Sinclair ZX80 / ZX81 / Z88 Forums

Online sources have failed me.
I'd like to grab a copy of the Downey / Rindsburgh book Timex Sinclair interfacing if anyone can help me out.

Check it on Ebay https://www.ebay.ca/itm/155118322890
Good luck

Thanks, unfortunately to the UK that's £70
I don't mind buying it but not at that price

A viable substitute might be most anything on Z80 interfacing. The expansion connection brings out the needed signals. What sort of thing have you in mind ?

Initially I'm looking at simply being able to interact with some simple external items such as switches, leds and potentiometers although that may progress if I get the hang of it
Initially using basic as I'm still only just starting out with machine code which I understand limits me to a memory mapped version until I've got to grips with that.

I've got a couple of possible interface options to build. I've already got the easy add on projects book by Bishop and the explorers guide to the zx81 which has an option in there. I've also got a couple of different magazine article versions and the ins and outs of the zx81 book but this book was recommended as being quite helpful.

I fully accept I can already do all of this much more easily with my arduino uno but I'm trying, 40 years later, to blow my 1981 mind

Fun stuff. Yea easier to do with a Uno but that's not the point. Not gonna be easy to learn machine language on a Uno. Maybe look into using an 8255 PPI chip to make things a little easier. Great part, easy to use, can eliminate a lot of 'glue' chips & make building up a series of test circuits easier.

There are a number of I/O interface details on these forums…

One using only 74LSxxx TTL logic chips, plus a Maplin design using a 8255. Details of which are in the relevant Maplin magazine / project book. A bunch of which are available online.

Mark

The one I'm starting work on first is the one that seems the easiest for me to understand from both an electrical and programmable perspective which will be a full ttl memory mapped version. It'll have 8 outputs and eight inputs.
We'll see how I go from there.