4 Oct
1999
4 Oct
'99
7:45 a.m.
--- allisonp(a)world.std.com wrote:
RXV11 is only compatable with the DEC RX01. The H11
Floppy used a Heath
interface. If you use the heath floppy with RXV11 nothing happens.
OK. I'll go back to the card and get it working. Worst case, I'll pull
all the sockets and solder in machine-pin ones. I'd rather not; it's lots
of work. I observed substantial oxidation of the plating on the ICs I did
remove and test (I can't test DEC bus chips with my IC tester, only CMOS,
TTL and DRAM).
Get manuals for it! you'll save pain.
Any pointers on where to lay hands on H-11 docs?
> Finally, eventually, I want to get original stuff
back into this box.
The original was DLV11 compatable but it was HEATH
design, not as durable.
It looks dodgy, but then most of the Heath stuff looks less solid to me.
The H11:
DEC M7294 11/03 (Quad width card with 4k ram on board)
Got it.
This was the ONLY dec made card in it.
Heath Memory, several version were available 4k early, 16k later.
Don't got it. I have several 32Kw and 128Kw boards from 11/23s, etc., and
a few 4kW and 16kW boards from my LSI-11s (knee-high formica-topped rolly
DEC cabs w/RX01 and 11/03 inside).
Heath floppy controller/interface card.
The last one is interesting as the heath disk <8"> used a z80 in the
floppy box to do the low-level disk interface and the ribbon went back
a simple interface that was mostly a parallel card.
The card itself is about as simple as any Qbus card. It is, I take it,
supposed to be nominally RXV11 compatible from a driver standpoint, yes?
If not, then that's part of my problem. I do boot, the disks to appear to
read in an OS, then the system hangs, but that could be as a result of my
card only working if it is *not* at the end of an unbroken grant chain (with
a gap in the bus, the disks read but the system does not boot; without a gap
in the bus, the CPU does not even bring up the boot message).
It was RX01 compatable in one mode and had a HEATH
specific mode.
Software or hardware selected?
The drives were known for clamps that died with age
and heat load pads that
fell off.
So far, the only problem I appear to have is that the belt on DX1 has either
broken or fallen off. The motor is turning, but not the hub. I haven't
pulled the drive to check yet. On the bright side, the mechanisms appear to
have a 50-pin edge connector, suggesting that they are standard from that
standpoint. I expect that the hub motors are either 110V or 24V.
It could do one thing a RX01 could not, low level
format a blank disk.
I did spot the obvious format switch on the front of the disk unit, but no
idea how to use it. I now wish that I'd picked up a couple more boxes of
media from a friend's business about eight years ago. He had a pallet of 8"
disks that he was selling for more money that I was willing to pay.
Eventually,
he gave me a case - my choice. I grabbed a 24" long box full of pre-formatted
disks, the only one on the pile. When he disposed of the remainder, I didn't
make a trip out there to grab any boxes. :-(
At some point I plan to assemble a H11 system. I have
11/03 cpu, RAM,
serial cards and backplane from one.
One of the gems I have in the Heath pile is an unassembled backplane. I don't
know if all the connectors are there or not and I don't have a second case
for it, but I've got at least part of one to "attract" the rest of it.
-ethan
Allison
=====
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