Author Topic: Any chance of a CDROM2 unit on an FPGA?  (Read 1336 times)

MottZilla

  • Full Member
  • ***
  • Posts: 192
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #45 on: August 12, 2012, 10:40:10 AM »
Patching the 3.0 Japanese BIOS would make the most sense as it has the greatest compatibility. But you could probably patch other versions too since alot of what you would be doing would apply to other versions too.

I'm not sure what you mean by an IDE converter. You mean the idea would be to replace the drive with an IDE CD-ROM? Anyway, I agree Drakon. Eventually if someone with the skills and knowledge required becomes interested, it surely can be done.

BlueBMW

  • Hero Member
  • *****
  • Posts: 4346
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #46 on: August 12, 2012, 11:32:51 AM »
My understanding is that the Turbo / PCE CDROM is on the hardware level just a scsi drive.  Surely an interface can be made.
[Sun 23:29] <Tatsujin> we have hard off, book off, house off, sports off, baby off, clothes off, jerk off, piss off etc

TheOldMan

  • Hero Member
  • *****
  • Posts: 958
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #47 on: August 12, 2012, 12:14:06 PM »
Quote
I'm not sure what you mean by an IDE converter. You mean the idea would be to replace the drive with an IDE CD-ROM?
Quote
My understanding is that the Turbo / PCE CDROM is on the hardware level just a scsi drive.  Surely an interface can be made.

AFAIK, the cd-rom -is- a scsi device. Since IDE is a stripped-down version of SCSI, I figured it wouldn't be too hard to develope a replacement interface.
I've thought about this quite a bit. I'm no electronics expert, but it seems like it would be doable.

If you have serious skills developing electronic projects, I would be willing to discuss how -I- would approach it. It just might surprise you.....But it's not something I'm comfortable discussing publicly.

spenoza

  • Hero Member
  • *****
  • Posts: 2751
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #48 on: August 12, 2012, 12:26:40 PM »
But why IDE? Why not simply an SD card interface? SCSI and SD cards both use a serial standard. Surely that wouldn't be difficult either.
<a href="http://www.pcedaisakusen.net/2/34/103/show-collection.htm" class="bbc_link" target="_blank">My meager PC Engine Collection so far.</a><br><a href="https://www.pcenginefx.com/forums/" class="bbc_link" target="_blank">PC Engine Software Bible</a><br><a href="http://www.racketboy.com/forum/" c

BlueBMW

  • Hero Member
  • *****
  • Posts: 4346
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #49 on: August 12, 2012, 01:59:20 PM »
First step is to figure out the scsi interface of the cdrom.  Then we can convert it to IDE and beyond that toncompact flash, SD or SATA or whatever is necessary.
[Sun 23:29] <Tatsujin> we have hard off, book off, house off, sports off, baby off, clothes off, jerk off, piss off etc

Drakon

  • Sr. Member
  • ****
  • Posts: 412
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #50 on: August 12, 2012, 03:09:58 PM »
But why IDE? Why not simply an SD card interface? SCSI and SD cards both use a serial standard. Surely that wouldn't be difficult either.

It would probably be the easiest.  IDE to compact flash adapters are very common.  Then you'd just need a ram chip or two and you'd be rockin'.  I still think a fpga would be a great idea because it'll make it easier to get the signal timing precise.  At first I was skeptical about fpga but when one of my first clients mailed me his nes powerpak I quickly learned how amazing the hardware is.
« Last Edit: August 12, 2012, 03:11:46 PM by Drakon »
http://16bitgamer.forumotion.ca/

NightWolve: "I'd say ole XGay fears another relapse, hence the need for strong, daily hetero reinforcement on his desktop. ;)"

Jibbajaba: "The problem with trying to flame Regal is that it's like trying to gut-punch a really fat person."

HercTNT

  • Hero Member
  • *****
  • Posts: 1460
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #51 on: August 12, 2012, 03:11:23 PM »
well stop talking about it and do it. my gt need iso's to play

Drakon

  • Sr. Member
  • ****
  • Posts: 412
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #52 on: August 12, 2012, 03:13:26 PM »
well stop talking about it and do it. my gt need iso's to play

I've got a bunch of commissions plus I'm too lazy to spend the time to learn how to work a fpga.  Maybe down the road.  Today I managed to build an amp that brings scart rgb up to arcade moniter level and I also learned how to mix audio signals together so small steps I say!

Tiido could probably make something like that but he's got his hands full with projects too.  I'll mention it to him next time he's online and I remember about it.
http://16bitgamer.forumotion.ca/

NightWolve: "I'd say ole XGay fears another relapse, hence the need for strong, daily hetero reinforcement on his desktop. ;)"

Jibbajaba: "The problem with trying to flame Regal is that it's like trying to gut-punch a really fat person."

TheOldMan

  • Hero Member
  • *****
  • Posts: 958
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #53 on: August 12, 2012, 04:05:24 PM »
Quote
SCSI and SD cards both use a serial standard.

Ah, spenoza...always good for a laugh. google scsi and hit the wikipedia article. Scsi didn't go serial until lately....
In 1989, it was SCSI-1, parallel all the way. (Yes, I remember those days. Still have my adaptec cards.)

wilykat

  • Hero Member
  • *****
  • Posts: 908
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #54 on: August 12, 2012, 04:23:36 PM »
Quote
SCSI and SD cards both use a serial standard.

Ah, spenoza...always good for a laugh. google scsi and hit the wikipedia article. Scsi didn't go serial until lately....
In 1989, it was SCSI-1, parallel all the way. (Yes, I remember those days. Still have my adaptec cards.)


