5 Jan
2021
5 Jan
'21
3:47 a.m.
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
<cctalk at classiccmp.org> 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 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
Thanks!
CZ