Subject: RE: difference between LSI-11 CPU's M7264 and M7270
From: "Gooijen, Henk" <GOOI at oce.nl>
Date: Tue, 27 Sep 2005 17:18:41 +0200
To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk
at classiccmp.org>
Thanks, Frank and Allison.
I guess, now is a good moment to start reading the LSI-11 handbook
and to look out for a bootstrap kind of module ! Is there a specific
module to look for, or are there several possibilities? Remember,
this system only has 4 slots (almost 2 occupied), and I want to add
at least modules to get some parallel I/O (TTL) lines, and to boot
the system from (Pete Collum's RXV11) ...
Rev11 is available most commonly with RXV11/21 floppy boot and others
that exist for paper tape boot and maybe other disks.
It's not essential as a boot prom as most boots are small and uODT
can be used to hand load them.
The idea that I have for this system is the following.
I want to use a small 486 system as terminal and mass storage.
The parallel I/O will interface to a filter-based RTTY demodulator.
Software (to be written) will turn this setup to a telex reception
station (transmitting RTTY will follow!) I know that many programs
already exist for this (not on PDP-11), but I want to learn MACRO-11
and learning a language goes best if you have an application idea.
I expect it will not be difficult, after I learned the way MACRO-11
wants its assembly text, because it looks quite like M68000 mnemonics.
That will probably cause some pitfalls, but I must look up all the
PDP-11 mnemonics in the beginning anyway.
RTTY can also be done with a serial line card. The only thing
is baud rate setting (external switch) for multiple rates. If you
can find a DLV11J (thats 4 serial ports on one dual width card) or
MXV11 (2 serial ports +ram +rom) that would save slots.
One thought, a M7270(KD-11F) OR M8186(KDF-11A) and M8047(mxv11)
will be a complete system on two dual width cards (cpu, 2 serial,
ram and eprom). It will need about 4A of +5 and under 1A of +12 power.
An alternate CPU is the falcon card M8063 (Kxt11 SBC11/21) which
also has ram, Eprom, two serial lines and parallel io with a Qbus
interface. Common as can be but rarely seen as they are often
embedded in larger systems (like a NC milling machine).
The above was typical of how LSI-11 series componenets were used in
embedded systems.
The instruction set for PDP11 is more regular than 68k and very
orthoginal CISC. Do read the various dec PDP-11 programming books
as it's a flexible machine and relocatable code is easy to do.
Allison