5 Aug
2000
5 Aug
'00
2:16 p.m.
Kevin Schoedel wrote:
Jerome Fine wrote:
Jerome Fine replies:
Probably both - because the BA23 already has termination, I do not know if
the M8012 will function correctly in a BA23 box. And an 8" floppy from
DSD is not a speed demon - well no 8" floppy is a speed demon.
Actually, unless you are a PDP-11 hardware hobby person, an 11/23 is not
a great CPU to have fun with. And with just a floppy and 64 KBytes, I would
rather run PDP-11 software under an emulator on a PC. Mind you, I have
a number of M8044 boards to trade if you have something.
If the 11/23 is a dual board, you may have a bit
of a problem in the BA23
since the BLUE box was designed with boot boards that might not be
compatible with the BA23.
Because the BA23 has termination, or because it's a
22-bit backplane, or
something else? The bootstrap is an M8012-YA (BDV11)
terminator/bootstrap, and neither it nor the other option cards (M8044-HD
64Kb, DSD floppy controller, M8043 async) connect the pins for bits 18-21
(BC1-BF1). The CPU is a dual-width card, and has no apparent revision
marked, so I guess I should assume it is the 18-bit version. All else being equal (i.e. provided it works) I'd
prefer to keep the
system in its original enclosure anyway, that is, more or less close to
its previous working configuration.
Everyone to their own taste. I am a software junkie, so I do not really
appreciate this hardware configuration - rare though it may be.
As I found it, the arrangement of cards has gaps,
unless the backplane is
*really* weird. The backplane itself is MDB model MLSI 40328 -- anyone
know the layout?
If I remember, Transduction used a hex back plane modified to be a
Qbus
interface with a serpentine use of the "extra" slots. But I can't remember
the order. The only non-obvious card in the system is an MDB
DR11B... is this a
parallel interface?
Probably. MDB boards were usually named by their DEC
counterpart.