esdi hard drive identification

From: Allison J Parent <>
Date: Sat Sep 4 21:45:08 1999


First the RQDXn series are NOT ESDI. They are vanilla MFM. So the common
drives that work are:

 ST225 RD31 20mb C/H 615/4
 St251 RD32 40mb 777/6
 Quantum D540 RD52 30mb 512/8
 Micropolus 1325 RD53 70mb 1024/8
 Maxtor 2190 RD54 159mb 1224/15

*ST251 are generally terrible for reliablity, The D540 is a better
drive and much faster.
*M1325 (the 1300 series!) are prone to problems with heat and age.

The Cylinder and heads were given as a guide to picking other drives that
may match.

With the right cables and all a RQDX2 addresses 1 RX50 and two RDxx drives
or 1 Teac fd55F(or GFR) plus 3 RDxx. In this case the TEAC drive is
jumped to run as a single RX50 (slow spindle and single sided).

Others may be possible but you will need the X11 formatter to make it work.


<One of the surplus stores in my area just got in a load of 5-1/4 form facto
<hard drives. They look just like the ones my PDP-11/73's use (RD51 or 52,
<can't recall). I believe my controller is a RQDX2, not a RQDX3. My drives
<are 30mb.
<I was wondering, is there an easy way (short of looking up the model
<numbers) to visually determine if any of the drives are ESDI and might wor
<with my 11/73?
<Jay West
Received on Sat Sep 04 1999 - 21:45:08 BST

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