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TEAC 55-GS SCSI Floppy Drive Issues

bolex

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I've been trying to get a a TEAC FD-55GS working in DOS for several days now with no luck. I just can't get the SCSI card to recognize the device. I'm wondering if anyone has been able to successfully get one of these to work in DOS and if you had, what jumper settings and SCSI Card did you use?

I have pulled the floppy drive (a TEAC FD-55GFR 701-U) and tested it with a regular floppy controller and it works fine. I was able to format disks, read and write with no issue. Scandisks showed perfect disks. The disks were readable in other 1.2mb drives. It appears that the floppy drive is ok - at least with a PC floppy controller. The only physical issue I can see wrong with the drive is that the DS3 jumpers are broken off, but I don't see that as a problem.

I tried using the drive with a TEAC FC-1 card and it acts the same. The SCSI card does not recognize FC-1 SCSI bridge/controller. Based on my experience with the FC-1, this is typical behavior when your floppy drive is not compatible with the FC-1 or not correctly jumpered. This FC-1 tests and works fine with compatible 1.44MB drives, but does not work with the 1.2MB floppy drive.

Documentation is pretty thin. I did find this configuration section in some kind of industrial automation device made by Foxboro. I've spent hours trying various jumper settings. I think the only thing left to try are different SCSI cards. I'm currently using a Future Domain card, but I have an Adaptec 1542CP as well as a Trantor T160 on the way.

I guess the questions are:

What floppy drives are compatible with the TEAC-55GS. The Foxboro documentation lists FD-55GFR-141-U and FD-55GFR-701-U. Are there more compatible floppy drives than these 2?
Does the model even matter? Will any FD-55GFR work?
What Jumper settings on the 13332137-00F bridge/controller work?
What SCSI Cards are known to work?

I keep thinking that this particular model might have been made for a specific system and therefore will never work in DOS. The Foxboro documentation indicate that's a UNIX based system.

Any other suggestions or information would be much appreciated. Thanks!


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Chuck(G)

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The big difference between a 55GF and a 235HG is that the disk spins at 360 RPM in the 55GF and 300 in the 235HG. You could set the jumpers on the GF to run in "dual speed" mode, which would drop the low-density spin to 300 RPM, but stay in 360 RPM for high. That might work, but I'm not optimistic--and you'd be stuck with using the 5.25" low-density as a 720K drive (i.e. no 360K floppies). The high density mode of the 55FG is more akin to the 1.6MB mode of the FD05HGS, but notice on PDF page 50 what the assignment of the density pins are.
 

bolex

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I would be happy to get it working as a 720K drive just to see the device show up during startup. I've tried just about every jumper combination available. I just don't think the floppy is reporting a "Ready" state to the controller for some reason. I'm almost leaning to the idea that that part of the floppy is not working properly. Those pins U0, U1, U3 are not used in the PC world, but these SCSI floppy need those jumpers set and working to be configured correctly. I think I'm going to try to find another floppy drive and see.

The 55GS brochure says it will read all modes but will only write the 96TPI formats - which is interesting. I thought that this would be something the SCSI bridge would handle, but you might be right in that it's wholly dependent on how the floppy is configured.


Modes.JPG
 

bolex

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I, unfortunately, don't have a FD55B handy. I did try a Teac 55FV - which is a weird 96tpi 80 track drive. It behaved the same. In a few days I'll try different SCSI cards. I'm also going to try to find a FD-55GFR 141-U - which is mentioned in the in the documentation above. Based on a sold ebay listing, it appears that It has a few more jumpers than the drive I'm working with now. Maybe that will make the difference.
 

Chuck(G)

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I think bitsavers has a rundown on jumpers. I do know that the original ED (3.5" 2.88) FD235J drives packaged with the FC-1 have lots of jumpers. You could also play with sending SCSI CDBs directly to the controller. I've had to do that with a few old SCSI devices to figure out what's what.
 

bolex

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I found a source for two more of the FD-55GS drives. They'll be here next week sometime. I also have a local friend who has a 55GFR he's going to sell me.

I tried a Trantor SCSI card and it behaved exactly the same as the Future Domain one, so I'm really leaning toward a bad floppy drive. I guess I'll find out when I get the new drives in. I'll let you know how it goes next week.

On another note, I found an SMS OMTI SCSI Floppy Bridge. So it looks like I might have a few options to play around with.
 

Shadow Lord

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Not to be obtuse but is there a reason you need to uses a scsi fdd? I.e. is this a must have for an exotic system or is more of a hey wouldn't be cool kind of a thing?
 

bolex

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Haha! There is no reason whatsoever other than I want to figure it out. It's just the current rabbit hole I've gone down. Give it time, I'm sure I'll find something even more stupid to play with.
 

bolex

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I'm making a bit of progress. Unlike the FC-1 Controllers that get their power from the floppy drive, this original FC-1 in the 55GS needs a power source. I just rigged up some small clips to +5 & G and the SCSI card was able to see the floppy drive and the driver was able to load. I assume this is the correct power since that cap right there is a 10V 100uf, but truthfully who knows. I can't find any documentation. Drive is still not working (it does not seem to be seeking), but at least it's something I can troubleshoot.


