV-Out) with VSync cause major slowdowns, NTSC games on a NTSC TV with VSync work fine, though. PAL games work fine with VSync in Fusion, other emulators also work f...