[comp.sys.dec.micro] 360K floppy on a Rainbow ?

tom@astro.as.arizona.edu (Thomas J. Trebisky) (11/22/90)

I am wondering what people know about putting an IBM style 360K 48tpi
double sided drive on a Rainbow and getting software setup to read/write
disks to exchange with a PC-XT running MSDOS.  I know commercial products
once were / still are ? sold to do this.  I have a suitable drive sitting
around, so is it just a matter of putting a ribbon cable from the C/D
connector on the floppy controller, and running it to the drive?
Any special tricks with the cable?  Where can I get the software to then
make it work (source code for an installable driver would be the ultimate
thing to track down).  My machine is a PC100B running MSDOS 2.5 (I think 2.5)

Maybe this has appeared here before, I have only read this group for maybe a
week.		Any help or advice will be much appreciated.

imp@marvin.Solbourne.COM (Warner Losh) (11/24/90)

In article <512@organpipe.UUCP> tom@astro.as.arizona.edu (Thomas J. Trebisky) writes:
>I have a suitable drive sitting
>around, so is it just a matter of putting a ribbon cable from the C/D
>connector on the floppy controller, and running it to the drive?
>Any special tricks with the cable?

No.  Straight through connection.  Just get you two 34 pin ends and
some ribbon from Radio Shack and clamp them together.  Make sure that
the arrow points to the same piece of wire on both ends.  DEC's cables
were shielded to within an inch of their lives, but I have run a 3.5"
floppy w/o any problems.

If you don't have an SS drive, then you may need to strap edge (or is
that pin) 34 "high" (a small wire from that pin to the +5V on the disk
drive's PC board should do the trick).

>Where can I get the software to then
>make it work (source code for an installable driver would be the ultimate
>thing to track down).

I know of two sources for this stuff.  One is to get the diffs to the
2.11 DOS BIOS from any BBS.  They were done by a Richard Thompsen and
are available from lots of places (even drycas.club.cc.cmu.edu).  This
allows you to have double sided disks on the Rainbow, but I don't know
if it will let you have IBM disks or not.  I rather think not, but I
have not typed in the BIOS listing completely yet to try out his
changes.  You will need to get a 2.11 Rainbow Technical manual to do
this (No, I don't even know where to get one).  The BIOS listings that
I am using are from the CP/M Technical manual and seem to be just a
little bit different than what is on 2.11 (of course, my disasembler
could be flaked out).

The secon source is to get someone who has SS software to sell/give
you the I drive driver.

There is a third source, but it isn't available yet.  This driver
would be available in source form and freely distributable.

>My machine is a PC100B running MSDOS 2.5 (I think 2.5)

Probably 2.05.

Warner Losh			imp@Solbourne.COM	w:(303)678-4748
--
Warner Losh		imp@Solbourne.COM
How does someone declare moral bankruptcy?