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RickNel
May 24th, 2009, 11:14 PM
A lot of threads on MFM hard drives seems to end with people saying how crap they are and throwing them out.
In the spirit of this forum, I'm hoping to save one just for the heck of it.
It's an NEC-D3142, 42Mb. On power on, it spins up and seems to seek track 0. It came with an ISA-bus controller card from a Wang 80386 PC, but the card doesn't work in a standard PC ISA slot as far as I can determine in any AT mobo I have - possibly BIOS are all too new.
I have an S-100 system (IMS 5000) that I'm working on. The BIOS can be configured for MFM HDD.
If MFM drives have a reputation for failing, it stands to reason there should be some controller cards around that have no functioning disks to run on them.
Any ideas on where such s-100 MFM controller a card might be found (other than dumpsters)?
Did all MFM controllers have the same 34pin+20pin dual cable connections with the same pinouts?
Also, any source for documentation on the NEC-D3142. It seems to have been a pretty common drive in its time?
Any help or advice appreciated

patscc
May 25th, 2009, 12:11 AM
Well, first here's the man page for the drive:
http://support.necam.com/oem/HDD/D3142.asp

MFM gets a bit of a bad rep by folks coming of IDE & ATA spec stuff, which is pretty much plug and play. MFM drive types were often closely bound to the controller cards.
If you change your mind back to ISA, there's probably a controller out there.

Probably not the earliest ones, but If you can dig up a Cromemco STDC card. that should work with your drive.

patscc

MikeS
May 25th, 2009, 01:10 AM
Did someone say Cromemco? Yes, I do have one or two STDC's but not cheap...

Now if you wanted a WDI or WDI-II then we could definitely talk, but although they're MFM they're probably not what you're looking for. In answer to your other question, although MFM is commonly used to describe a hard disk using the ST412/506 34&20 pin interface, technically it only refers to the recording method and not the computer interface.

The IMI interface that the WDI's use is an example; the later 5 1/4" IMI drives could be bought either way, the same HDA and analogue board with either an IMI (single 34-pin cable) or ST506 interface board, for use with either a WDI or STDC respectively. As a matter of fact an upgrade kit was available consisting of an ST-506 interface board and the matching STDC controller.

RickNel
May 25th, 2009, 11:41 PM
to patssc - thanks for the specs link and other info

to MikeS - In this case, how does "not cheap" translate into $$?
I haven't seen anything pop up on ebay in the few weeks since I've been interested.

QuantumII
May 26th, 2009, 12:21 AM
I gutted a large CPM system yesterday, and inside I found a 8" floppy drive and a MFM HDD connected to a daugtherboard which in turn connected to a standard 8" floppy drive port on the controller.

I wonder what it's for ? Maybe it uses the HDD to create logical drives or something?

MikeS
May 26th, 2009, 11:14 AM
to patssc - thanks for the specs link and other info

to MikeS - In this case, how does "not cheap" translate into $$?
I haven't seen anything pop up on ebay in the few weeks since I've been interested.
Yeah, S-100 HD controllers are pretty thin on the ground; I wonder how hard it would be to make an S-100<>ISA bridge board... Andrew, are you reading this? ;-)

I'd say around $150 for an STDC, but frankly, unless you need one for a Cromemco I wouldn't recommend it. It's a fairly intelligent controller with a Z80 coprocessor, DMA controller, 64K RAM, 8K ROM etc. that reads and buffers an entire track at a time, so I'd think a driver or BIOS would be a bit of a challenge even if you did want to pay my exorbitant price... ;-)

m

Chuck(G)
May 26th, 2009, 11:44 AM
Outside of the Compupro Disk 3, I don't think I've ever run across an S100 ST506-interface controller. Even the Disk3 is very late in S100 history (~1984).

What's more common are SASI interface boards for S100 (little more than a parallel port) that connect to something like an outboard WD1001 controller hooking up to an 8" SA1000-type drive.

