10 Apr
2024
10 Apr
'24
7:22 p.m.
Jonathan Chapman via cctalk wrote:
I spy two AM2901 4-bit slice ALUs, two N82S181 1024x8 PROMs, three
AM2911 microprogram sequencers, and an SN74150 3-to-8 line decoder. This
thing is doing arithmetic.
Carlos.
1. I have read
that the card and the drives were compatible with the dec rx02 drives. Why would the CRDS
even bother to redesign a card where DEC had perfectly good working ones? Anyone know if
there is any value in keeping the FC-202 or just keep with the DEC cards?
A lot of
the third-party controllers could talk to Shugart-style 8" floppy drives. They can
also usually *format* the diskettes, which the RX01/RX02 systems from DEC can't do --
you have to use preformatted media. This isn't a *huge* deal since RX01 is just IBM
3740 and you can format it on CP/M boxes, with ImageDisk, etc. There's an XXDP utility
to upconvert RX01 media to RX02, which is M2FM and very few things can work with it.
Apparently a lot of small shops kept a CP/M box just for the task, the Alspa ACI-2 I had
was supposedly used like that.
2. Any idea on that other card?
https://w2hx.com/?prefix=x/What-Is-It/PDP-11-Thing/Board1/
Looks like a non-DEC
Qniverter -- QBus to Unibus converter. If that's what it is, you'd plug your
Unibus cable into that pair of connectors on top and run it to whatever Unibus device you
were wanting to talk to, potentially another backplane full of Unibus stuff. Commonish
upgrade on e.g. CNC machines that were originally controlled by a PDP-11/05 or something
in one Unibus chassis, with another Unibus chassis full of machine-specific cards.
Thanks,
Jonathan
.