On Mon, 30 Jul 2018 10:13:44 +0100
charles wrote:
In article ,
wrote:
On Sun, 29 Jul 2018 16:39:18 +0100
TMS320 wrote:
On 29/07/18 09:16, wrote:
I assumed ABS systems had always been microcontroller controlled,
didn't realise there were analogue versions. Interesting to know.

The electronics industry didn't make a quantum leap from analogue to
microcontroller. There was an intervening period with boards full of
logic chips, plenty of which would have been part analogue, such as
monostables. Then, not all of it could instantly be mopped up by micros.

I suppose in theory there's little you can do in software that you
couldn't hardwire in TTL,

The original Ceefax decoders were in 2 x 3U racks - all TTL. It all got
into one dedicated chip/

Was that chip stil hard wired or did it use software by then? The problem
with hardwiring is if you find a bug its a LOT harder and more expensive to
fix (if its even possible without a redesign) than just updating the ROM code
in subseqent batches.