PCEngineFans.com - The PC Engine and TurboGrafx-16 Community Forum
NEC PC-Engine/SuperGrafx => PC Engine/SuperGrafx Discussion => Topic started by: Everblue on August 08, 2012, 08:20:26 PM
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I have been out of touch with the PCE scene for a few years now, so I wondering if there is any project going on which lets you load ISOs off an FPGA or something similar to the Turbo Everdrive but for ISO? It seems we will eventually run out of CD replacement units at one point so I was wondering if anyone has came with alternative solution yet.
Thanks :mrgreen:
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That i'm aware of no such ability exists outside of emulators for handheld systems. Take the time though to see some of the amazing stuff forum members have created in the few years you have been away. The only thing some of the guys here have not figured out yet (besides what you asked), is how to install a wet bar into a turbo express. At the rate that thesteve and duo-r are going even that will be included within a few weeks :)
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I didn't mean for handheld systems, but for the normal PC Engine? =)
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If all games fully utilize the BIOS for loading data from CD-ROM, playing Audio, etc then you could probably rig up a device with a hacked BIOS to load images from fast enough media. If you used the expansion port you could mix in the base audio with the redbook audio and hopefully you'd implement the I think adpcm sound channel that was added by the CD system. On DUO systems it might be a bit more tricky and might require modding if not all the required signals are there.
I don't know of anyone working on any such project but it is possible. Also I would imagine that there is still a healthy supply of suitable replacement parts for repairing CD-ROMs for the PCE.
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So I guess I better get a CD-Rom solution and a PC Engine (which I still don't have!)
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EXACTRY!
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LOL o k... by the way is there anyone reliable on these boards to talk to for having a PC Engine modded for RGB with amp?
Cheers
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There's a few, but BlueBMW was supposed to be making some populated amps. Still waiting on that though.
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Well I need someone who can mod it for me as I cant even solder =)
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In the mods section there are a ton of guys that can help you out.
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Thanks... I'll ask there!
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So I guess I better get a CD-Rom solution and a PC Engine (which I still don't have!)
Well I'm not certain that you couldn't do it with just the HuCard slot. There is a fair chance that you could simulate the CD-ROM via BIOS changes and a new media like SD assisted with a FPGA or something else. The only thing I'm sure of is the DUO lacks any way to directly mix stereo audio with just the HuCard slot. You'd need to hookup to the AV's audio output and mix in the CD system audio.
The point is something could probably be cooked up. The bad thing is that it's less likely to be done when it is so easy to just fix your CD-ROM. But I'd certainly find it interesting if you could just plug something into the Hucard slot and actually run CD games off mass storage media. Maybe eventually it will happen. Also the PC-Engine + Briefcase CD-ROM system I've always thought was awesome looking.
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I'm still waiting for a PCE System on a Chip clone (PCEOAC. There are already free circuit markups and diagrams of the 6502 core, and every single piece of patentable hardware in the PCE or its peripherals should be no longer protected and in the clear. The trouble, of course, is sussing out the little dark corners of hardware functioning. Still, there are skilled enough folks in and around the community that with proper incentive we should probably be able to work something out.
The ideal PCEOAC, in my mind, would be a single chip solution that replicates all the functions of a SuperGrafx and the extra ADPCM chip from the CD unit, combined with an open BIOS that emulates the functions of the SCD BIOS (and possibly is switchable for different BIOS revision clones). It would have a card slot with an option to switch the data lines and ground pin. There would be an SD-Card slot and a separate chip that allows the system to use ISO images to emulate a CD-ROM, since that option would probably actually be cheaper and more reliable than trying to include an actual CD-drive.
The caveat? Even if this thing could be made (it is certainly technically possible, but there are many other barriers), it would probably be about as expensive as getting legit, original hardware. It would have to be made first using some kind of FPGA by some company like Alterra. I don't know that such a thing could ever be as popular as the NES/Genesis/SNES devices currently on the market, so it might never make it from FPGA to an actual mass-produced unit, meaning costs would be unlikely to come down.