MikeS
May 26th, 2009, 12:05 PM
Outside of the Compupro Disk 3, I don't think I've ever run across an S100 ST506-interface controller. Even the Disk3 is very late in S100 history (~1984).

What's more common are SASI interface boards for S100 (little more than a parallel port) that connect to something like an outboard WD1001 controller hooking up to an 8" SA1000-type drive.
Well, Vector Graphic had at least one, basically a floppy controller with a few extra bits added to connect to a "real" ST-506.

Guess we've come full circle with IDE putting most of the smarts back onto the drive ;-)

QuantumII
May 26th, 2009, 12:06 PM
Here's that card I mentioned... Seems to be MFM-to-SASI (Shugart) controller

Xebec controller (http://www.swtpc.com/mholley/SASI/XEBEC.htm)

MikeS
May 26th, 2009, 12:08 PM
I can take a picture of the weird 8"-floppy-connector-to-MFM card.

Will post it here shortly.
Sounds intriguing all right; what's the make & model of the CP/M box and the drive?

QuantumII
May 26th, 2009, 12:20 PM
Sounds intriguing all right; what's the make & model of the CP/M box and the drive?

It was in a Tandberg TDV 2324 (Norwegian brand) CPM machine. I rescued the MFM HDD; the controller and the 8" floppy drive.

The HDD is a Rodime Series 200 , and the floppy drive is a Shugart.

Chuck(G)
May 26th, 2009, 02:08 PM
Here's that card I mentioned... Seems to be MFM-to-SASI (Shugart) controller

Xebec controller (http://www.swtpc.com/mholley/SASI/XEBEC.htm)

Yup, just like the WD1000/1001--insanely easy to imterface to. The WD controllers used the Signetics 8x300-series bipolar controllers. You can probably still find the WD controllers within the TRS-80 community.

My first IBM 5150 hard disk was a Shugart SA1004 and a WD1001, hooked to a homemade interface card in the PC.

MikeS
May 26th, 2009, 03:02 PM
Ah yes; I've got the SCSI version of the Xebec MFM bridge. Never figured out what to do with it though.

Chuck(G)
May 26th, 2009, 04:11 PM
Ah yes; I've got the SCSI version of the Xebec MFM bridge. Never figured out what to do with it though.

I've got a couple of OMTI RLL-to-SCSI cards somewhere. They're identified as having the "Mac SCSI" ROMs. At one time, MFM/RLL drives were cheap in comparison to SCSI drives. I think this sort of bridge card was useful as a money-saver. I used mine (wtih some external "glue" logic) to interface an Atari ST to an MFM hard drive.

Well, there's your "S100 MFM controller". SCSI isn't much more than a couple of parallel ports and software following a protocol definition, so it should be pretty straightforward to interface one of the SCSI-MFM bridge boards to an S100 parallel card.

RickNel
May 26th, 2009, 05:27 PM
My IMS International system docs (1981) refer to an optional "hard disk sub-system" with removable cartridges in optional capacities of 32mB, 64mB and 96mB, in each case presented to CP/M as multiple "diskette drives" of 8mB capacity. No hardware or vendor standard is mentioned, but maybe that configuration suggests a Shugart-style controller (SASI)?

Does anyone have information/memories on that style of HDD sub-system?

The IMS system's FDC is Shugart-compatible card driving two Tandon 5.25 FDDs.

The FDC card does not have any connectors or headers other than the two 34pin FDD connectors, so I guess the HDD subsystem was driven from its own s-100 card, not from a daughter-board like the interesting XEBEC shown by MikeS.

So some kind of s-100 card must have been out there from around 1980 to as long as these machines were still running.

My puzzle is still - how to connect a NEC D3142 to a S-100 system.

Chuck(G)
May 26th, 2009, 05:57 PM
Your IMSI hard controller sounds like an SMD interface, not ST506 or SASI. Just a guess, however.

