Saturday, 18 May 2013

Where it all began

This is pretty much where my interest in microcontroller, computer interfacing and all the rest of it really began, way back in the Spring of 1989.  I had been interested in electronics since I built my first radio when I was about 13 or 14 in the late 1970s and I'd learnt to program on a borrowed ZX80 a couple of years after that, but this was my first proper interfacing project.

I was living in Wembley at the time, an impoverished student teacher and one of my tutors suggested a cheap robotics project might be interesting as a way into Logo and this was the result.  I used to make weekly trips on the Tube up to the Maplins in Edgeware to buy whatever I could afford.  I already had the Spectrum and brought that over on the 'plane from Belfast at some point.  The 'monitor' is a Sinclair Microvision, no word of a lie.  I used a 12-inch portable for the programming, but designed a user interface with huge characters, 4 times the height of the normal ones so they could be read on the tiny Microvision screen.

The Lego 'whirly' robot had 2 motors and eventually had feedback from DIY microswitches so it could tell pretty accurately where it was.  It could be steered using the joystick and the program learnt moves that could be played back.  Interfacing was via an 'IN31' board (which I think was the way the Kempston joystick interface worked) with extra TTL logic to give 8 input addresses and 8 output addresses.  You can just see the little blue relays which switched the motors on and off and backwards and forwards.

The inspiration was this book, which I found in a primary school library and borrowed for a year, but I did take it back and eventually got my own copy about 10 years ago which I still have.

And here's the scene of the crime, the upstairs flat in Metroland (Chalkhill Road, Wembley) that I was living in at the time.

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