• Please review our updated Terms and Rules here

Another round of SCSI to IDE/CF/SD prototype boards?

Another round of SCSI to IDE/CF/SD prototype boards?

  • Yes, at $20 each prototype PCB for my own build and test

    Votes: 10 83.3%

  • Yes, at $20 each for someone else's build and test

    Votes: 2 16.7%
  • Total voters
    12
N

NobodyIsHere

Veteran Member
Joined
Dec 21, 2006
Messages
2,410
Hi! This is assess the level of interest in another round of SCSI to IDE/CF/SD prototype boards. I can get another batch and I've already had some requests. Please respond to the poll if you are interested. At least notionally, if I get 10 of the PCBs they would be $20 each to cover my costs.

This is a home brew community project so each builder constructs their own board. The SCSI to IDE/CF/SD project is currently underway with at least a couple builders with partially constructed units. No fully operational systems yet though as of 12 Jul 2011 AFAIK. As progress continues software and images will be posted to the N8VEM wiki.

Development of the software continues in an informal private email group with occasional updates to the N8VEM mailing list. All the design information is stored here on the N8VEM wiki

http://n8vem-sbc.pbworks.com/w/browse#view=ViewFolder&param=MINI SCSI to IDE prototypes

Thanks and have a nice day!

Andrew Lynch
 
Last edited:
Hi! Yes, that is the purpose of the SCSI to IDE/CF/SD community project. It's goal is to make available a low cost, reliable, home brew solution for early microcomputers which rely on SCSI-1 hard drives. As you no doubt are aware, SCSI-1 drives are becoming increasingly rare items while IDE drives, CF, and SD are still relatively plentiful.

The SCSI to IDE/CF/SD design is simple "bridge board" similar to other devices of the same vintage. There is nothing fancy about it and uses common generic parts with easy construction (DIP/PLCC PTH) dual layer board. As a result, this will be relatively easy to build and modify but it will never be a high performance unit. Probably will be decent enough for early microcomputers like Amiga, Mac, Atari, etc. I am expecting XT-IDE like performance more or less.

Interestingly enough, there have been several inquiries from users of non-microcomputer SCSI-1 devices like test/lab equipment, synthesizers, sewing machines (?), and other miscellaneous items. I have no earthly idea if this board would be suitable for them or not. All I can suggest is that if they are interested in application of the board outside the intended target machines is to try it. No assurances as to whether it will work though.

What the project needs most is some software development. There appears to be a couple of builders trying to get at least some level of software working. I haven't seen any images or boot screen photos yet although they should be coming. I have no idea when though. Much of the software is basic reuse of existing N8VEM projects and I expect a large majority of the code will be recycled SBC V2, PPIDE, and Juha SD ROM images. The SCSI interface software is probably where the majority of the actual work needs to be done.

Personally I don't have any machines that use SCSI-1 and limited use of the board itself. However the community project aspect of it is interesting somewhat like the XT-IDE project.

Thanks and have a nice day!

Andrew Lynch
 
This would be an even more useful project if there was a 2.5" SCSI -> CF/SD adapter created. I have several machines (old Apple PowerBooks, DEC Multia, etc.) that rely on these drives, and they were never plentiful, even when new. Now they're unobtanium, and, when found, are completely unreliable.

There is a guy on the 68k MLA forums trying to design one, with not a lot of success.

Thanks!
- Alex
 
Hi, take a look at the schematic and PCB layout... it includes a "laptop SCSI" interface for the 2.5" SCSI drives and the "regular" SCSI-1 for 3.5" drives. In theory, this should work with IDE/CF or the SD straight to the SCSI connector. Whether the PCB fits in the form factor is another issue though since this is the classic Eurocard 6.5"x4" (160x100mm) PCB.

Thanks and have a nice day!

Andrew Lynch
 
I wish I knew how to do the software side. I'm barely any good at soldering, although I did successfully put together an XT-IDE board. I'm really excited to see this come to fruition though!
 
Ditto. I've stated my stance on the project in the other thread, but I'm really hoping that this comes to fruition. I just don't have the SCSI experience to properly test, nor the software experience to help on that end.

For me, it would be nice to be able to use this on the Atari ST and big-box Amiga systems.
 
Unfortunately, the maximum size for a 2.5" disk is 69.85 mm (width) × 100 mm (length) x 19 mm (height). That's what I was hoping for.

Any chance that a simple removal of the CF/IDE support and re-route would get the board to an appropriate size? I know that's still a significant amount of work, for a limited market.

Thanks!
- Alex
 
Huh, I bet this could be done with one of the larger 16- or 32-bit PICs and a SD card. The larger devices have multiple master/slave parallel ports. I was thinking of doing a similar thing on a wedge board to give mass storage to Z80 computers like the Kaypro. The hardware would be pretty small, too.