QuantumII
May 26th, 2009, 10:48 PM
Yesterday I got the cover off my TeleVideo machine, and inside it had a similar adapter for connecting the HDD. Floppy connector (A flat one, you plug the floppy-end of the cable into it) in one end, and MFM hdd connectors in the other end.

Maybe they're quite common after all..

The TeleVideo is a multi-user Z-80 machine, but not S-100

QuantumII
May 27th, 2009, 03:26 PM
Hey, an update on the MFM S-100 controller.

I have here the Cromemco STDC, which is a S-100 bus ST-506 controller :-)

This is exactly what you are looking for right ?

The link to the manual is here (http://www.classiccmp.org/dunfield/s100c/crom/stdc.pdf)

It was in a pile of other misc cards I got from my haul.

Chuck(G)
May 27th, 2009, 04:08 PM
Looks like it. I note that the documentation mentions no other OS except Cromix. Do you have any driver software for it?

RickNel
May 27th, 2009, 06:23 PM
The control and data cable connectors match the NEC D3142, but its hard to see how this card could run between CP/M and the NEC HDD. Unless Cromemco had a CP/M implementation for it with a different manual.

Even so, that Interrupt Priority Cable looks scary - is that a feature of Cromix-based systems or Cromemco generally? Not compatible with my system as far as I can see... Interrupts are all handled through the bus and system I/O card. This manual seems customized for a particular HDD with no other options.

Would there be workarounds?

Chuck(G)
May 27th, 2009, 07:17 PM
Reading the STDC manual, it's an interesting beast.

What sticks out first is that no sectoring is done on the hard disk--each track is handled as a single long sector of about 10K. The board has 64K of memory and the docs say that there are 4 read/write buffers and 1 verify buffer (that would amount to 50K of the 64K). Can you say "blocking and deblocking code"?

It's not clear if you can access the buffers using programmed I/O or if DMA is required. If the latter, I can see problems ahead. DMA was one of those things that was extremely variable between vendors. It might be possible to get the board to work without interrupts, however.

Like a lot of Cromemco stuff (particularly the later stuff) is somewhat scarce on programming information and this board is no exception. It was made to run with Cromix (no mention of CP/M is given).

Maybe Herb Johnson at Retrotechnology has programming information. Otherwise, if you're set on using the board, you'll have to do your own reverse engineering.

MikeS
May 27th, 2009, 09:53 PM
Yeah, that's what I was saying earlier: it's not your average ST506 controller, but a 64K Z80 computer with 8K of ROM and a number of undocumented PROMs. AFAIK not even the latest versions of CDOS (Cromemco's version of CP/M) could talk to it, only 68K Cromix and the last few versions of Z80 Cromix, and other than the sparse manual and system-level calls I've also never seen any detailed technical info. The interrupt priority jumper would be the least of your challenges.

Like I said, unless you have a Cromix system I'd think that it'd be a major challenge to use an STDC in a CP/M system. There is a test/exerciser program for the STDC/ST506 HD; I suppose if you could rig up something to snoop the bus while issuing commands you might learn something useful, but I think one of those SASI<>MFM bridge boards would be a lot easier, while a Cromemco owner might be able to appreciate the STDC much more.

The STDC and DPU are relatively rare, so if Quantum can find an FDC and memory card to go with them he's got the makings of a pretty good Cromemco system.

Chuck(G)
May 27th, 2009, 10:47 PM
With a schematic and the PROM, it could certainly be reverse-engineered. The problem is that it might as well be a one-of-a-kind deal that's going to take a lot of work to get going. I don't much care for the "sector-is-a-track" approach either.

I'd sooner use a generic parallel I/O interface to talk to a SCSI or IDE hard drive.

QuantumII
May 27th, 2009, 11:51 PM
The STDC and DPU are relatively rare, so if Quantum can find an FDC and memory card to go with them he's got the makings of a pretty good Cromemco system.

I found both on ePay, but very expensive.. I will have to look for more cromemco boards the next time I take a trip to the place I got them.

I think this controller will be placed in a parts box, and I'll focus on getting my CCS S-100 machine do something more than spin a fan and light up a led.

