interesting find

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Fri Feb 7 17:54:00 2003

> And when nobody cared about the size, weight and power consumption
> of computers... ;-)
>
> > The HP 9100A/B calculators use a similar architecture, using
> > wire bobbins instead of rods, for a microsequence store.

The HP9100B was entirely discrete transistors [1], with normal R/W core
memory, the core-on-a-rope microcde store and inductively coupled PCB
tracks for the main program ROM.

The HP9810 which replaced it was built from TTL chips, with 256 nybble
PROMs for the microocde store (and the ALU, which was a couple of
programmed PROMs), 512 byte ROMs for the main program store, and 256 bit
DRAMs (1103s) for the R/W memory.

Admittedly the 9810 had space for an internal thermal printer, and it had
more user memory. But in the basic configuration it did less ('Math'
functions, like SIN, COS, TAN were on a plug-in ROM module on the 9810,
and bulit-in on the 9100). But the 9810 (the machine built with ICs) is
larger than the 9100.

[1] OK, there are 8 IC op-amps in the 9100B on the card reader PCB (read
amplifier and comparator for the 3 data tracks and the clock track). But
the machine will run without the card reader ;-)

-tony
Received on Fri Feb 07 2003 - 17:54:00 GMT