[Coco] Regarding a cheap floppy emulator

[Al Hartman]

To be honest, the LAST thing I would do is try to use a 1.2mb drive jumpered 
to 300 RPM. It's still an 80 track drive, which writes thinner tracks. You 
won't be able to write to existing 35 track Coco Media without first copying 
the disk to a bulk erased floppy. I'd buy a 360k drive on eBay. I've bought 
three in the last month for under $30.00 apiece. You just have to put in a 
search for 360k drives, and wait. I'd also check an electronics recycling 
center, Freecycle, or Craigslist. If you spot an old IBM XT or PC or 
compatible with 360k drives, grab it!

I was using an old PC Clone case as a case/power supply for four drives for 
my Coco at one time.

I'm trying to buy an FD-502 myself.

Al

-----Original Message----- 

From: Christopher Smith

So, given that I may need to build my CoCo disk system from parts anyway, 
I've been looking at the possibility of emulating one out of two floppy 
drives in hardware.  There is at least one very impressive floppy emulator 
available which will do everything I want, but it's upward of $100 and the 
budget isn't so great for now.  I'm looking at the possibility using a 
Chinese import emulator from ebay.  Supposedly it will emulate a 720k, 1.2M, 
and 1.44M floppies.  Now, of these formats, I'm reasonably sure the CoCo 
won't like any but the first.  That may be sufficient.  Here's what I'm 
considering:

I have a Teac 5.25" drive on order.  It's high-density, but people say that 
these things have an RPM jumper on them which will slow the spindle down. 
You can then either force them to double-density mode or have them function 
as quad-density.  People also say that the quad-density disks will work out 
ok under OS-9.  I'd like to fit a switch onto the density selector so that I 
can force the drive into either double or quad density mode at any given 
time.  So that should make one good drive.

I'm also thinking about trying one of those floppy emulators.  It would need 
to be forced into 720k mode, and would basically work similarly to the 5.25" 
disk in quad-density mode, I suspect.  The downside is that the emulated 
disks would be smaller than usual under DECB, and unless I flipped sides 
there either by attaching another switch that mucks around with the side 
select signal on the cable or in software, I lose half of the space in a 
disk image that I might have still had.  Though, OS-9 should use them at 
full capacity, one would think.  My other problem here is that I strongly 
suspect that this emulator will not have drive select jumpers, so I may need 
to end up clipping pins, or -- who knows what, really -- to get the drives 
in the order I'd like.  Really I think the emulated floppy should be drive 0 
and the actual floppy 1.

Any comments or suggestions on how to do this or why it's a bad idea and 
something else should be done instead? :)

All that aside, I'll still have the problem of housing the drives.  I've 
recently salvaged an old case that had a CD-ROM in it, which should be 
sufficient for a single drive, but I don't really have anything appropriate 
for two drives.  A standard (and as small as possible) PC power supply of 
even 60W or so should do fine for power, I think.  As for the box, I'm not 
quite sure what to do there.  Perhaps wood I could do on my own.  Maybe I 
could have something fabricated out of metal.  Something else?  Any ideas 
here will be welcome as well.


Chris