15 May
2014
15 May
'14
3:16 p.m.
On May 15, 2014, at 5:12 PM, Mark J. Blair <nf6x at nf6x.net> wrote:
On May 15, 2014, at 10:26 , Christian Gauger-Cosgrove <captainkirk359 at gmail.com>
wrote:
The way it works for my CMD CQD-220 is that you can have its
bootstrap ROMs respond to 1773000, the typical bootstrap location,
or 1771000 (my recollection). It's jumper-selectable (including
no bootstrap access at all). Fortunately, my 11/23+ has MSCP boot
in its ROMs, so I don't need to worry about it.
- Dave
On 15 May 2014 13:08, Cory Smelosky <b4 at
gewt.net> wrote:
I believe that my system's backplane is the 18-bit variety, as opposed to the 22-bit
variety. I think that the UC07 card will support both 18 and 22 bit busses. If I
understand correctly, the processor directly addresses 16 bits but uses some sort of bank
mapping register(s) to address additional bits, but I'm not positive about that.
In any case, I'll find out for sure whether it works when I try it. My SCSI card is
still in transit, but hopefully I'll know in a couple weeks or so.
My system's bootstrap ROMs don't include code for MSCP-compatible controllers,
but the UC07 is supposed to have its own built-in bootstrap. I don't know if I'll
still have access to the original bootstrap ROMs after I jumper everything for the UC07
bootstrap. Maybe I'll need to route one or more jumpers out to some external
switch(es) to let me boot from the RX02 when desired? The /03 is 18-bit right? The SCSI adapter I have
has an option for 18-bit addressing.
The LSI-11 and LSI-11/2 (PDP-11/03, in other words) processors are
only 16-bit addressing, actually. If my recollection is correct.