Antique computers (was Re: LILO and Zone Alarm)

[Harold Hallikainen]

The first community college class I taught was assembly language
programming on the PDP-8. We used the Teletype ASR-33 and punched paper
tape. You'd use the toggle switches to load in one loader (the RIM loader,
maybe), then read a paper tape that would load another loader (the BIN
loader, I think). From there, you could load your editor and assembler
from paper tape. Once you edited your source (on the Teletype), you'd
generate a punched tape. Start the assembler and feed the source tape
through twice (two pass assembler). Out would come an object tape. Start
up the BIN loader again to read the object tape into core. Then debug with
the front panel switches and lights.

Remember how the PDP-8 did subroutines without a stack? The return address
was stored in the "first" location of the subroutine. A return was then an
indirect jump back to the first location, which would take you back to the
one that called it. No recursion here!

Remember the assembly instruction for two's complement (or negate)? It was
CIA for Complement and Increment Accumulator. I used this just a month ago
in teaching a logic circuits class on how two's complement arithmetic
works.

Harold


> On Wed, May 26, 2004 at 10:51:01AM -0700, Rick Stevens wrote:

> Gadzooks!  In 1970, I did my (Univ. of Okla.) senior project on a
> PDP-8L.  Rocker switches and TeleType ASR-33 to load the boot loader,
> then it would load the OS from a high-speed optical paper tape reader.
>
>> Ah, memories! ;-)
>
> Indeed.
>


-- 
FCC Rules Online at http://www.hallikainen.com