16 Dec
1999
16 Dec
'99
10:59 a.m.
On Thu, 16 Dec 1999, Pat Barron wrote:
On Wed, 15 Dec 1999, John Lawson wrote:
>
> In the 11/44 system which is now occupying my evenings... there
[Snip]
The RH11 UNIBUS MASSBUS adapter actually consists of several boards:
M5903 MASSBUS terminal tranceiver
-> M5904 MASSBUS control tranceiver
-> M7294 MASSBUS data buffer and control
M7294-YA Modified M7294 for RH11-C (used on DECSYSTEM-2020)
-> M7295 MASSBUS bus control (RH11-A only)
M7295-YA Modified M7295 for RH11-B
-> M7296 MASSBUS control and status registers
-> M7297 MASSBUS parity control
The appropriate boards live in their own section of backplane.
Ah, so... I have the boards (as marked above) in the unit
currently... just like you have described it.
The RA90 is an MSCP drive; you need a UDA50 to run it. MASSBUS drives are
Yup. I gathered this from the Peripherals Handbook that I fell
asleep reading last night. O Well.. I got the RA 90 for $5 from a
guy at the TRW Ham Swapmeet here in SoCal who thought it was a big
power supply, because the power unit for the drive rides piggyback
on it, and has a big rating plate that identifies it as a power supply.
Thanks very much for your help!
Cheers
John