Chuck(G)
May 28th, 2009, 11:00 AM
I'd recommend that you get the Xebec hard/floppy (if that's what it is) controller going. It should be a fairly easy job as most of the "smarts" are on the board, not on any S100 card.

QuantumII
May 28th, 2009, 11:56 AM
Yes, if I ever get the S-100 system running I could try to get it running.

See my thread CCS S-100 Woes (http://www.vintage-computer.com/vcforum/showthread.php?t=15802) on what I'm struggling with at the moment.

RickNel
June 10th, 2009, 04:42 AM
Reverting to my original topic...

MikeS suggested crafting up an interface to a parallel IO card.

I notice that Howard Harte has contributed open source code for an ST506 controller for the SIMH AltairZ80 emulator environment.

http://simh.sourcearchive.com/documentation/3.8.1/s100__disk3_8c-source.html.

This would be a useful start for anyone looking to build an ST506 software driver, highly configurable, maybe without the need for a separate controller card. Just speculating.

I'm guessing there would be I\O speed limitations, but is there any other factor that would make that approach unworkable?

Rick

Chuck(G)
June 10th, 2009, 09:37 AM
I don't follow (I'm probably very thick today)--the SimH driver given is for a CompuPro Disk3 card. Do you have one of those or a CP/M configured to run with that and the cards on your CCS? :confused:

RickNel
June 11th, 2009, 04:19 PM
Chuck - you are not thick but I am new to a lot of this, so forgive me if I have to start by asking dumb questions.

Quantum has the CCS - I started this thread in relation to my IMS which has similar configuration, but NO s-100 MFM controller card, just an ISA bus ST506 controller from a dead Wang PC.

To clarify - my last post was asking whether it could be possible to craft a driver that would directly address an ST506 drive (eg my NEC D3142) connected via the parallel port on a S-100 system.

MikeS suggested the port could be used that way, in context of a bridging card. If I wanted a season in Hell, I could think about trying to bridge my ISA controller to the S-100 bus.

I'm not suggesting the SIMH Disk3 driver would do the job as is, just that the code might provide at least part of what is needed to make a purely software interface. I understand that the SIMH Disk3 emulator emulates the whole drive system, not just a driver for a real Disk3 card. Do I have that wrong?

What I don't know is whether the controller cards do anything that could not be emulated in software using RAM and a typical S-100 I\O card. In the end, the ST506 interface is two data pins and a bunch of control pins. Is it possible that the buffering and control register handling that is typically done on a controller card could be set up in system RAM and directed through the parallel port?

If the answer is straight NO, I'll keep looking at other solutions, but this thread suggests there are no easy answers.

Rick

billdeg
June 11th, 2009, 04:47 PM
I think yes this is possible. I have an S-100 system with a non S-100 hard drive controller myself. It depends on the card, but you may have to add/remove things like voltage regulators, etc. It'd be a project.

Here is a link I refer to time with some good info on ST506 interfacing. Kelly L sent it to me in early 2006. It does not directly apply to your project, but it may help.

http://nemesis.lonestar.org/computers/tandy/hardware/storage/mfm.html

Chuck(G)
June 11th, 2009, 05:36 PM
To clarify - my last post was asking whether it could be possible to craft a driver that would directly address an ST506 drive (eg my NEC D3142) connected via the parallel port on a S-100 system.

MikeS suggested the port could be used that way, in context of a bridging card. If I wanted a season in Hell, I could think about trying to bridge my ISA controller to the S-100 bus

Actually, it wouldn't be that bad. One of the tricks that has long been used by the microcontroller hobbyists is using an ISA NIC connected to a microcontroller such as an ATMega128.

You'd want to use a 16-bit (AT Style) MFM controller as those generally don't use DMA for data transfers (which would be a bother). All of the control and status registers in an AT controller are 8 bit; only the data path is 16 bit. If you didn't mind tossing half of each 512-byte sector out the window, it'd be pretty simple. It'd actually be harder to interface to the floppy part of a MFM HD-floppy controller.

