'My favorite platform' debate (was: Rack Mount Servers)
Jerry Feldman
gaf at blu.org
Tue Aug 13 10:26:35 EDT 2002
While my first computer was an IBM 7044 mainframe (punch card input only).
after a few years in the Army playing knob dicker to grunts, I worked at
Burger King Corporation. The Burger King POS was a 4K PDP8-E. No disk, no
tape.
The modem was a Novation modem card. We did the internal timing for 1200
baud (at that time, baud was equivalent to bps). We developed our own
protocol. The PDP8 was a 12 bit machine with data stored mainly as 12 or 24
bit integers. We polled each store nightly from Miami. We had to write the
code to strike the hammers on the drum for the printers. Since the PDP8s
were core memory, power fail was:
save all registers (the 8 only had one accumulator and a 1 bit link). That
4K system could do quite a bit maintaining inventory, cash, hourly sales
and a few other functions.
The keyboard was not ASCII. We had to read the row and the column to figure
out what key was pressed.
The code we wrote was extremely tight. The comm routine was vectored so we
could transfer a new version. The steps we used were to first transfer a
new comm routine to the scratchpad area. When complete, then update the
vectors pointing to the comm and scratchpad. Once the new comm routine was
running, we could transfer a new program. Normally all our data transfers
used physical addresses, which were not very portable.
On 13 Aug 2002 at 10:03, Brian B. Riley (N1BQ) ListAcc wrote:
> ... hell ... as long as we are reminiscing about the good old days.
--
Jerry Feldman <gaf at blu.org>
Associate Director
Boston Linux and Unix user group
http://www.blu.org PGP key id:C5061EA9
PGP Key fingerprint:053C 73EC 3AC1 5C44 3E14 9245 FB00 3ED5 C506 1EA9
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