3 floppy drives possible in a 5150?

[Shadow Lord]

Hi,

Just wondering if it would be possible to have three floppy drives in a 5150 using IBM parts only. I.E. Two IBM floppy controllers and a 5161 expansion unit for housing? Or do you need a 3rd party controller like the compaticard? Thanks.

 

[Chuck(G)]

Why not just plug an external floppy box into the DC37 connector on the back of the floppy card so generously provided by IBM?

It is possible, using third-party software and hardware to run a secondary floppy controller on a 5150, but it's not simple. A lot of direct-access software depends on port 3Fx, IRQ 6, DMA 2 (certainly the BIOS does) allocation to floppy drives. That survives to the present, where southbridge and "Super I/O" chips give no alternatives as far as resource allocation goes.

 

[mbbrutman]

The IBM PC 5150 supports four floppy drives - 2 internal and 2 external. That is what the 37 pin port on the back of the floppy controller is for.

Look for the IBM 4869 external floppy drive. A double density version will work directly.


Mike

 

[Shadow Lord]

Thanks to both replies:

1. Chuck(G): I remember you mentioning before (in another thread) that IBM did not produce an internal to external enclosure for their full height drives, leaving that up to others. Do you have any names, recs for searching.

2. Mike: Thanks for the info. I want to try and keep the look original if possible. the 4869 matches the PS/2 nicely (as it is meant to do) but for a 5150 it is out of place.

 

[Chuck(G)]

Well, there were Taiwanese-origin external boxes that included power supplies for full-height drives that matched the 5150/60 case design. I've still got one that I use for a full-height backup tape drive. They were common in the mid-80s, but I haven't seen any lately.

 

[Eudimorphodon]

I'm pretty sure WeirdStuff in Sunnyvale, CA still had some external drive boxes aping the case design of the 5150/60 kicking around in their back room last time I was there, but there's no telling if they might of gotten around to finally scrapping them yet.

 

[Shadow Lord]

I'm pretty sure WeirdStuff in Sunnyvale, CA still had some external drive boxes aping the case design of the 5150/60 kicking around in their back room last time I was there, but there's no telling if they might of gotten around to finally scrapping them yet.

Thanks. I sent them and email. Lets see what happens. When did you see the external boxes? Thanks again.

 

[Eudimorphodon]

It was probably a little less than a year ago but unfortunately I can't really be more specific than that. They've had a shelf full of assorted external drive boxes in their "As-Is" back room for years and it's possible that I could be remembering one from an earlier occasion. I'd offer to take a look for you next time I go but I suppose it's obvious I don't get over there often.