On 03/08/14 11:10, Michael Black wrote:
The circuits of such devices were often very cleverly designed, re-using
many components between receive and transmit (using a multipole switch).

They were really complicated switches, for the sake of a few transistors.

Yep. This one I gutted, I recall de-soldering the switch and then
reverse-engineering the pinout so I could replace it with a relay, which
I did. A 4-pole double-throw relay IIRC.

I had some hair-brained idea (this was when I was in primary school) to
hook the thing up to the PC-speaker output of the computer (since I knew
how to make tones) and then use some circuit interfaced to the game port
(since I knew how to read the switches on those) and try to send data
using AFSK.

Exactly what data rate I'd achieve, given the whole lot would be
implemented in QBasic I have no idea. I doubt it'd outpace PSK31.

Not that I knew what AFSK was back then. Or that to do what I wanted to
do, I really should have a radio license which I didn't back then.