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Would a Gotek floppy emulator work on my IBM PS/2 Model 80 (8580-A21)?

RootHouston

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I am trying to rescue an IBM PS/2 Model 80 (8580-A21) that uses the standardish 34-pin floppy drive connector with power. I have already replaced the CMOS battery, but now I need to boot a reference disk, and update the CMOS settings to get it working. As usual, the OEM floppy drive that it has seems shot (I've already cleaned the heads), and I might try to do a repair of the capacitors some time, but in the interim, I'd like to use a Gotek floppy emulator that I have to get something going.

According to this site, it is possible to use a standard floppy drive with the PS/2 if you just use a conventional floppy cable and power the drive off the PSU with a molex to floppy power adapter. However, the site mentions the need to change jumper settings on the standard floppy drive to get it to work properly. I know the Gotek has some jumper settings as well.

Basically, does anyone know what jumper settings need to be used in order to make a standard floppy drive work on a later-model IBM PS/2 Model 80?
 
Dave, thanks for the image. It looks like that adapter would provide a slick way to grab power from the existing connector on the planar, but apparently you can just plug a regular floppy cable with a 34-pin connector into the pins that don't supply power, and it will work fine. I plan to grab power from a molex to floppy adapter directly from the PSU. I just needed to know the jumper settings the Gotek would need to use in order to be compatible. It looks like I gained access to that group finally, and someone there mentioned that there should be no need to modify jumper settings on the Gotek to get it to work with the Model 80, so I am just waiting on that molex to floppy adapter, and I will give it a try and report back.
 
I'd like to report that I have successfully configured the Gotek floppy emulator to work with the PS/2 Model 80. Hopefully my experience can help someone since there isn't much info out there for doing this model. First, I flashed the FlashFloppy firmware onto it using this video:


From there, I downloaded the IBM PS/2 Model 70/80 Reference Disk from this site. I was able to plug the standard 34-pin floppy cable that I had into the planar's (motherboard's) 40 pin connector using only the last 34 pins, and the other side into the Gotek emulator.

I tried to close JC and S1 jumpers on the Gotek like another YouTuber with a Model 30 used, but it did not work for me (received an error 601 on POST too). It only worked when I used JC and S0 jumpers. Not sure which machines use what, so try swapping those if it doesn't work the first time.

Here are some pretty important things I learned/confirmed:

  • Watch out with the standard floppy cable while connecting it to the planar. Originally, I ended-up bending some pins there, because my cable's connector was a little too wide. Be careful with this. I was lucky that I was able to bend them back, but if I had broken a pin there, things would've been much worse. Instead of plugging that cable back to the planar, I sanded down the sides of the cable's connector as much as I could using a metal file, and used some compressed air to blow off all the plastic bits.
  • Make certain that you are skipping the planar's first 6 pins with the standard floppy cable. If you do it wrong, you could fry something, since power is travelling through those pins.
  • Use the first drive connector on your floppy cable's ribbon cable At first I had used the secondary connector, and the Model 80 didn't complain, but it still refused to boot from floppy.
  • Using the standard floppy cable only works if you have a later Model 80. You need to use the TexElec PS/2 to standard floppy adapter instead if you have one of the earlier Model 80s with the edge connector. Without looking, I had thought that all PS/2s used this edge connector, and bought that first, but I ended-up not being able to use it.

Let me know if anyone has any questions.
 
I tried to close JC and S1 jumpers on the Gotek like another YouTuber with a Model 30 used, but it did not work for me (received an error 601 on POST too). It only worked when I used JC and S0 jumpers. Not sure which machines use what, so try swapping those if it doesn't work the first time.
Let me know if anyone has any questions.

The JC jumper is only required for (is dependent upon) use of a specific FF.CFG file setting, for ease of switching between interface = ibm-pc/shugart, otherwise it isn't needed.

All PS/2s diskette drives use DS1 drive selection as do many clones, provided there is a "twist" between the B: drive connector (34-way or more straight through from the planar socket) and A: drive connector (with the "twist" between the B: drive's and A: drive's connectors). This "twist" swaps the Drive 1 and Drive 0 signals to the other's positions in the far end connector. Requiring S0 jumpered must mean you only had a straight through (1 to 1) ribbon cable, jumpering the B: drive as S0 then makes that the A: drive.

There are a number of "types" of expected PS/2 diskette drive connector:
1) 40-way card-edge, with 4 embedded power lines at one end (37-40)
2) 40-pin connector (1/2 height), with 4 embedded power lines at one end (37-40)
3) 34-pin connector (1/3 height), with 4 embedded and repurposed power lines
4) 34-pin connector (1/3 height), with 4 embedded and repurposed power lines, electronic eject and security lock/unlock capabilities

3) may come in 2.88MB supporting versions
4) is a 2.88MB supporting version only

The repurposed 34-pin connector lines for power were chosen such that no problems occur, other than loss of certain functions or lack of power to the drive, if an "incompatible" drive is connected.
 
I'd like to report that I have successfully configured the Gotek floppy emulator to work with the PS/2 Model 80. Hopefully my experience can help someone since there isn't much info out there for doing this model. First, I flashed the FlashFloppy firmware onto it using this video:

Hi, very useful information! What do you put on USB stick? rf7080a.img, FF.CFG (if yes, changed interface = ibmpc?) , IMG.CFG or only the ref disk img file? Jumpers settings were on JC and S0 right?

Thank you.
 
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Next day, new time to make it work! Something happened with the stick and it wasn't accessible anymore. Formatted, copied only rf7080a.img and with JC and S0 jumpers worked! Only observation is that I have to insert it AFTER the PC starts and F-F is displayed. WhatsApp Image 2021-10-22 at 09.40.24.jpeg
 

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You need to read and understand the FF.CFG desription more fully. The DEFAULT filenames are DSKA0000.IMG through DSKA0999.IMG unless you override the operational parameters via an FF.CFG file, as appropriate.
 
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