10 Jan
2012
10 Jan
'12
8:32 a.m.
----- Original Message:
Date: Mon, 09 Jan 2012 22:29:10 -0800
From: Josh Dersch <derschjo at mail.msu.edu>
To: General Discussion: On-Topic and Off-Topic Posts
...
I've created a few floppies from my PC on a
5.25" drive using ImageDisk, I
have been unable to get the FDC to read them (or boot, obviously). I
wasn't 100% sure it wasn't just the setup I have on my PC getting in the
way, hence my latest attempt to use the FDC itself to write the disks.
You don't say which images and whether you're talking about a DD drive or an
HD drive emulating an 8" disk.
Let me say it again: very few PCs will reliably write the Cromemco 360K DD
format, but 8" images written to a 1.2M HD drive (on 1.2MB disks!) are
usually quite reliable. See below.
> You are aware that using a 5.25HD drive as an
8" requires a jumper to
> connect /READY to the FDC's 5.25" interface?
I was not aware, but the 16/64FDC has connectors for
both 5.25" and 8"
drives, I've been using the 5.25" connector and the controller seems to be
able to communicate with it OK -- it has no trouble seeking and formatting
tracks... it just can't read or write them at the moment...
Umm... if you can't read it how do you know it was formatted correctly?
The 5.25" connector normally only supports DD drives/formats (which, as I
said, are notoriously unreliable reading disks made on a PC) because the
/READY signal needed for 8" drives is not available on that connector. To
use the more reliable 1.2M HD drives (360RPM with 1.2M HD disks) (or
3.5" HD drives for that matter) connected to the 5.25" port as 8" you need
to connect pin 34 to /READY (and jumper the drive to supply /RY instead of
/DC). Incidentally, that also avoids the 8" drive issues that Bill and
Amardeep are arguing about.
So, frankly, I'm very skeptical that your 1.2M HD drive is working at all
*as an 8" drive*. BTW, your 300RPM HD drive is also going to be troublesome
if not completely useless.
And of course you have to select the correct drive type in RDOS with one,
two or three semicolons.
I'd be surprised if the 1793 were the problem, especially both of them. The
4FDC had a bad reputation for that, but out of the 20+ Cromemco systems that
I supported (and still have most of) only ONE ever developed problems
reading disks and I never did investigate what the cause actually was.
No offence, but most likely you're doing something wrong; image/disk
incompatibility, wrong type selected, etc. etc.
Good luck!