5 Jan
2014
5 Jan
'14
1 a.m.
From: Glen Slick <glen.slick at gmail.com>
Date: Sat, 4 Jan 2014 12:02:32 -0800
Subject: Re: MFM Control Signals and RD disk size
On Sat, Jan 4, 2014 at 11:16 AM, emanuel stiebler <emu at e-bbes.com> wrote:
This was posted years ago for the RD53 - Micropolis 1325 or 1335:
Unscrew the two screws holding the circuit board to the bottom of the drive
and carefully lift it up. Along one edge of the circuit board you will find
a place where it would appear that a resistor should be -- this place is
marked
R7. Solder a jumper into that spot to make this drive into an RD53. Set
the
drive select jumper to DS2 and you should be in business.
--
Michael Thompson
On 2014-01-04 11:59, Robert Jarratt wrote:
How does that match with this information, if it is correct, that the
MicroVAX 2000 disk recognizer works for the set of known disk drives
even if the disk came from a different system and has no DEC specific
information or formatting on it currently?
http://home.iae.nl/users/pb0aia/vax/fmtbob.html
"The standard DEC drives that are supported in the VS2000 and their
industry equivalents are:
RD54 - Maxtor XT-2190
RD53 - Micropolis 1325 or 1335
RD31 - Seagate ST-225
RD32 - Seagate ST-251-1
If you have any of these standard drives you can simply plug it into
your 2000 and the ROM formatter will automatically recognize the drive
types. I've never seen this fail, even if the drive has never seen a
DEC machine before, or even if the drive was previously formatted in
a PC."
So how does it do this when the disk is yet to be
formatted? In other
words,
when it formats the disk how does it know what size the disk is?
DEC drives have this information in a special area of the drive.
If for exmaple, the MV2000 finds this blocks, it formats to exactly this
specs. You see this, if you go into the MV2000 diagnostics.
All other drives, you have to enter the specs manually ...