Amiga CD32

[akeley]

Well, if it could be made to work in some non complicated manner (like a custom ROM) it'd be interesting option, even without CD Audio.

There are about 130 CD32 + 24 CDTV games available as WHDLoad or hdfs, guess that covers the most important/popular ones. I think most lack the CD32-specific music and voice as well though.

[Caldor]

Well, if it could be made to work in some non complicated manner (like a custom ROM) it'd be interesting option, even without CD Audio.

There are about 130 CD32 + 24 CDTV games available as WHDLoad or hdfs, guess that covers the most important/popular ones. I think most lack the CD32-specific music and voice as well though.

Yes, the interesting games I think, are games like Simon the Sorcerer with voice and Beneath a Steel Sky with voice. Although they can both just be played with ScummVM of course, but those two games I do not think have a WHDLoad version, because of their size.

There is Heart of the Alien, a conversion of the MegaCD release to the Amiga which can also be played this way, but it should have a regular disk install release. It is the sequel to Another World.

Hmmm, Microcosm also seems to not have a WHDLoad version, so this would help with that game as well.

Defender of the Crown 2 does seem to have a WHDLoad version, but I wonder how that works, given it has voices for the game. It also has CD audio and reading up on the WHDLoad version it seems some scenes rely on waiting for CD audio to finish playing for a scene to end... so I guess the WHDLoad version might not fully work? This would have that same problem with this method of playing it though since we would still lack the CD audio.
https://whdload.de/games/DefenderOfTheCrown2.html

But overall, I just think it would be nice to have an easy way of playing CD based Amiga games. For some reason many of the CD32 collections that have been made does not seem to work with the Squirrel CD32 boot disk. Not sure why, but maybe I can find a solution for that as well. Much of the "emulation" is simply based on fixing the boot sequence based on a bunch of logical statements,

[Moondandy]

So we have the CD32 schematics here, but there are none here for CD-TV which is a milestone on the way to CD32 support.
https://www.amigawiki.org/doku.php?id=e ... schematics

Does anyone have, or know where to find CD-TV schematics?

Update: got them!
https://gamesx.com/wiki/lib/exe/fetch.p ... matics.pdf

[akeley]

Defender of the Crown 2 does seem to have a WHDLoad version, but I wonder how that works, given it has voices for the game. It also has CD audio and reading up on the WHDLoad version it seems some scenes rely on waiting for CD audio to finish playing for a scene to end... so I guess the WHDLoad version might not fully work? This would have that same problem with this method of playing it though since we would still lack the CD audio.

DotC is one of my favourite games and so I've tried this version some time ago. Yes, it's quite mute, I guess all these WHDL versions of CD32 games which had actual CD content are kinda "rips" (some actually say "no voice" or "no music" in the name). Maybe the other WHDL versions are "complete" because I don't think all CD32 games had extra CD features, they were just A500/1200 games on a CD (but I might have that wrong, not a big expert on these CD based Amigas).


@Moondandy: I found a CDTV service manual in my docs, attached here, there are some schematics inside but not sure if this is what you're looking for.

[Moondandy]

Thanks dude, much appreciated!

[Caldor]

Defender of the Crown 2 does seem to have a WHDLoad version, but I wonder how that works, given it has voices for the game. It also has CD audio and reading up on the WHDLoad version it seems some scenes rely on waiting for CD audio to finish playing for a scene to end... so I guess the WHDLoad version might not fully work? This would have that same problem with this method of playing it though since we would still lack the CD audio.

DotC is one of my favourite games and so I've tried this version some time ago. Yes, it's quite mute, I guess all these WHDL versions of CD32 games which had actual CD content are kinda "rips" (some actually say "no voice" or "no music" in the name). Maybe the other WHDL versions are "complete" because I don't think all CD32 games had extra CD features, they were just A500/1200 games on a CD (but I might have that wrong, not a big expert on these CD based Amigas).


@Moondandy: I found a CDTV service manual in my docs, attached here, there are some schematics inside but not sure if this is what you're looking for.

I think many CD32 games did not use CD audio because they did not have to, like Simon the Sorcerer CD32, had full voice audio, and I only think that was possible because it could use more compressed audio than CD audio would be. Its just raw wave data after all. A full CD had some 60-74 minutes of CD audio. So about 10mb of CD space would be 1 minute of audio.

There are CD32 games that use CD audio tracks though.

[Caldor]

I have been experimenting some more. I have made some boot disks and boot roms even, that use the MiSTer shared folder to save games... and saving the games does work. But loading the games again does not work though. I was wondering why but someone told me it might be because some of file properties on the shared folder might get lost due to not being an AmigaDOS file system, which tend to support longer file names and more, and I am guessing there is a file property that the FatEX filesystem does not have, because it should not be the length of the filenames that is the problem.