The upside, of course, it that it would be good backup for aging hardware, and having those circuit and chip layouts finalized and in working order would help with keeping the community alive even as hardware slowly fails.
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The PCE doesn't use a 6502 though. Honestly if you have enough money, and it would be a lot, there is nothing stopping you from paying a company/lab to do the work to break it down and make it possible to clone it exactly. I want to see a DUO with SGX support and native S-Video & RGB output as well as Region Switching. That would be nice. But I don't know that we will ever see that. Something more likely is like those FireCore Genesis clones. Essentially it's a device that is just built to run an emulator but it can use real media (cartridges). You could probably build a system like that for the PCE.
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What about keeping the CD base for the main hardware, and using that little CD connector with a CD emulator that runs off SD card? Seems that little connector is mainly for passing data as read off the CD-ROM, and could be used with SD card with the hardware to handle it.
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I don't see why this wouldn't be doable and it's a great idea for sure. You'd just need to built a connector for the port at the back of the system that wires into a fpga which simulates the cd unit. For something like a turboduo you'd need to solder in a connector of some sort.
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The expansion connector and HuCard slot have many of the same signals/pins. You can do or imagine any method you want for playing CD images off a SD card or other media. Trying to hardware emulate/simulate the actual CD drive may be unnecessary. I think my idea is better if it will work. That is based on the CD games all properly using the BIOS for any interaction with the CD-ROM. If they do you could probably load off of any media you could imagine, though audio would require the media be fast enough for streaming it, or you could I guess just have something setup to cue a separate CD player.
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an sd adapter exists for the dreamcast to loads iso's. i'm sure its possible, and by all means give it a go. for me, i could only imagine using such a thing on a portable. gates of thunder on my gt would initiate the launch sequence. for the full size system their is something about having a cd drive, and would prefer it.
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an sd adapter exists for the dreamcast to loads iso's. i'm sure its possible, and by all means give it a go. for me, i could only imagine using such a thing on a portable. gates of thunder on my gt would initiate the launch sequence. for the full size system their is something about having a cd drive, and would prefer it.
Also for Gamecube and Wii. It bypasses the laser and spindle motor and feeds data from SD card into system.
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The problem i see with de pce cdrom is the red book
audio stuff. How do you gonna control this over the hu slot
or extension port? Since game data/psg sound is very independent
handled to the red book audio.
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The PCE doesn't use a 6502 though. Honestly if you have enough money, and it would be a lot, there is nothing stopping you from paying a company/lab to do the work to break it down and make it possible to clone it exactly. I want to see a DUO with SGX support and native S-Video & RGB output as well as Region Switching. That would be nice. But I don't know that we will ever see that. Something more likely is like those FireCore Genesis clones. Essentially it's a device that is just built to run an emulator but it can use real media (cartridges). You could probably build a system like that for the PCE.
Those don't emulate, at least not in the traditional sense. They're clone hardware. They use a GOAC, Genesis On A Chip, which is engineered to perform the functions of the Genesis at a level that is "good enough". They do probably have a pretty legit MC 68k knock-off core. It's the other functions that are usually a bit off due to them replicating things cheaply and in poor detail.
As for the PCE, the PCE CPU is a modified 65C02. There are schematics and markup files for the 6502 and, I believe, the 65C02. If you use those as a base you have a good portion of the core of the PCE's CPU already.
Here's some of the goodness I've already found...
http://www.visual6502.org/
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either way, playing iso's on a portable would be amazing, but i think its a pipe dream. it would be much cheaper to buy a cd unit that is working, or one that needs to be fixed and have our onsite experts fix it up.
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The problem i see with de pce cdrom is the red book
audio stuff. How do you gonna control this over the hu slot
or extension port? Since game data/psg sound is very independent
handled to the red book audio.
