New project: An ACT Apricot F1 "barn find"

[rubber_jonnie]

I'm sure you've already seen this, but thought I'd add it anyway: http://www.computinghistory.org.uk/det/2729/Apricot-F1/

I find it slightly odd that they went for the IR KBD but since reading some stuff on it it seems it was partly intended for home use with a TV connection and the keyboard makes sense if you're sat on a sofa.

[stephen_usher]

Well, it's not really a home system. There was a modulator add-on for the machine but it wasn't standard. You have the normal Apricot TTL RGBI 9 pin colour output (H-sync/V-sync) and mono composite video otherwise. It is rather more stylish that the Xi/PC though.

Given how many people like wireless keyboards and mice these days I can see why the idea of a wireless keyboard would have been innovative and desired but the IR technology just wasn't up to the task. Only now with 2.4GHz radio and the processing power for the protocols required has allowed this to become reliable.

[rubber_jonnie]

Well, it's not really a home system. There was a modulator add-on for the machine but it wasn't standard. You have the normal Apricot TTL RGBI 9 pin colour output (H-sync/V-sync) and mono composite video otherwise. It is rather more stylish that the Xi/PC though.

Given how many people like wireless keyboards and mice these days I can see why the idea of a wireless keyboard would have been innovative and desired but the IR technology just wasn't up to the task. Only now with 2.4GHz radio and the processing power for the protocols required has allowed this to become reliable.

Yes, I agree, I recall a lot of stuff trying infra-red back in the day, and none of it being particularly successful. Sounds like fun and games building the IR adapter. Out of curiosity, is it bi-directional?

[stephen_usher]

No, purely unidirectional.

I've attached the schematic diagrams for the relevant part of the machine, i.e. the keyboard itelf, the IR receiver circuit and the interface with the Z80-SIO.

Note that the "2.5MHz" input to the 556 timer is actually 2.24MHz in reality.

f1-keyboard-decode.jpg (207.15 KiB) Viewed 2441 times

f1-keyboard-circuit.jpg (242.25 KiB) Viewed 2441 times

f1-ir-receiver.jpg (163.17 KiB) Viewed 2441 times

[rubber_jonnie]

I see the KBD uses a microprocessor (I guess microcontroller is closer to the truth), shame you can't just recreate the original.

Interesting stuff!

[stephen_usher]

I see the KBD uses a microprocessor (I guess microcontroller is closer to the truth), shame you can't just recreate the original.

Interesting stuff!

Yeah. Unfortunately it has an internal mask ROM and no information about the code.

[rubber_jonnie]

I see the KBD uses a microprocessor (I guess microcontroller is closer to the truth), shame you can't just recreate the original.

Interesting stuff!

Yeah. Unfortunately it has an internal mask ROM and no information about the code.

Shame the code hasn't been preserved somewhere. Good luck with your IR endeavours, it's very interesting as although I have a reasonable understanding of what components do and how computers function, I just don't have the skills to design something like that, I wouldn't know where to start!! Looking forward to seeing the results in action.

[stephen_usher]

OK. I *may* not need to do this. I've found an Apricot F2 for sale on Facebook Marketplace for £30 and I'm negociating to buy it... and it comes with a keyboard!

[stephen_usher]

Well, the F2 with keyboard arrived today, amazingly.

What was more amazing was how poorly it was packaged... Thrown straight into a flimsy box with no padding with a load of cables and then sent via ParcelForce!

It's going to be another case rebuild.

[rubber_jonnie]

Well, the F2 with keyboard arrived today, amazingly.

What was more amazing was how poorly it was packaged... Thrown straight into a flimsy box with no padding with a load of cables and then sent via ParcelForce!

It's going to be another case rebuild.

Good find, shame the seller couldn't be bothered to do a proper packing job

Is the keyboard identical from an IR perspective?