On 4/22/22 21:48, Fred Cisin via cctalk wrote:
On Fri, 22 Apr 2022, Bill Gunshannon via cctalk wrote:
As another person with a desire to be able to read/write/create
disks of different sizes and formats I have found this interesting.
So the question, then....
How hard would it be to make a floppy disk interface using an Arduino
or even RasberryPi? If you could do that the choices of interface
to a PC opens up quite a bit. It would never be like having a floppy
hanging off the PC, but then none of the formats I am interested in
are grounded in the PC anyway and utilities would need to be written
to access them.
comments?
There are a LOT of possibilities.
At one point, one of my associates was playing around with various "PC
on a board" motherboards that were 5.25" floppy drive size. ("Quark"
80186 equivalent of an Ampro Little Board) He mounted it with spacers
on a 5.25" drive, in an external case. It was a complete PC, that
looked like an externala drive.
His primary purpose was to build dedicated PC industrial data
acquisition units. (Elcompco made several data acquisition systems that
interfaced directly with banks of elevators) With trivial some software
on it, it could connect to a "real" PC and do disk I/O.
I once saw an extremely similar commercial product being marketed for
Macintosh that was an "external 5.25" floppy drive that can read PC
diskettes". It was an Ampro Little Board on a drive, with software for
letting the Macintosh access files on its disks. They avoided
mentioning what was inside the box, and presented it as a Macintosh
special external drive. (similar to the Macintosh version of Video
Toaster having an Amiga in the box)
They added software to it to handle some CP/M formats. I was amused
that among the formats that they supported were a format where I had
misspeled the format name (due to customer handwriting), and they copied
my mispelling, and they had a format that I had put into XenoCopy for a
friend to handle his on-off prototype machine that never went to market.
(a non-deliberate Mountweazel poach flag copyright trap)
You could build a small box with a drive and either a from scratch
controller, or a 765 (or better yet, a WD 179x), that connects to PC.
In that box, you could put almost anything that could work with the FDC
and communicate.
But, as a first step, and "proof of concept" for an external box, why
not just start with a 5160 or 5170, running software and communicating
with your host PC? Then, later, you could replace the 5160/5170 with a
more compact dedicated bespoke device.
(OK, I'm still thinking in terms of the days when people were upgrading
PCs and throwing out the old ones, so that an XT cost NOTHING)
Your right about all the available options. Somewhere around here I
have a couple of P112 SBC's. I wonder what the floppy controller in
that can do? I am pretty sure it claimed compatibility with CP/M 8"
disks. If so it can probably handle all various 5.25" formats as well.
Looks like I may have a number of things to play with while I spend
my summer stuck in the house.
bill