Still got my old Macintosh and external hard drive.  Back then adding multiple SCSI devices can make or break noob easily.  Getting termination done right (gotta check for hidden built in terminator), ID conflict, orders of the device (scanner last or else hard drive may not work), and quality of the cable used to matter if you wanted more than one external device.

My last SCSI based Mac was a Power PC 9600 which has two SCSI controller for maximum of 14 extra devices (7 internal only + 7 internal or external)

Anyway back to the topic. Wouldn't it be easier to use CD base for TG-16 and PCE and use the little connector where CD-ROM plugs in to try and make CD replacement device? Then we could have a choice of standard CD cards. Plus we retain the built in memory saves.

But if we're going to make a complete rebuild of the entire CD system with custom BIOS, I vote for a modified System 3.0 with Altered Beast support back in.  Why did Altered Beast not work on newer card anyway?

thesteve

  • Hero Member
  • *****
  • Posts: 2952
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #55 on: August 12, 2012, 04:57:45 PM »
remember scsi may be parallel, but CD is serial.
the redbook is handled from the drive, ADPCM from the IFU, everything else from the core

TheOldMan

  • Hero Member
  • *****
  • Posts: 958
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #56 on: August 12, 2012, 05:02:33 PM »
Quote
Wouldn't it be easier to use CD base for TG-16 and PCE and use the little connector where CD-ROM plugs in to try and make CD replacement device?
Two problems with that idea:
1) no one knows the pinout of the little connector, and trying to replicate it would be a pain.
2) If I'm not mistaken, all the scsi peripheral logic is built into the cd drive. I do remember NEC planned for the cd rom to be useable on a computer. (That's why I bought one originally)

All of which means, to me, that you would have to do a lot of work just to replace an optical drive with flash medium. Not to mention the serial-> parallel conversion.... (okay, maybe not a problem, but it seems to me most flash memory based stuff is serial...)

However, the pinout of the connector on the pce is known, and there is a way to connect to those pins. It might not be pretty, but it would work.

Quote
But if we're going to make a complete rebuild of the entire CD system with custom BIOS...
Almost right. A rebuild of the cd interface, with support for newer storage. No custom bios required :)
Since it would have an IDE connector, theoretically anything you could convert to IDE would work. Only thing new would be a way to read the filesystem on the attached device - and FAT32 isn't that hard to program....

Now, let me ask a serious question: Why all the concern over using an SD card?
Everyone seems to think that is the way to go...

spenoza

  • Hero Member
  • *****
  • Posts: 2751
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #57 on: August 12, 2012, 05:10:52 PM »
Derp, that's right. SATA is serial but SCSI is parallel. I had a Mac back in the day so I was use to sorting out ID conflicts and terminator crap. Luckily, I couldn't afford enough devices to every have a particularly long chain.

Frustrates me when I make little (big) mistakes like that because I know better. I know SCSI better than probably most of the people on the forum, and then I open my mouth and insert my foot.

Well, if you need a double speed SCSI CD-ROM drive, I think my parents still have their external Mac CD-ROM drive. Probably still works, too. It needed those cartridge trays. I played the hell outta Myst.
« Last Edit: August 13, 2012, 06:00:34 AM by spenoza »
<a href="http://www.pcedaisakusen.net/2/34/103/show-collection.htm" class="bbc_link" target="_blank">My meager PC Engine Collection so far.</a><br><a href="https://www.pcenginefx.com/forums/" class="bbc_link" target="_blank">PC Engine Software Bible</a><br><a href="http://www.racketboy.com/forum/" c

wilykat

  • Hero Member
  • *****
  • Posts: 908
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #58 on: August 12, 2012, 07:29:15 PM »

Now, let me ask a serious question: Why all the concern over using an SD card?
Everyone seems to think that is the way to go...


No idea. I wish someone would use Smart Media format as I got crap load of 16 and 32MB cards sitting around getting dust.

Seriously, I think it's mostly cost for us end users.  I can get a 32GB class 10 SD card for about $20 or Class 4 for $15 at a local Microcenter.  CF on the average costs more than twice the same sized SD card, and there's no real speed advantage with older consoles.  Plus SD is used more in many devices (phones, tablets, camera) while CF are largely confined to high end camera these day.

xD seems to be dying, I haven't seen any new devices that required xD card and I haven't seen new xD card at local store anymore.  Sony Memory sticks usually costs twice as much as SD and with many of Sony's camera supporting SD slot it almost looks like MS format may be going extinct within a few years. 

Some of us likely have spare SD laying around but I had to really dig my ancient bag o' camera relic to find a CF card for my PowerPak.  Even my local Walmart doesn't have CF card anymore.

Drakon

  • Sr. Member
  • ****
  • Posts: 412
Re: Any chance of a CDROM2 unit on an FPGA?
« Reply #59 on: August 13, 2012, 12:05:27 AM »
Ah, spenoza...always good for a laugh. google scsi and hit the wikipedia article. Scsi didn't go serial until lately....
In 1989, it was SCSI-1, parallel all the way. (Yes, I remember those days. Still have my adaptec cards.)

I'm pretty sure the whole idea behind serial is that there's very few wires needed.  Like sata, sd.

Now, let me ask a serious question: Why all the concern over using an SD card?
Everyone seems to think that is the way to go...

I blame krikzz for being obsessive over those little serial flash things.
« Last Edit: August 13, 2012, 12:09:00 AM by Drakon »
http://16bitgamer.forumotion.ca/

NightWolve: "I'd say ole XGay fears another relapse, hence the need for strong, daily hetero reinforcement on his desktop. ;)"

Jibbajaba: "The problem with trying to flame Regal is that it's like trying to gut-punch a really fat person."