On the AO486 core, the shared folder was made a lot more compatible by telling the core that the shared folder was a 2gb drive. I guess something similar might be done with the MiSTerFileSystem for the Amiga core.

Another option is putting some image on the shared folder that would then be mounted and used to store the save games. To keep the CD32 boot rom as standalone as possible, I would hope to find a way to create an HDF or ADF image with a script, format it and mount it as needed. Making it some initial process.

The much simpler solution however, would be to require a floppy to be mounted in DF0 for it to save to. I am also trying to compare different CD file systems to see which might be the most compatible for different games.

I have 3 different CD32 emulation methods. SimCD32, SquirrelSCSI CD32 and IDEfix CD32. IDEfix has a special filesystem it uses for CDs, and SimCD32 even has a special CD.device it uses, and I guess SquirrelSCSI does as well. It seems atapi.device might also be compatible with the MiSTer CD drive. So I will try to experiment with different combinations to see what is the most compatible.

There is also an FPGA developer that contacted me, interested in trying to get CD32 support for the MiSTer. He is working on other cores as well though. so I will be focusing on the emulation for now. But getting CD audio support is something I think SquirrelCD32 would support.

One of the games I use to test with is Simon the Sorcerer CD32, and it seems the voice quality varies with different emulation types. So sometimes sentences get cut off. Anyone know why that might be and if there is a way to fix that? I do think it happens on my Amiga CD32 as well.

[KremlingKuthroat19]

Thanks for your extensive work on CD32 Caldor! It's great that an FPGA developer is interested in adding CD32 support to the existing core.

[Caldor]

Thanks for your extensive work on CD32 Caldor! It's great that an FPGA developer is interested in adding CD32 support to the existing core.

Yes, that is pretty exciting. I hope we will see something come from it soon. Could be pretty awesome having CDTV and CD32 support for the MiSTer I think. Might take a while though before there is anything tangible from this.

I still have one idea for the CD32 emulation to try, which is to try an older version of the MiSTer Main and Core, because I am pretty sure it used to be slightly better... or at least it used to be possible to use SquirrelCD32 with a regular Kickstart 3.1 ROM. But I am not sure what version I should try and how far back. Also I suspect I should probably use a different SD card to ensure there wont be Linux subsystem conflicts. It might help with the development if there is something with how the CD drives work for the MiSTer that might cause compatibility problems in the Amiga core.

[lomdar67]

There is also an FPGA developer that contacted me, interested in trying to get CD32 support for the MiSTer. He is working on other cores as well though.

Any update on this?

[Caldor]

There is also an FPGA developer that contacted me, interested in trying to get CD32 support for the MiSTer. He is working on other cores as well though.

Any update on this?

No, it has been pretty quiet. There was a release of the Minimig core on the TC64 though that adds CD support, with CD audio from what I could find.

That might get ported to the MiSTer I guess... we can hope

[Apollon]

Hi guys, I'm Apollon from the A1K forum and a big CD32 fan, a possibility to have a CD32 system with strong 68020s and ODE possibility is stunning. So the Mister could behave like a real CD32 with TF330, without the disadvantages of a mechanical CD drive. There are some games I really like to play with CD audio.

I would be very interested to know how far the CD32 replica has come?

[Malor]

I haven't heard that anyone is working on it, and I'm pretty sure there's no CD audio available on the regular 1200 emulation. CDs are working, but not the audio AFAIK.

CD32 may never happen; someone has to be both interested in the project and skilled enough to do it, and nobody seems to have showed up yet.

I've never tried, but it's probably doable with WinUAE. It has a special 'beam racing' mode that reduces latency a bunch compared to regular software emulation, so it would probably do a pretty acceptable job. And it explicitly lists the CD32 as a supported model.

[Caldor]

I think the TC68 Amiga core had CD audio support added to it, but it has not been ported to the MiSTer Amiga core yet.

[Guich]

First of all, big thanks to Caldor for your very useful tutorial. Everything works perfectly. I have a CDTV and an Amiga 2000 and I would like to recreate the same system on my Mister withe ISOs support. I would like the kickstar to start with animation and, if the cd was inserted in the primary slave, it would boot the startup sequence of the cd, or exit the cdtv menu and load the hdf workbench. I made a custom rom kickstart 1.3 with scsi support for the hard disk, file system for mister, loaded the share folder, and also mounted two virtual floppy drives with the Mimic application. Everything OK. The problem is that i can't load the CD0. (The hard disk has two partitions of 1Gb each, formatted PSF3. Workbench is 1.3.3 rev. 34.34; SCSI.device Is version 40.12). I also made a second custom rom with CDTV extende 2.35. I noticed that on WinUAE it works perfectly. CDTV animation, read the cd, boot the CDTV logo and then load the game. But not on the Mister.( I just got boot screen 1.3 with floppy request or boot to hdf and workbech if inserted). Assuming that the custom rom works, how do I mount the CD0? What driver and filesystem should I use? Any suggestions. I probably made a big mess and I don't know how to fix It... I'm becoming crazy

[Caldor]

I have made that CDTV 2.35 as well. I think the problem is the CDTV is based on SCSI, and the MiSTer Minimig core only has IDE.

