>From: Gunther Schadow <gunther@aurora.regenstrief.org>

>> MASSBUS I am not to sure of, but it is a CARD BUS, similar backplane
>> to the SBI. Yes, used mainly for storage. I have a MASSBUS disk 
>> controller. I would love a RMxx drive or 2!
>
>Ohmygawd, yet another card bus! Where is that physically located? Yet
>another cabinet? What is the list of cards one can stick into the 
>MASSBUS?

I don't know what he meant by this.  Massbus is a drive bus, using thick
round cables with big 120-pin connectors on them.  I don't know what the
11/78x Massbus adapter looks like physically (I suppose it's called RH780),
but it shouldn't matter, the Massbus side always looks the same.  The RH
is basically a host adapter, like SCSI but of course every single detail
is different.  But most of the brains are in the drive, and you can plug
in any mixture of drives (whether the OS supports that is another story)
and there's a drive register that the host can read to find out what the
drive type is.  Drives are:

Disks:
RM02	2400 RPM version of RM03 (3600 RPM), mainly for PDP-11s w/RH11
RM03	67 MB, 5 platters, hacked/rebadged CDC 9762
RM05	256 MB, 12 platters, hacked/rebadged CDC 9766
RM80	124 MB Winchester (R80 drive mechanism with near-SMD personality board)
RP04	88 MB, 12 platters
RP05	88 MB, 12 platters (same packs, different drive vendor)
RP06	176 MB, 12 platters
RP07	516 MB Winchester

Tapes:
TE16/TU16  800/1600 BPI, 45 IPS
TU45	800/1600 BPI, 75 IPS
TU77	800/1600 BPI, 125 IPS
TU78	1600/6250 BPI, 125 IPS

John Wilson
D Bit