I’m not sure where i read it, but i’m pretty sure the main “brains” of the RQDX2 is a T-11 (PDP-11 FALCON) chip, and that does the negotiations between disk and system. I don’t know if it’s the same for the RQDX3, but i’d suspect not, as the incompatabilities between the 2 and 3 are probably due to a controller redesign. Though i really am no expert when it comes to disk controllers, and barely qualify as an amatuer with QBUS PDP-11’s in general!
I have a suspected faulty, but never tested (water damaged) RQDX2 i have pulled from a MicroPDP-11/23 i have been restoring. I don’t know if it’s any use, but i’m sure i can let it go for a pittance as long as you’re located in the UK > On Jan 4, 2021, at 10:40 PM, Chris Zach via cctalk <[email protected]> > wrote: > > Can someone check to see if a RQDX2 used the Western Digital chips to > interface to MFM drives? Reason I'm asking is the MFM emulator can identify > an RQDX3, and also a Pro/350 controller but this particular RD52 I have > (which was verified by me to run Digital Mumps) is reading as: > > root@beaglebone:~/mfm# ./mfm_read -a > Board revision C detected > Found drive at select 3 > Returning to track 0 > Drive RPM 3525.4 > Matches count 36 for controller WD_1006 > Header CRC: Polynomial 0x1021 length 16 initial value 0xffff > Sector length 512 > Data CRC: Polynomial 0x1021 length 16 initial value 0xffff > Interleave mismatch previous entry 0, 9 was 1 now 0 > Selected head 8 found 0, last good head found 7 > Read errors trying to determine sector numbering, results may be in error > Number of heads 8 number of sectors 18 first sector 0 > Unable to determine interleave. Interleave value is not required > Drive supports buffered seeks (ST412) > Disk has recalibrated to track 0 > Stopping end of disk search due to recalibration > Number of cylinders 512, 37.7 MB > > Thanks! > CZ
