Info on Amstrad 40095/A / DRMD20A12A MFM HDD

Hi guys, Someone has just donated an old ST506 hard drive to the DiscFerret project... This time, it's an Amstrad drive, with part number 40095/A "DRMD20A12A". Thing is, I can't seem to find any information on it -- and at the very least I need to find out what the CHS settings are in order to create a DriveSpec file. Here are a couple of photos: Top of drive: http://twitgoo.com/2bnvcy / http://i52.twitgoo.com/n7yp.jpg PCB: http://twitgoo.com/2bnvdl / http://i53.twitgoo.com/2cgzc0k.jpg Major chips are: Hitachi HD63B01Y0P SanKen STA435A Hitachi HA13426 CF77143FT SSI 540-3CH S8714 32119.1.1F Hybrids: SC619 and SC628 Text at top corner of PCB near power connector: PY349C Head stepper motor is labelled: TYPE 103-4902-0320 10.5VDC 0.26A 0.9 DEG/STEP LOT NO. 05709I 6035095-1 Form factor is 3.5-inch, half-height (about the same height as a 5.25 HH MFM drive) From what I can gather, it's a 20MB MFM drive, with four heads -- there's a sticker on the top which reads: DEFECT:CYLINDER HEAD0 HEAD1 327 386 426 504 HEAD2 HEAD3 216 (The numbers are handwritten -- badly) There's a second sticker along the edge: W A R N I N G WARRANTY VOID IF THIS SHIELD BROKEN Does anyone have any idea what this thing might be? Thanks, -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/