27 Nov
2020
27 Nov
'20
5 a.m.
On Thu, Nov 26, 2020 at 4:56 PM Will Senn <will.senn(a)gmail.com> wrote:
Hi All,
So, I'm about to get my very own Apple IIe and while it's an incredibly
versatile machine for assembly language and hardware hackery, I'm not aware
of any Unices that run on the machine, natively. Does anybody know of any
from back in the day?
It's got a 65c02 processor and somewhere around 128k of RAM, but it's also
pretty expandable w/7 slots and a huge amount of literature about how to do
stuff w/those slots.
My favorite 8-bit processor, maybe my favorite all around. So simple, one
accumulator and two index registers but it is only 64K of total address -
although with bank switching more memory could be added in 4K banks on a
number of Apple II's, but you have 16 address bits and worked a register
that switched in and out the 4K banks. and there is of course no protection
hardware nor the concept of user/kernel in the hardware. The size of the
Apple Floppy disk was rather small, and your need 3 to run things like the
UCSD Pascal system to have any experience other than constantly switching
disks.
There are a number of C compilers available but with its limited and fixed
stack (8 bits only), so it is difficult to run programs of any size (in any
language - automatics are often managed off the stack).
Running a full UNIX on it was not really possible although a few of the
Unix style utilities were moved to it and a number of simple monitors were
written that swapped programs in and out DOS style. At one time, I had a
fairly good version of the Bourne (V7) syntax shell we got running, but it
had to be swapped in and out slowly. That is; you run the shell, type a
command, when exec is done, the shell is tossed out and the new program
installed in memory.