The very first personal computers - How many are left?

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Thu Apr 10 17:46:01 2003

> On Thu, 10 Apr 2003, Tony Duell wrote:
>
> > If the IBM 5100 is classed as an 'early personal computer', why isn't
> > the HP9830 also included? The 9830 came out in 1973 (I think, maybe
> > 1974). It had a cut-down BASIC in ROM (no string variables, for one
> > thing, but it _is_ BASIC) which could be extended by plug-in ROM modules
> > (Matix Operations, String Variables, Extended I/O, Plotter, Terminal
> > Emulator, etc all exist). It could take up to 16K bytes of RAM, had a
> > full-size QWERTY keybard and a 1-line 32 character display. Oh, and 4
> > I/O slots.
> >
> > Is the only reason this is not classed as an 'early personal computer'
> > the fact that it says '9830 Calculator' on the nameplate?
>
> Was it aimed or marketed at the general computing market? Could it be
> easily used as a general-purpose computer?

It _is_ a general-purpose computer. Turn it on, you get a prompt. Start
typing in BASIC program lines. Type RUN (or press the RUN key) to execute
your program. The only calculator feature is that you cna type in an
expression and press EXECUTE (rather than END LINE) to evaluate it.

There's also a built-in digital cassette drive for saving programs and
data. Up to 10 more such drives can be added externally. There's also an
option that I've never seen that allows up to 4 9830s to share a rack of
demountable hard disks (I think RK05-like packs).

If you insist that a 'computer' must be able to process strings as well
as numbers then you'd have to add the String Variable ROM. This is an
option, but it's not particularly rare.

If you insist that a 'computer' must have I/O facilities, well, the 9830
has a built-in interface for the 9866 printer. This is a 7 bit (!)
parallel port, a bit like Centronics. There are also 4 slots for HP
interfaces. There are built-in software drivers for a printer interface
and also for a special HP card reader or paper tape reader that simulates
a keyboard. For other I/O operations you need the Extended I/O ROM. There
were 8 bit parallel, BCD, RS232 and HPIB interfaces at least.

These ROMs come in 2 versions. Either as a PCB that fits inside the
machine (there are 3 such slots) which had to be installed by HP
engineers [1], or as a user-installable cartridge that fits into one of 5
slots in a little cage behind a door on the left side of the machine.
Most ROMs came in both versions, some came as a cartridge only.

[1] No idea why. The procedure for installing such a ROM is : Remove top
cover. Remove 1 more screw and the PCB hold-down clamps. Put the ROM PCB
in the slot, matching up the handle colours with the guides (I don't
think it will fit backwards anyway). Put the machine back together.

-tony
Received on Thu Apr 10 2003 - 17:46:01 BST