Heck, if someone can make a USB-to-ISA adapter, S100-to-ISA should be easy.

RickNel
June 13th, 2009, 04:28 PM
OK - thanks. You've given me a reason to look harder for documentation on the Wang ISA controller (ISA on 386 AT-like motherboard but not PC-compatible - zero documentation so far).

The sector size issue - perhaps could be handled by buffering in RAM, the way CP/M systems commonly buffer 2 x 128b CP/M records for read-write to 256b FDD sectors?

I still haven't been told that an all-software solution is not possible as well.

Not rushing at this... it's waited 20yrs so far so can wait a while longer.

Chuck(G)
June 13th, 2009, 04:50 PM
I still haven't been told that an all-software solution is not possible as well..

Well, no, for an MFM drive, you have to be able to service a raw bitstream at 5MHz , which is way faster than any of the "vintage" machines will go. And that raw bitstream uses differential signaling.

On the other hand, interfacing an IDE drive to a pair of parallel ports might well be possible on an S100 system without much other than some cabling and a suitable power supply for the drive.

RickNel
June 13th, 2009, 11:43 PM
Right - that settles it then, those bitstream specs mean there's no hope of avoiding a hardware controller on a system chugging along on 4MHz CPU!

Looking at the Wang controller board , I see a WD11C00C-JU controller chip (same as used on IBM AT-5150 I believe), and three crystals at 16MHz, 10MHz and 9.6MHz.

Google hasn't heard of this controller card: HFA-100.W2 P/N 96-0000-1080-2. Any suggestions on suitable docs repository? Docs for a similar card for IBM AT-5150 might help somewhat.

Chuck(G)
June 14th, 2009, 09:39 AM
Google hasn't heard of this controller card: HFA-100.W2 P/N 96-0000-1080-2. Any suggestions on suitable docs repository? Docs for a similar card for IBM AT-5150 might help somewhat.

A photo might help--often these things followed a generic design.

Marty
July 26th, 2009, 01:02 PM
Hi all;
I have an s-100 hdc controller that was built especially for miniscribe, I have No information it, it has plenty of extra ic's more than the average controller for a hard disk controller.
Thank YOu Marty

gv308
August 4th, 2009, 03:26 PM
DTC made S100 SASI adapters, I used them to interface to Xebec 1410's. I still have the DTC manuals and BIOS and utilities source code, don't think I have the SASI S100 schematic though. However, SASI is quite simple, a subset of SCSI.

This link seems to be a good starting point? Lists many controllers, and even art work for a host adapter.

Gerrit

fibrewire
March 14th, 2011, 10:49 PM
Old thread. Got it. :)

i just got a s-100 disk controller for a Corvus Systems hard drive. Photos are here (http://www.atariage.com/forums/topic/144804-corvus/page__st__25)
I'm looking for a serial to MFM controller. Anyone know of such a device? I figured a serial connection would be the most universal, and wouldn't limit to just one retro system.

MikeS
March 15th, 2011, 12:00 AM
Old thread. Got it. :)

i just got a s-100 disk controller for a Corvus Systems hard drive. Photos are here (http://www.atariage.com/forums/topic/144804-corvus/page__st__25)
I'm looking for a serial to MFM controller. Anyone know of such a device? I figured a serial connection would be the most universal, and wouldn't limit to just one retro system.Not sure what you're asking here; you ask what that controller's for? Not to be a smart ass, but presumably to interface a Corvus hard disk to an S-100 system like the Zenith that you mention...