With emulation similar to the Amiga CD32 emulation it should be possible to boot at least from ISO images in some CDTV games. Some of the boot floppies for CDTV does work, but you will have to set the core to run with the 68000 CPU and not the 68020, because that seems to be one of the things CDTV games are looking for.

I suspect its the copy protection in the CDTV maybe that checks for the CPU type, but might also just be the emulator thing running CDTV that checks for it, because at least the 2.35 ROM should allow for 68030... which I guess might not be enough for it to also accept 68020.

Would be very nice to be able to use the 2.35 ROM on the Amiga core, but I think it would require so many changes to it that it would become its own branch of the core, to be able to support all the CDTV specific features and hardware. SCSI, CD drive and... I think there are some other things as well.

I am pretty sure it should be possible to make a custom ROM that could support all of this, but my attempts at making a custom ROM that would accept CD images in the shared folder so far failed and I have been hoping to first see some changes made to the core that would help add more CD32 support and CDTV.

[rhester72]

I'm not aware of any copy protection whatsoever in CDTV.

[Malor]

The Wikipedia article on the CDTV leads to the article on the A570, which was an external drive unit for the A500. That unit apparently allowed for CDTV compatibility, where third-party CD drives, IDE or SCSI, did not, so Commodore was definitely doing something weird with the interface.

The article says this:

The A570 had no need for drivers. It was automatically recognized as a standard Amiga expansion card by the Amiga Zorro bus Autoconfig feature. Programs for playing Audio CDs were available on a bundled 'A570 Tools' floppy disk, public domain software disk collections, and then on Aminet.

So apparently CDTV games and programs were poking hardware directly in some fashion. It sounds like a real mess.

[Caldor]

I'm not aware of any copy protection whatsoever in CDTV.

Its described here:
https://cdtvland.com/os235/

"Waaay back in the early 1990s, when CDTV launched, Commodore decided that only registered CDTV developers who paid a licensing fee and royalties were allowed to create bootable CD-ROMs. This was “enforced” by requiring the presence of a special file (named CDTV.tm) on the CD-ROM for it to be bootable. This file contains copyrighted code and the trademarked CDTV logo. Including this file on a CD-ROM without owning a license would technically be breach of copyright. While necessary back in the early 1990s when CDTV was an economically viable platform, today it is nothing more than an unnecessary technical hurdle for CDTV users who just want to author bootable CD-Rs for personal use on their CDTV player."

I am not sure its that much of a copy protection thing, but for no good reason the CDTV looks for the CDTV.tm file or it wont boot. Part of what the 2.35 ROM update, a custom ROM made by the community, does is removing that silly check which was part of why it was so tedious to try to create custom CDTV CDs. Many have still done it though, with the CDTV.tm file and everything. I guess its not so much for preventing the CD being copied as it is to ensure that the ones making the CD has the official tools for making CDTV CDs.

But yeah, there are also some hardware checks I think. Which is also not really copy protection I guess, but more that the hardware is expected to be there.

[rhester72]

I read the article you referenced, but the problem is the A570 (and many software solutions that came later) which don't seem to require the license to be present at all. I suppose it's possible it was only on true CDTV hardware, but it would seem more than pointless given the A570 was quite literally intended to turn an Amiga 500 into a CDTV.

[Caldor]

I read the article you referenced, but the problem is the A570 (and many software solutions that came later) which don't seem to require the license to be present at all. I suppose it's possible it was only on true CDTV hardware, but it would seem more than pointless given the A570 was quite literally intended to turn an Amiga 500 into a CDTV.

Should be the same with the A570:
http://eab.abime.net/showthread.php?t=53936&styleid=4

Not sure if there might be other kickroms that might bypass the CDTV.tm requirements that works with A570, but it should require it.

[rhester72]

Sorry, I wasn't referring to autoboot - obviously the A500 won't, given it predates CD-ROM technology, without some serious help. LOL

[Malor]

A500s supported autoboot from Kickstart 1.3 forward. Before that, booting from floppy was the only option, but 1.3 allowed you to boot from pretty much any arbitrary device that supported the concept, including the recoverable RAM disks that started to appear around then. So it should support autoboot from the CDTV. The fundamental capability is definitely there; booting from a hard drive on an A500 or A2000 was dead simple.

