On Wed, 24 Dec 2003 00:38:50 +1300, Russell McMahon wrote:

>> A hand assembled program entered in binary dip switches enabled a hex keypad.
>
> Hex keypad!
> You had a hex keypad ! ????????????
>
> When I was a boy we only had binary switches for all input (address and
> data).

I had the luxury of a "terminal" device - a keyboard which sent ASCII into a serial port, and a 20 x 32 VDU
(monochrome, of course).  But I only had a 1k "Monitor" program in firmware (called MinMon, if I remember
rightly) so I had to write my programs on coding sheets, hand-assemble them and then type in the hex, but
using a QWERTY keyboard!  I never did get the Maze Mouse software finished, and sadly by the time of the
competition it would only stumble around the maze without knowing where it was.  This was using a Z80
(2.5HMHz) with 2k of RAM (in 2114s) and a ROM-like device that was actually low-power RAM with a lithium
battery to keep the contents alive, all potted in some black gunge with 24-pins sticking out of the bottom,
and a "write enable" wire.  They reckoned the battery would hold the data for 10 years, which seemed like a
lot... 22 years ago  :-)

I still have it all somewhere...

>     Russell "uphill to school both ways, in the snow,
>         without shoes, at the bottom of a lake in a
>             cardboard box*" McMahon

Cardboard Box?  You had Cardboard Box???

You tell that to kids of today - they don't believe you!

 :-)

Cheers,

Howard Winter
 St.Albans, England

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