How come there aren't any 5.25 external USB floppy drives?

[carlsson]

Perhaps the DIY solution in form of the Greaseweazel would be possible to adapt with routines for reading the tape drive, but I wouldn't hold my breath that it works right out of the box. The other, more expensive closed source solutions that are nicer packaged are less likely to support it. A cheap, ready made mass market product is more or less out of the question IMHO, this is tinker land for die hard hobbyists.

[Krebizfan]

The USB97cfdc from SMSC was intended to provide the capability to connect a floppy tape drive to USB.

Quote

Although not required for standard floppy operation, provisions for 16K bytes of external buffer SRAM, in addition to
that included in the USB97C102 core, is also provided for extended applications, such as tape drives and for other
special applications.

Finding a 25 year old chip and the necessary driver source code which would need modification to successfully attach a tape drive seems unlikely. 

[moose83]

Tandy Radio Shack 25-1087 5.25 1/4 External Floppy Drive 1.2Mb

https://www.ebay.com/itm/294152413847?hash=item447cd9a297:g:g30AAOSwse1gjJm0

Cost $295

 

 

 

 

[Krebizfan]

The Tandy 25-1087 is a parallel port floppy drive not a USB drive. The included power cable seems to be hacked from a SATA power cable which might be a bit challenging to attach to vintage hardware. 

[Keatah]

It's a spam post.

 

[carlsson]

Spam or not, the claim that an external 5.25" drive would draw so much power that 12V @ 3A is not enough seems worth analyzing further. It would suggest a single drive draws around 35-40W or more.

 

For comparison, these numbers for a Panasonic JU-475 (which is different from the Epson SD-600 used in the external TRS drive) claim it at most consumes 9W which is more in line with what I would expect. I would have to look up more numbers, but I can't imagine that the Epson drive uses 4 times as much power as the Panasonic one does?!?

Edited July 12, 2021 by carlsson

[+OLD CS1]

<- Dummy.

[glurk]

So today, I made one of these - minus the USB part, though.  Didn't want that anyways.  I took an old "Magicspin" external CD burner - Google 'Magicspin External' for pics - and put in a Tandon TM65-2L half-height DSDD drive.  Not an easy project, took all day.  Here's a pic:

 

 

Basically involved lots of Dremel work, cut a hole for the external floppy connector, cut off the IDE and USB parts of the board inside, rewired, made a card-edge to male ribbon cable, wired it all up, etc...  Had to leave a 3.3 supply part of the board intact so the little green LED near the back of the case would still work.

 

The PS that came with the burner supplies 5V & 12V at 1.5A each, more than enough.  And I still have the CD burner that came in it.  Tested with both my TRS-80 Model III and slaved off my Atari Percom drive.  Works great, I'm happy with this one.  I had been looking for a 5.25 half-height enclosure, couldn't find one, and then had the idea to do this.  I think it's cool, LOL!!

 

EDIT TO ADD:  If I want to change the drive select, I have to pop the case back open.  No big deal, but maybe I'll put an external DIP switch in it or something.  I think they make rotary dip switches??  That would be cool, set it from 1-4 with a turn.

 

Edited September 12, 2021 by glurk
Addition

[wierd_w]

Hmm..

 

Personally I would have used an external 5.25" generic SCSI CDROM enclosure.  The size of the old SCSI-1 external port is VERY close to the size of an old-school external floppy diskette port cable connector.

 

I would have made a suitable adapter on some protoboard (with an IDC header on the inside, a DB37 female port facing out) aligned with the SCSI-1 slot.

 

It would require almost no cutting, and only some modest soldering. 

[glurk]

Well, yeah, but this cost me hardly anything.  Got the drive on eBay for about $55, got the CD burner at a flea market for $15, and already had the cables, connectors, etc...  Plus, it was kinda fun.  And this thing is as small as it can be, with the switch and power input in there it's packed tight.

 

Now with a SCSI enclosure, there probably would be room for an actual USB-Floppy board, pretty sure that Greaseweazel thing could be put into the right enclosure.  But my little project was super cheap, and I have little money, hahaha....