esdi hard drive identification

Jay, 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 NOTES: *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. Allison <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? < <Thanks! < <Jay West <