Dec RQDX: What kind of chips on it?

Warner Losh imp at
Mon Jan 4 18:04:47 CST 2021

On Mon, Jan 4, 2021 at 3:40 PM Chris Zach via cctalk <cctalk at>

> 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 at 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

18 sectors seems odd. The Rainbow had a limit of 16 sectors, but that may
have been due to other reasons... It had a WD10xx controller.


More information about the cctech mailing list