View Full Version : IBM 6181682XM and external floppy

June 18th, 2016, 10:38 AM
Before I fry anything... surely this must fit my IBM 6181682XM perfectly?

Oh, and there's a 3.5 / 5.25 switch on the back so, it's "emulating" a 5.25" drive or what? How?


June 18th, 2016, 12:14 PM
Could you provide a picture of the switch on the back? It seems unnecessary.

June 22nd, 2016, 10:40 AM
Yep, here is a picture of the back.

Main question is, will it fry?


June 22nd, 2016, 11:23 AM
I don't know for certain. I suggest opening the external enclosure and checking how it is cabled. Seeing wires running from the data cable to the power plug on the drive inside the enclosure would be a definite clue.

I don't see a separate power cable suggesting the drive gets power over the data cable. IBM XT floppy controllers generally do not supply power over the data cable; enclosures were expected to have their own power source. I suspect the drive won't work (no power). Modifying cables to get that power across can result in mistakes that will damage the hardware. If you try, make sure to pass the wiring to someone else to double check that the right pins are getting power.

Sorry, I only can provide conjecture. Maybe someone reading this thread can provide a better answer.

June 22nd, 2016, 12:45 PM
There were a number of replacement floppy controllers during the XT/AT early 386 era, such as the Sysgen Omnibridge, the Micro Solutions Compaticard, etc. There were also "switch" type adapters that could expand your 2-drive controller to 4 drives by providing support for extra drive select and motor enable outputs. Many had options to provide +5 and +12 volts via unused lines in the DC37 connector. Unhappily, there was no standard for these; the Micro Solutions cards even included jumpers to configure the output to the power pins to match an existing drive.

Bottom line is that you're going to have to open the box and buzz out the power lieads to the connector. to figure out what you've got--and then decide what you'd like to do about it. The 5150/5160 floppy adapter does not supply power via its DC37F.