How it actually works, however, is something I've never learned. I don't know if the CDTV requires a certain ROM revision, or if it provides its own ROM. Devices could do this, so an onboard CDTV ROM that loaded into RAM and then demanded the CDTV.tm file is one possibility.

Since the A570 was intended to retrofit CDTV capabilities to a regular A500, I assume that's probably how it worked. Actual CDTVs could well have had the requirement in the console ROM, but A570s probably had to autoload a custom driver, so that's probably the ROM that would need patching.

Much of this post is speculation, treat it accordingly. Commodore could have done all kinds of crazy stuff; AmigaOS was super flexible.

edit with one example: they could have required Kickstart 2.0 or later, which could easily have the CDTV.tm requirement embedded.

[rhester72]

1.2 actually supported autoboot but it didn't work due to a very subtle bug that was fixed in 1.3. As the VAST majority of A500s shipped with 1.2, there was no assumption on the part of the makers of the A570 that it would work in that fashion.

It's not magic, all it requires is simple of the analysis of the CDTV ROMs. I've added it to my to-do list of projects...but it's very long, so take that for what it is. =) I'm quite intellectually interested now, as this is certainly the first I've ever heard of CDTV licensing (and I'm quite certain Walnut Creek didn't know!).

For the record, CDTV-CR actually did intend to use 2.04.

[Malor]

1.2 actually supported autoboot but it didn't work due to a very subtle bug that was fixed in 1.3. As the VAST majority of A500s shipped with 1.2, there was no assumption on the part of the makers of the A570 that it would work in that fashion.

I don't have the knowledge to directly comment about that, but autoboot didn't work in 1.2, whether it was intended to or not, so if the CDTV was intended to work with 1.2, they would have needed to do something tricky with its ROMs.

It's not magic, all it requires is simple of the analysis of the CDTV ROMs. I've added it to my to-do list of projects...but it's very long, so take that for what it is. =) I'm quite intellectually interested now, as this is certainly the first I've ever heard of CDTV licensing (and I'm quite certain Walnut Creek didn't know!).

I'm unclear on who Walnut Creek refers to?

I could probably learn how to read the ROMs, since I've worked a little bit with 68000 assembly, but wouldn't bother unless it somehow helped with the CD32 port. I believe that's blocked on completing the Akiko chip, which I can't help with at all. Understanding the CDTV ROMs looks like a moderately fun but irrelevant tangent.

[FPGA64]

Most A500 were Kickstart 1.3. 1.2 was around for just a year of the A500 and was rapidly displaced by the 1.3 500's

[rhester72]

Most A500 were Kickstart 1.3. 1.2 was around for just a year of the A500 and was rapidly displaced by the 1.3 500's

In Europe, perhaps, but definitely not in the US. The VAST majority of US-sold models were 1.2 (but obviously upgradable).

[rhester72]

I'm unclear on who Walnut Creek refers to?

They created a good bit of "unlicensed" CDTV content sold in the US.

I could probably learn how to read the ROMs, since I've worked a little bit with 68000 assembly, but wouldn't bother unless it somehow helped with the CD32 port. I believe that's blocked on completing the Akiko chip, which I can't help with at all. Understanding the CDTV ROMs looks like a moderately fun but irrelevant tangent.

Oh, that's the only purpose of it for me - as an interesting intellectual tangent. Never heard of CDTV 'copy protection' before and keen on seeing how it's used (and why).

[Caldor]

I'm unclear on who Walnut Creek refers to?

They created a good bit of "unlicensed" CDTV content sold in the US.

I could probably learn how to read the ROMs, since I've worked a little bit with 68000 assembly, but wouldn't bother unless it somehow helped with the CD32 port. I believe that's blocked on completing the Akiko chip, which I can't help with at all. Understanding the CDTV ROMs looks like a moderately fun but irrelevant tangent.

Oh, that's the only purpose of it for me - as an interesting intellectual tangent. Never heard of CDTV 'copy protection' before and keen on seeing how it's used (and why).

The Akiko chip in the CD32 is rarely used by anything. Except make the Akiko do chunky2planar... often used in 2.5D games, but the MiSTer already supports that part of Akiko.

This is why CD32 games can be emulated on the Amiga 1200. Some claim that Microcosm uses Akiko, but it does not seem it does. But, I guess Akiko might be used for the CD part, which I guess a CD32 emulator on the A1200 wont need. So a CD32 core might need Akiko for more games than the Amiga 1200 would using emulation.

[FPGA64]

Akiko was responsible for controlling the CD drive in the CD32 as well as being the controller for the Keyboard and serial. The Chunky 2 planar part wasnt used much if at all. The CD32 was a commercial flop and so no one would spend the time to develop for a niche machine when you could just crank out a A1200 game