'Home' computer: Definition

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Mon Jun 30 17:51:37 1997

In message <33B75A67.2AE4_at_ndirect.co.uk> classiccmp_at_u.washington.edu writes:
> Brett wrote:
> >
> > On Sun, 29 Jun 1997, e.tedeschi wrote:
> > > There are computers that you could not possibly USE but they are
> > > important for what they meant (and mean today) in short for their
> > > "heritage". Without them you could not have used (and use) the ones you
> > > are using today.

I assume the following is one of the computers you claim can't possibly be
used today...

> How about the Science of Cambridge (Sinclair) MK XIV ? It had 256 bytes

You mean an MK-14. I've never seen it printed in roman numerals (I have the
machine, user manual, a couple of 3rd party books, the adverts, etc, etc,etc
It was my first computer).

> (NOT Kb, BYTES) of RAM memory, LED display, not modulator and no way of
> storing programs (you could add these at a later stage as accessories).

Perhaps you could explain _why_ I can't use one today. I've written many,
many embedded control programs (monitor some inputs, update state variables,
toggle outputs, etc) that would _trivially_ fit into 256 bytes of SC/MP code.
If I add the optional INS8154 RAM/IO chip I have another 128 bytes of RAM and
16 bidirectional I/O lines. I can also add another 256 bytes by raiding my
junk box for some 2111's.

I can think of a few dozen applications that I could use that for. A trivial
one is an I2C chip tester - replace the monitor ROMs with ones burnt to contain
the correct code (avoids using the cassette interface option...), and have
said code read I2C addresses/data from the hex keypad and bit-bang the I2C
protocol on a couple of the 8154 lines. Or, how about a Centronics printer
tester (emulate the centronics port on the 8154, make it print the classic
scrolling ASCII text). Or a programmable pulse generator for digital IC
testing. Or a hundred-and-one other applications.

Yes, I can do any of those with a PC or many, many other machines. But the MK14
is small and portable. It doesn't need a monitor. It will start the program
instantly at switch-on. It is still useful today.

> enrico


Received on Mon Jun 30 1997 - 17:51:37 BST

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