You can't do it with just the HuCard slot, atleast not in stereo. Instead you'll need to mix the audio from the proposed device playing the audiotracks with the system's audio output. It's not a huge deal. If such a device interfaced with the expansion port it would be no problem but would leave DUO's out in the cold.
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Well considering that then you won't need a duo... and a HuCard only PCE is way cheaper....
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While that's true then you need to get a Expansion Connector, and I'm not sure if you can find those easily. Also if you don't make whatever it is coexisting with the CD system, you'll have to clone the hardware for the extra sound channel. But it might not be a very complex setup to handle. Either way it would be a sweet project.
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i can make an expansion connector, its not to hard. sourcing one is a whole different story. Here is a picture of one i built. I sent the prototype to thesteve. its far more likely that he or guys like him could build them much faster and of higher quality.
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Is someone brewing something here ? :D
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not me, i'm not smart enough :) but i will help anyway i can.
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Has anyone ever done a complete disassembly of the Super System Card 3.0 BIOS? Or does anyone have a document detailing all the function calls in the BIOS? Since there are homebrew CD-ROM games I would guess someone has atleast some good information on the BIOS.
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don't think you need to. other members have stated you can use a flash card to load the bios on a portable system, or a system without a cd attached. Gameofyou's flashcard would be ideal for this.
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Did you post in the right thread? I have a feeling you might have intended to reply in a different thread. We were talking about ways to play CD-ROM games without an actual working CD-ROM drive. My suggestion is to tackle it from the BIOS rather than trying to emulate the hardware of the CD-ROM drive. It would work just find if all games follow procedure and use the BIOS to load data from CD-ROM and play Audio Tracks. Rewriting the BIOS functions to instead communicate with another storage device could be achieved. And the software approach would probably be easier and faster than attempting to clone the exact hardware behavior the CD-ROM has.
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So what you are suggesting is that to re-write the bios in a way that ISO games are loaded via the HuCard slot with a device similar in shape to Turbo Everdrive?
How would you go about re-writing the bios on the console?
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The problem i see with de pce cdrom is the red book
audio stuff. How do you gonna control this over the hu slot
or extension port? Since game data/psg sound is very independent
handled to the red book audio.
For proof of concept the nes powerpak reproduces entire audio chips found in famicom cartridges. The audio chips in the famicom carts only output a standard mono audio signal so if fpga can re-create that then I'm sure you could get something that can re-create red book audio.
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So what you are suggesting is that to re-write the bios in a way that ISO games are loaded via the HuCard slot with a device similar in shape to Turbo Everdrive?
How would you go about re-writing the bios on the console?
Yes, you just need a device to plug into either the HuCard Slot or Expansion Port to get all the connections you need. The BIOS should contain functions related to all disc operations. You can then hack these routines to use different hardware on this device to get the same data that would be stored on a CD-ROM normally and read by communicating with it. You are basically making the BIOS access a new storage device. It could be done if the BIOS is always used for such functions. The Famicom Disk System on the PowerPAK similarly uses a hacked BIOS I believe.
Again, mixing audio isn't a big deal, you could mix two signals together is inject the redbook audio. The whole task could be done.
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Did you post in the right thread? I have a feeling you might have intended to reply in a different thread. We were talking about ways to play CD-ROM games without an actual working CD-ROM drive. My suggestion is to tackle it from the BIOS rather than trying to emulate the hardware of the CD-ROM drive. It would work just find if all games follow procedure and use the BIOS to load data from CD-ROM and play Audio Tracks. Rewriting the BIOS functions to instead communicate with another storage device could be achieved. And the software approach would probably be easier and faster than attempting to clone the exact hardware behavior the CD-ROM has.
