On 03-Nov-05 James Knott wrote:
Anyone here remember 8" floppies? Hard sectors? CP/M?
Does an HP-85 programmable calculator count?
That was my first personally owned programmable machine.
I even embarked on a (mental) project, to design a frame to
fit it into, attached to a paper-tape reader where a pattern
of holes in the tape would operate on of a set of push-rods
on the frame so as to press one of the HP-85's buttons
(I wanted to be able to store my sometimes complicated
prgrams, you see, rather than have to key them in by hand
every time). However, this ran into design overload when I
realised that, to eliminate the overhead of punching the
tape by hand, consulting a list of hole-patterns, I needed
the inverse mechanism: A maquette of the HP-85 keyboard
panel linked to a tape-punch.
Anyway, this became obsolete when (a) the HP-85 was stolen,
(b) it was then replaced by the new TI-59 calculator, which
stored its prgrams (and data) on little magnetic cards.
But my first *real* personal computer was a Sharp MZ-80B.
I don't know if this is what Dana Laude was referring to,
but it was certainly built like a tank! Twin 5.25in floppies,
64K RAM, and you could get CP/M for it (which I did), and an
optional 64K extra in two 32K pages for graphics RAM
(and if you were OK with Z80 assembler you could borrow
this as extra program RAM since when in use it paged in
over the top 32K of main RAM).
Anyway, the great thing here was that at about the same time
(very early 80s) there was Aztech C -- a very capable
implementation of C for CP/M.
And so it goes ... I still have that machine, along with
the 300-baud Andersen-Jacobsen acoustic modem (two rubber
cups) I used to use with it.
Mind you, if we're realy going back, I remember doing a
summer vac job as a student in 1957, where the task I was
given something to do with was programming a timing loop
for one of the very early IBM mainframes. The issue was
that -- apart from the enormous phalanx of massive mag tape
units along one wall, the machine relied on a magnetic
drum for more rapid access of data and program. Because
the drum spun faster than the data could be read continuously,
you had to read a bit and then wait until the next bit came
round on the next turn. Meanwhile you could so something else
-- but you had to be ready to read the sequel to the first bit
when it came round. Hence the timing loop ...
That was a long time ago.
Anyone on this list worked on ENIAC?
Cheers,
Ted.
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E-Mail: (Ted Harding)