5 Mar
2002
5 Mar
'02
midnight
At 11:26 PM 3/4/02 +0000, you wrote:
Right. That's a MDS DDS (that's what mine is marked). The older one is
a MDS-2DS.
I can understand that but I'd think that they would at least give the
jumper/strap/cuts needed to configure the drive for their system.
Actually I preferr the old way of documentation where they gave you the
OEM manufacturer's manuals. They're a lot more complete than the
abbreviated versions that they usually include in the manuals.
Agreed.
Joe
At 07:58 PM 3/4/02 +0000, Tony wrote:
There also seems to be a double density system using the controller from
the later system (same pair of mulitbus cards) but the older drive
cabinet (drives standing vertically. I have that on my MDS800.
I happen to have the 'Intellec Series II Microcomputer Development System
Double-Density Diskette Subsystem Schematic Drawings' here. (Phew, what a
title). I am not sure if this is the same unit that you have, but it
might provide some information. Unfortunately, I don't have any
information on the drives themselves -- there are no schematics or link
settings given. I do have info on the 2 multibus cards (controller), the
PSU, and the cabling.
I have that manual for both the MDS 720 drive (two drives laying
horizontally and using a double density controller) and for the older MS
2DS system (two drives mounted vertically and using the single density controller) and NEITHER of them says one word
about the drives! It's
That's quite common, actually. Most of the time the drives are standard
units with their own manuals. Often the complete documentation set for
the device includes the service/technical manual for the drive.
For example, I have the manual for the floppy disk system for the Philips
P851 (etc). The Philips manual covers the controller (schematics,
microcode source, etc) and the drive PSU. There's a separate CDC manual
for the floppy drives. I think there's a commant somewhere in the Philips
manual saying what version of the drive is used and how to set the links.
I just bought a Fluke 1722 service manual and was pleasantly surprised to
find complete copy of the Ball manual for the monitor and a complete Tandon
manual for the disk drive. Those alone made the package worthwhile.
amazing to me that intel would go to the level of
detail that they do but
completely ignore the drives!
J1 P1
(cable) (drive)
Odd # Odd # Ground
2 46 Read Data
4 2 Not used (or even connected?) >> Not connected
6 42 Track 0
8 20 Index
10 16 Track <43 (is this really track > 43 ???) >>My
docs say "< 43" also.
Shugart says that pin 16 is an "alternate I/O" connector and it can be
used for whatever the manufacturer decides. I've checked and it does
Sure, and it appears Intel used it for Reduce Write Current or similar.
I don't think you need to worry about that.
The controller seems to use a
1-of-n active low drive select scheme (2 DS lines per drive cabinet
cable), so you can just link each wire to a particular drive's active DS
line.
That's what I thought but I suspect there may be more to these. Shugart
had some odd options available like "seek without selecting a drive" and
It's not going to use that, if only because the drive signals are bussed
together as normal. Step and Direction do not go to each drive
individually. Look at the schematics of the controller card. In just about
every case the outputs (controller to drive) carry exactly the same
signals for the 2 drive cabinet connectors (there's typically a pair of
drivers with exactly the same inputs signals). The inputs (drive to
controller) are logically ORed for the 2 cabinets (often by '132s --
remember the drive signals are active low). So just about all signals
must be gated by the drive select line.
My guess is that ready is _not_ gated by DS. That's why there's a separate
wire for each drive ready line back to the cotnroller, linking them to a
'153 mux.
"seek without loading the head" and
this may be using one of those and that
Interestingly there doesn't seem to be a head load signal on the signal
adapter PCB, so possibly it uses head-load-on-select or similar.
> may explain why they did it this way.