As to the "serial" connection, far from being "universal" I can't think of *any* retro system off-hand that could use a serially-connected MFM drive without some serious driver writing except perhaps the Corvus drives, but they're hardly any "standard" serial interface...

fibrewire
March 15th, 2011, 01:16 AM
I typed out a lengthy explanation, but accidentally clicked the back button on my Microsoft Natural Wireless Laser Mouse 7000. Probably the better half of 30 minutes was spent creating my reply. I will answer your question shortly, as i need to take a brisk walk to the coffee machine. :)

MikeS
March 15th, 2011, 08:35 AM
I typed out a lengthy explanation, but accidentally clicked the back button on my Microsoft Natural Wireless Laser Mouse 7000. Probably the better half of 30 minutes was spent creating my reply. I will answer your question shortly, as i need to take a brisk walk to the coffee machine. :)Been there, done that, T-shirt hanging in the closet, and feel your pain; hope there's something in your bottom desk drawer to fortify the coffee a bit ;-)

Chuck(G)
March 15th, 2011, 10:55 AM
Is there a shortage of MFM controllers for the ISA bus? Since most of the (16-bit) ones, use PIO for data transfer (not DMA), might it not be more interesting to simply make an S-100-to-ISA adapter? You then get the entire range of ISA peripherals at your fingertips. Just write the drivers...

fibrewire
March 15th, 2011, 03:05 PM
I am exploring a ST-506 to some standard interface. Then from the standard interface to your choice of retro computer interface.

Apparently the MFM to SASI interface already exists. This whole idea spawned from having a Corvus Systems hard disk with no interface to any computer. I just purchased a S-100 corvus interface, but I am waiting to see if it's works. I would really like a Corvus SYstems hard disk to Atari interface, but that seemed next to impossible. A guy from AtariAge said he could help, so I am gonna wait for now. What would really be cool is a SASI to USB interface. Then we could access all the rare data stored all over ebay. Hell, I would have a field day buying old drives on the cheap and seeing whats on them.

There are easier solutions i'm sure, but learning how ST-506 works would be a cool way to cut my teeth on electronics design.

fibrewire
March 15th, 2011, 06:02 PM
MikeS: You had mentioned that SASI is little more than a parallel port. Is there any information you can point the way to how SASI works? I would really like to see a SASI to Atari SIO or SASI to S-100.

NobodyIsHere
March 16th, 2011, 03:58 AM
Hi! I'd be willing to help make a PCB for a S-100 to ISA board assuming someone can send me a schematic. I believe this would be a lot more than just connecting the address and data busses. There would need to be some kind of signal translation for the control signals between the S-100 and ISA busses.

I am pretty swamped at the moment with other S-100 and ECB related projects so this would have to be a community effort along the lines of the boards John Monahan and I have made. The group approach has worked well for our boards, the S-100 68K CPU board, and a variety of other projects. Also working with Rich on a S-100 6502 CPU board.

Thanks and have a nice day!

Andrew Lynch

monahan_z
March 16th, 2011, 09:03 AM
Andrew I made an S-100 to ISA adaptor 30 years ago (still have it here) and did a write-up about it for Sol Lib's Microsystems Journal at the time. You could use it for example with the old IBM VGA adaptor. Needless to say with the current set of S-100 boards we have in the works (new IDE, 8086, Console I/O, and 68K boards) it would be some time until we could get to it.

MikeS
March 16th, 2011, 10:17 AM
MikeS: You had mentioned that SASI is little more than a parallel port. Is there any information you can point the way to how SASI works? I would really like to see a SASI to Atari SIO or SASI to S-100.Actually it was Chuck who said that...

I'm really confused about just what it is that you want to do; IMHO the best thing to do with the Corvus (IMI) disk (and maybe the S100 card as well) is to sell it to someone whose system needs it.

And how will a SASI to USB interface let you "access all the rare data stored all over ebay"? What did you have in mind?

Also, direction matters; there are certainly SASI/SCSI-to-MFM bridge boards out there (I've got one or two somewhere) but AFAIK there are no MFM-to-SASI (or anything for that matter) converters (assuming of course that when we say MFM we're all really talking about the ST406/512 interface).