Does anyone know where I can get a source for this female power connector?

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bolex

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I finally was able to get this drive working. It works amazingly well.

I don't think I've ever been so frustrated with getting something working before. There is just no documentation on how to use these drives. None. So it was a ton of hit and miss and there are so many jumper possibilities. Hopefully I can help someone avoid this in the future.

I did have to make a power cable for the FC-1 Controller. The connector was a JST-XH 2 pin connector. I have 2 other FC1 controller boards and neither of them needed their own power and somehow used power from the floppy cable. The 2 earliest FC-1 Controllers need external power it seems. This is just 5 volts from a standard power connector.


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I found someone that had an 55GS in stock and they sent me a picture and the jumper settings were different from what I had above from the Foxboro Manual. I tried them and they worked! The Foxboro manual is not correct for DOS and so these are the correct Jumper settings on the Floppy Drive that are working for me.

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These are the FC1 Jumper settings I'm using. On the FC-1 Controllers, the G, F, J jumpers signify the TEAC drive compatible modes and sizes of drives you want to use. So these jumpers mean that it is compatible with G and F type floppy drives (1.2MB and 720K - The 360K is a given). The newer FC-1's have a J jumper for 2.8MB drives. I could not get this to work with any other drive so I think that these early FC1s are only compatible with the Teac Model FD-55GFR-141-U and FD-44GFR-701U.

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The Trantor TSCSI.SYS DOS driver seems to work the best of all the DOS Drivers I tried. Maybe in a while I'll check out some windows drivers to see if they are compatible but for DOS this is by far the best working driver.


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The Trantor TFORMAT.COM works best for formatting. The only drawback is that it does not allow you to format a quad density disk. It does appear that it will read quad density disks. So with the Trantor driver you can read and write 360K and 1.2MB disks and read 720K. This is different than what the brochure said.

One note on SCSI cards. I tried an Adaptec 1542C, a Future Domain PNP-1630 and a Trantor T-160. The Future Domain card seems to work best. The Adaptec worked fine, but it did not like the TFORMAT Utility that well. The utility would run and format disks just fine, but it would lock up the PC on exit. The Future Domain card did not do this. The trantor card worked really well too, but it wanted to boot from SCSI no matter what so you can't have floppy disks inserted when you boot the computer. I couldn't figure out how to stop if from doing this. So I'm using the Future Domain SCSI card and it works great.

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I added this to my multi-floppy desktop. It's the 13th floppy in that system. haha!


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bolex

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O.k. I can see 8 drives (2x2.88,2x1.2,2x360,and 2 x 8") but what do the other 5 do? :p

There really is no point to the system other than to keep adding floppies. The 4 floppy controllers that I'm using work great as far as the system goes, but are not really good for disk imaging.

In all reality, it would make more sense to have a good controller that passes all the Dunfield tests for disk imaging and have multiple PC's. Specifically if disk imaging is the long term goal. I just wanted to say I built a PC with 14 floppy drives. (The 14th is going in later this week). haha!

I do have to say that the SCSI drives are excellent for formatting and checking disks. The low-level format utility that is part of the trantor driver works amazingly well.
 
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Shadow Lord

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I do have to say that the SCSI drives are excellent for formatting and checking disks. The low-level format utility that is part of the trantor driver works amazingly well.

Interesting, I don't believe there is anything inherently better about those drives then the regular ones (i.e. same mechanism, motor, etc. just the FC-1 addon board). I wonder ifhtey are just better aligned due to a lower amount of use?
 

bolex

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I don't know why. My theory is the SCSI Floppy Bridge was designed for very specific floppy drives, while a standard PC floppy drive has to work with everything. Teac knew exactly what their own drives were capable of doing when designing the FC1 and only specific Teac drives are compatible as far as I can tell. On any floppy that I've had a disk read or format error on (track 0 - disk unusable) my standard floppy controller, I can put in the SCSI floppy drive and it formats it easy. I can then put it back in the other drive, run scandisk, copy to and from and it works like it's a brand new floppy.

I'm sure if I had a better floppy controller, it might perform the same. The Everex 4 floppy controller I'm using as my primary floppy controller does not test very well with testFDC. It's a poor controller I think for disk imaging. I don't think the MCS3201 FDC controller chip on that card works all that great.

Also, I'm comparing to the DOS format command. There are probably better disk format tools out there than just format.com. The TFORMAT command I'm using is a low-level SCSI format utility.
 
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led178

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The Trantor TSCSI.SYS DOS driver seems to work the best of all the DOS Drivers I tried.
And what drivers can still work with FC-1?
I even tried to earn 2940UW ASPI8DOS.SYS 1.36 / TSCSI 4.60 :)
 

bolex

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The ones I used are still available on Microchips's (Adaptec's) site which is the TSCSI.SYS 4.60 driver. I'm using a trantor T160 card, but I tried various early 16 bit Adaptec cards and they all seemed to work fine with TSCSI.SYS.

 
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