You could probably shrink the board considerably and keep the same basic design by switching to SMD or PLCC parts entirely. I know the Z80 is available in PLCC and QFP form, as is the 8255 PIA.
 
ajacocks said:
Unfortunately, the maximum size for a 2.5" disk is 69.85 mm (width) × 100 mm (length) x 19 mm (height). That's what I was hoping for.

Any chance that a simple removal of the CF/IDE support and re-route would get the board to an appropriate size? I know that's still a significant amount of work, for a limited market.

Thanks!
- Alex
Click to expand...

Hi, at this point we still need to get the basic design and software hammered out. I'd like this to be as general purpose as possible to support IDE (mostly CF) and SD at once. I don't see a redesign of the hardware as practical until at least the next generation of boards. The good news is I think we are getting close to a working first generation board.

Thanks and have a nice day!

Andrew Lynch
 
glitch said:
Huh, I bet this could be done with one of the larger 16- or 32-bit PICs and a SD card. The larger devices have multiple master/slave parallel ports. I was thinking of doing a similar thing on a wedge board to give mass storage to Z80 computers like the Kaypro. The hardware would be pretty small, too.

You could probably shrink the board considerably and keep the same basic design by switching to SMD or PLCC parts entirely. I know the Z80 is available in PLCC and QFP form, as is the 8255 PIA.
Click to expand...

Hi Glitch,

Yes, this was the subject of much debate on CCTALK list too. Nothing came of it but many people insisted that it could (even should) be done with a uC. I don't doubt it could be done but in the end no one did anything.

I went with the Z80 DIP/PLCC/PTH design since it is easily constructed by amateur hobbyists compared to using SMT design even though the latter would be much smaller. It's just a personal preference but I tend to design for easy construction and to be as inclusive as possible in the hobbyist designs. Also, with the exception of the Z53C80 chip, the rest are basically reuse of existing N8VEM designs.

Thanks and have a nice day!

Andrew Lynch
 
I understand about wanting to stick with through-hole or socketed PLCC components...it definitely increases the number of interested people, as many people are scared off by SMD projects. I've stuck to the same design with my 8085 SBC.

I do plan on actually doing something with the uC SD interface concept...I've been playing around with the 18F series PICs for a few projects, and this will likely be one of the adaptations when I get time. My solution would be SD-only, and right now I'm not intending on making it a block-type device: the PIC would basically allow something else to send 8-bit commands to it and get 8-bit data back from the SD card (though making it send blocks at a time or do DMA wouldn't be that far of a leap).

As long as you have room for the board, doing it with a Z80 is far classier anyway!
 
I would definitely be interested in one of these once there's some basic software available, though I would also likely grab two if I were going to get one, haha.

Not that I'm currently reliant on SCSI-1 for anything, but I like to keep well stocked in whatever sorts of assorted adapters that I can find, you never know what you'll be trying to get working someday.
 
I'm always hoping (though the hope may be slim) that I one day will lay my hands on a Norsk Data ND-5000 minicomputer with SCSI. The SCSI controllers available for them were SCSI-1, but the disks that they came with (usually Control Data (CDC) 630MB or 1.2MB disks - the former were better because they didn't hang on to the bus as long as the large ones) were very sensitive to their environment. In one particular site I regularly had to reformat the disks every 3 months and restore a full-volume backup.

So, if I could really find one of those computers again.. I would wish to use something else than the original disks with those controllers. And so I should in principle get a scsi-1to ide/cf/sd adapter (or would I need one for every disk?) just in case that ever happens.

-Tor
 
Tor said:
So, if I could really find one of those computers again.. I would wish to use something else than the original disks with those controllers. And so I should in principle get a scsi-1to ide/cf/sd adapter (or would I need one for every disk?) just in case that ever happens.
Click to expand...

Hi! I don't know the specifics of your computer but in general these bridge boards would be a one-for-one replacement for a SCSI-1 disk drive. It is *not* a SCSI controller since it would plug into the existing SCSI controller to appear as a drive itself. The bridge board's Z53C80 has to be used as a target rather than an initiator.

Thanks and have a nice day!

Andrew Lynch
 
lynchaj said:
Hi! I don't know the specifics of your computer but in general these bridge boards would be a one-for-one replacement for a SCSI-1 disk drive. It is *not* a SCSI controller since it would plug into the existing SCSI controller to appear as a drive itself. The bridge board's Z53C80 has to be used as a target rather than an initiator.
Click to expand...

The 53C80 is perfectly capable of being a host, as opposed to a target on SCSI. That was the part that was used in one form or another on every Macintosh up through
the 68040 machines. It's all a matter of writing host as opposed to target firmware.
 
I got my CF/IDE adapter all ready to go (mounted to a pcmcia slot cover), now It will sit and wait for this puppy to come out when ready!
 

Attachments

  • cfcard_adapter_complete.jpg
    cfcard_adapter_complete.jpg
    95.3 KB · Views: 1
Last edited:
YES YES.
I want 2 if a production run is done and they are compatible with my hp Apollo 9000/715 50
 
You must log in or register to reply here.
Back
Top