No Mott, i have no idea what thread i'm in, we were talking about skittles right. I don't have your understanding of the technical aspects, but i do grasp what your trying to do. I was only suggesting that if someone were to use an sdcard to load iso's (that was talked about in this thread right?) yet you would still need a cd capable bios to run said iso as its not emulation right? then using a flash card could cover the bios aspect of the problem. Otherwise i'm an idiot and was just trying to be part of the discussion :)
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Yes, you just need a device to plug into either the HuCard Slot or Expansion Port to get all the connections you need.
It would have to connect to the expansion port. Cards are missing the CD-detect signal :(
You don't have to re-write the bios, either. You just have to make the device -respond- like the NEC cd adapter.
Seriously: Make an IDE adapter for the expansion port. Then you can adapt whatever card you want to an IDE bus.
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If people can custom make pcbs with connectors for a hucard slot I'm sure you can make a custom connector for the pc engine expansion port.
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If you read my post on the previous page you will see i already have. its not perfect but it works.
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If you read my post on the previous page you will see i already have. its not perfect but it works.
Oh hey there we go proof of concept yet again.
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Did you post in the right thread? I have a feeling you might have intended to reply in a different thread. We were talking about ways to play CD-ROM games without an actual working CD-ROM drive. My suggestion is to tackle it from the BIOS rather than trying to emulate the hardware of the CD-ROM drive. It would work just find if all games follow procedure and use the BIOS to load data from CD-ROM and play Audio Tracks. Rewriting the BIOS functions to instead communicate with another storage device could be achieved. And the software approach would probably be easier and faster than attempting to clone the exact hardware behavior the CD-ROM has.
No Mott, i have no idea what thread i'm in, we were talking about skittles right. I don't have your understanding of the technical aspects, but i do grasp what your trying to do. I was only suggesting that if someone were to use an sdcard to load iso's (that was talked about in this thread right?) yet you would still need a cd capable bios to run said iso as its not emulation right? then using a flash card could cover the bios aspect of the problem. Otherwise i'm an idiot and was just trying to be part of the discussion :)
When I first read your reply it seemed like a reply to a similar topic elsewhere on this board. I think I was thinking of the thread about adding backup ram to a portable console.
The CD Detect signal isn't necessarily needed if you rewrite the BIOS. That signal may be more important to the actual CD-ROM drive, which if you rewrite the BIOS you can bypass that.
Either way, something could surely be done to emulate the CD-ROM to run ISO style images.
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its all good, i was being a bit of a wise ass anyhow, i figured you meant nothing by it.
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It's perfectly doable. The nes powerpak re-creates the entire famicom disk system on fpga connected through the cartridge connector. The famicom disk system loads data off of cheap disk media which is the same concept as a cd, and also contains custom audio hardware which the fpga recreates. The mega everdrive is a sega genesis fpga device which can play wav files so there's your redbook audio reproduction.
It's not a matter of "can it be done?" it's more a matter of "will anyone with enough skill ever get around to making this? And if so when?"
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The CD Detect signal isn't necessarily needed if you rewrite the BIOS. That signal may be more important to the actual CD-ROM drive, which if you rewrite the BIOS you can bypass that.
Okay, let's assume CD-Detect isn't needed.
Which bios are you going to re-write?
If 1.0, there go all the later games.
if 2.x, there goes altered beast (and a few others, iirc) and the super cd games.
if 3.x, no altered beast, but most everything else should play.
In any case, you're not going to get -all- the isos to play, unless you want to detect which program it is, and switch bios images. Good luck with that....
(I've never said it -can't- be done, though. It's just more trouble than doing an ide converter.)
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Rewriting the bios might be a mega pain. Even the fds fpga on the nes powerpak uses the regular fds bios dump.
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Doesn't Magic Engine already use a rewritten 3.0 BIOS?
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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.
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My understanding is that the Turbo / PCE CDROM is on the hardware level just a scsi drive. Surely an interface can be made.
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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?
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.
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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.
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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.
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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.
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well stop talking about it and do it. my gt need iso's to play
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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.
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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.)
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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?
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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
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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.
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...
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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.
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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.
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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.