6 May
2009
6 May
'09
5:22 a.m.
On Wed, 6 May 2009, Dave Dunfield wrote:
I'm not sure what you mean by "mapped as drive D:" - Is this with the DOS
driver?
Actually, the loadable drive and/or the ROM. With the internal controller
disabled, the Compaticard ROM maps units 0 and 1 (5.25" drives) as A: and
B:.
The Compaticard IS NEC 765 (or indistinguishable copy)
Then I'm at a loss as to what the problem is. I can configure the system
such that the Compaticard is the primary controller (disable the on-board
FDC in the BIOS). The first 8" drive is unit 2 (in 0..3) and mapped as
drive D:. I did try lying to IMD and telling it that drive was 1.2, but
testfdc immediately returns an error without anything obvious having
happened. Unit 2 (in 0..3) would be C: for ImageDisk (Like Chuck
suggested
earlier, ImageDisk's A-D represents units 0-3 on the primary floppy
controller - NOT any sort of OS mapping).
Normally I read A..D as being A: --> D: FWIW, that's the way 22Disk and
Teledisk present things. If you're saying that 'C' in IMD corresponds to
unit 2 regardless of DOS logical mapping, then that's news to me. That
was what frustrated me so much when I first fired up the program! I was
thinking that I'd have to pull the hard disk out to get the two 8" drives
mapped in as C and D so they could be "reached" from IMD.
Since I have a hard disk in the bench computer, I was getting A: and B: as
units 0 and 1 on the Compaticard, C: as the hard disk and D: and E: as
units 2 and 3 (8" drives) on the Compaticard. As you surmise, this is
with the CC4.SYS driver loaded.
I'd recommend NOT using any extra
drivers with ImageDisk (it talks directly to the hardware, and external
drivers can interfere with that if they are triggered on an interrupt).
I will try that.
In the IMD
application itself, I can select format and it loads the heads,
pauses a moment and returns a "write protect" error.
That's about when I threw in the towel. The drive and card work perfectly
under Teledisk, 22disk, etc, etc. and I was able to write a usable boot
disk on it after a kind list member sent me a TD0 image.
Here's some things to try:
- Does imagedisk work OK with standard PC drives on A: or B:
- If not, then the controller is probably not a standard PC controller.
(Does it work at all without special drivers loaded?)
- If yes, does it work with the standard drive on C: or D:
- If no, then the drive 2-3 selection is probably different from the
one implemented in ImageDisk (this is non-standard)
I'll try that this evening.
- If yes then it may be the 8" drive
configuration - perhaps the
Compaticard wires it differently that I do (details of my 8" connections
are in the help)
I kludged together that adapter out of a pair of cables (couldn't find a
sacrificial 5.25" drive), but even on the motherboard floppy controller
it's not working properly. Goes through the motions (head-load, seek) but
throws errors on anything involving data transfer. It's possible that the
drive jumpering (for Xerox 820-II) is the problem - or more likely a bad
connection somewhere. The drive being used is NOT the one(s) attached to
the Compaticard. I'd have to disassemble the case in order to try those
(1/2-height Mitsubishi's).
This is a red-herring, I'm sure. Will take another stab at building the
adapter when I find a dead drive. Now that re-cycle mania has taken hold
in the US, everything, but EVERYTHING goes into the crusher (or whatever
they do with electronic junk). Drives are getting very hard to find and
expensive, so I'd rather not chop up a good one :-(.
- Since you now have good media ... can you READ a
disk in the 8" drive
with ImageDisk?
Will try this evening.
Steve
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