Niklas Jansson

BBC Micro Concept

Added 2024-03-17 12:13:47 +0000 UTC

I made another wacky keyboard. Number and currency stuff for completely left-handed entry. Experimental placement of BS, DEL and arrows on the spacebar row rather than the usual modifier keys. I put the more commonly used characters as primary (parenthesis > brackets). The Beeb had a clear plastic cover which could hold function key row papers (here for Elite). Love that dotty owl logo. Reminds me of the dotty "It's a Sony" one.

Interestingly the system's joystick port had two buttons and four analog channels (on a single connector). Analog was a bit tricky to implement on older hardware. Even on modern microcontrollers there's usually only one measurement thingy which is then redirected to the various analog pins to take voltage measurements. It seems on the Beeb the poll rate is practically 40ms or 25 times per second. Probably sufficient for games since they rarely ran at 50Hz. I don't think mice and joypads were at all common back in the early '80s for these machines (as many were found in British schools).

One might be able to implement a mouse as an analog device, but it would require a high frequency sensor to avoid lag, and three Digital to Analog Converters in the mouse (the benefit would be that analog joys would be pin compatible and usable directly as mice). Older mouse ports usually counted digital pulses instead, (4 quadratures), but didn't have pins for an additional mouse-wheel axis.

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Also, a Quick Galactic Gladiators (DOS) pixel-over. I'll see if I can do something more interesting later. Been wanting to draw the aliens and spaceport.