Chuck(G)
March 16th, 2011, 12:31 PM
I should add that what I said in context was that the SASI ]u]interface[/u] is little more than a parallel port. What goes between an MFM drive and the SASI interface (i.e. the controller) is a whole 'nother matter... :)

Sort of like saying that IDE/PATA is little more than a naked ISA bus. True, but there's a lot of logic onboard an IDE drive to get to that interface.

MikeS
March 17th, 2011, 12:21 PM
I should add that what I said in context was that the SASI ]u]interface[/u] is little more than a parallel port. What goes between an MFM drive and the SASI interface (i.e. the controller) is a whole 'nother matter... :)

Sort of like saying that IDE/PATA is little more than a naked ISA bus. True, but there's a lot of logic onboard an IDE drive to get to that interface.Yeah, there seems to be some confusion about drive interfaces vs. computer interfaces and also the physical vs. the logical aspect of the interfaces...

I wonder if there's a table somewhere listing all the possible combinations, or at least those that actually existed; was there ever an ISA bus controller for a Corvus drive, for example?

Chuck(G)
March 17th, 2011, 02:22 PM
Well, I have an Ampex Megastore card here that's SASI and I know that there were ISA SMD adapters. Then there are the converters (MFM-to-SCSi?SASI)...

Which is curious because I'd guess that SMD would have been the logical choice for the S100 community in the early days of S100 systems. Few (other than hard-bitten minicomputer fanatics) in the vintage community are even familiar with SMD.

MikeS
March 17th, 2011, 02:37 PM
Well, I have an Ampex Megastore card here that's SASI and I know that there were ISA SMD adapters. Then there are the converters (MFM-to-SCSi?SASI)...

Which is curious because I'd guess that SMD would have been the logical choice for the S100 community in the early days of S100 systems.Well, as I recall from those days SMD drives were more expensive than the IMI/Corvus drives et al that preceded the (relatively) cheap ST-406s.

But now You're confusing me (easily done): I thought that you usually name these things from the computer point of view? There were certainly converters that took SASI/SCSI from the computer to an ST-506 drive, but not the other way (MFM controller to a SASI/SCSI drive) or this discussion would be largely moot. Is there a convention, i.e "SCSI to MFM" or "MFM to SCSI" when the drive is MFM?

Chuck(G)
March 17th, 2011, 03:33 PM
Not that I'm aware of. Sort of like the AT-to-XT keyboard converter discussions. I'm never quite sure which is meant.

But SMD precedes ST-506 by a fair number of years. In 1975, it probably would have been the only common hard disk interface available to a S100 user. SASI didn't come along until 1979. The SA-4000 14" Winchester was 1978. WD made both support devices (WD1050) and board-level products WD1002-MFT for SMD drives.

fibrewire
March 19th, 2011, 02:07 AM
I found what I was looking for, now i just need to buy one. A ttl board that makes a select few ST-506/ST-412 drives into SCSI drives.
538353845382
5381

Also ***FREE*** Corvus Systems S-100 board. For whoever needs it. (http://www.atariage.com/forums/topic/179037-corvus-systems-s-100/)

Chuck(G)
March 19th, 2011, 10:56 AM
Good luck with that--you may find that (like the OMTI) the version of "SCSI" is significantly downlevel from what most SCSI controllers will accept.

MikeS
March 19th, 2011, 11:29 AM
I found what I was looking for, now i just need to buy one. A ttl board that makes a select few ST-506/ST-412 drives into SCSI drives.
538353845382
5381

Also ***FREE*** Corvus Systems S-100 board. For whoever needs it. (http://www.atariage.com/forums/topic/179037-corvus-systems-s-100/)I could maybe use that since I have a few Corvus drives and S100 systems...

Glad you found what you're looking for; out of all the different things you mentioned (serial<>MFM, Corvus<>Atari, SASI<>USB, SASI<>Atari, SASI<>S100), SASI or SCSI<>MFM was about the only one that you didn't mention ;-)

When you're hunting, aside from that BMS-100 and the OMTI that Chuck mentions, keep an eye out for Xebec; they also made SASI and SCSI to MFM bridge boards.

Good luck!