B
BillW50
The BBC Master computer (6502-based, or it might have been 6512) had the
ability to use a "second processor"; IIRR more than one type was
available, but certainly 80186 was one of them. It sort of - IIRR - used
the existing computer as a sort of terminal to the new one. The 80186
came with something - I think it was a version of DR DOS - which created
a (somewhat crippled, as it loaded from floppies) decidedly bizarre sort
of PC.
Wow that is very interesting. I know tons about the MOS 6502 and 8510,
but absolutely nothing about the 6512. And how did that second processor
work?
For example the Commodore 128 used MOS 8510 and a Z80 soldered right on
the motherboard. But the Z80 did not do anything as far as I know until
you ran CP/M. Then the 8510 handled the hardware while the Z80 handled
the OS and the applications.
Everything sounds wonderful and all. But there was one huge
disadvantage. And I think this applies to all dual processors back then.
As they shared the same address and data lines. Thus one had to be put
to sleep before the other one woke up and the reverse is true too. So
all of this waking and putting to sleep slowed things down more than
just using one processor alone.
Although the huge advantage was that it was more compatible with far
more things than one processor alone. The Commodore 128 for example when
it first came out bragged that it could run more software than anything
before it. And I think that was true for a few years after. But it
wasn't MS-DOS compatible and MS-DOS applications was growing far faster
and it had overtaken even the C128 a bit later.
So was this the same with the BBC Master computer?