Need Shugart 851 manual

From: Joe <rigdonj_at_cfl.rr.com>
Date: Tue Mar 5 08:00:03 2002

At 11:26 PM 3/4/02 +0000, you wrote:
>>
>>
>>
>> At 07:58 PM 3/4/02 +0000, Tony wrote:
>> >
>> >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
>
>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.


   Right. That's a MDS DDS (that's what mine is marked). The older one is
a MDS-2DS.


>
>> 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.

   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.


>
>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.


   Agreed.

   Joe
Received on Tue Mar 05 2002 - 08:00:03 GMT