TI99/4A KEYBOARD ADAPTATION

Discussions about Sinclair ZX80 and ZX81 Hardware
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gammaray
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Re: TI99/4A KEYBOARD ADAPTATION

Post by gammaray »

P5 AND 2Y0 ARE NOT USED

This is what I came up with. Did you? Combined with the other table is fully decoded.
TI PINOUT.jpg
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I have not found any logic errors on your board yet but still not done...
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM
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gammaray
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Re: TI99/4A KEYBOARD ADAPTATION

Post by gammaray »

Check to see if you have 2Y1 shorted with 2Y2 at "<". Following the traces it looks like it. I cant see diagram well enough to be sure. Let me know.

UPDATE: I see the "2y2" trace cut in photo from a different angle. Still looking.


One thing one hasve to decide first I guess is do you want all the keys to stay in position like normal typewriter layout.
The second is whether you want to use the "extended keys" available or have a ZX keyboard layout.

I chose to leave keys in place, but moving the caps is also a way.viewtopic.php?f=7&t=2771#p29847

Charles :)
Last edited by gammaray on Sat Mar 10, 2018 5:12 am, edited 1 time in total.
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM
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gammaray
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Re: TI99/4A KEYBOARD ADAPTATION

Post by gammaray »

Do we need a driver board to repeat(amplify) the signals?
https://sinclairzxworld.com/viewtopic. ... oard#p2046
Last edited by gammaray on Tue Feb 20, 2018 6:59 pm, edited 1 time in total.
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM
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gammaray
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Re: TI99/4A KEYBOARD ADAPTATION

Post by gammaray »

TIKEY WIRE CROSSOVER_2018-02-20_11-55-55.png
is this correct?
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM
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1024MAK
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Re: TI99/4A KEYBOARD ADAPTATION

Post by 1024MAK »

gammaray wrote: Tue Feb 20, 2018 5:48 pm Do we need a driver board to repeat(amplify) the signals?
https://sinclairzxworld.com/viewtopic. ... oard#p2046
Not if the wiring is kept as short as possible.

If you do want longer wiring, or want to use a multicore cable, then it's the address lines that need buffering. On the Harlequin, transistors are used.

Mark
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gammaray
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Re: TI99/4A KEYBOARD ADAPTATION

Post by gammaray »

Danmoore used 12" ribbon! He is pushing the envelope. Not really, I would expect 6' to be a problem. I could test it...
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM
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gammaray
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Re: TI99/4A KEYBOARD ADAPTATION

Post by gammaray »

D3 AND D4 should be crossed for Speccy operation so DPDT switch should work.
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM
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gammaray
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Re: TI99/4A KEYBOARD ADAPTATION

Post by gammaray »

WIREDUP.png
WIREDUP.png (8.38 KiB) Viewed 3837 times
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM
soviet9922
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Re: TI99/4A KEYBOARD ADAPTATION

Post by soviet9922 »

Thanks for the diagrams :) this last one is really help full going to give it a shot tonight.
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gammaray
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Re: TI99/4A KEYBOARD ADAPTATION

Post by gammaray »

I am making a PCB to be able to connect ZX81 keyboard matrix directly into keyboard in the TI99 case and mount main board with a modified TAZ project... not there yet. Need to check pinout again before I order. TAZ 1.0 being layed out.

(Project still requires trace modification cuts to your specification, but eliminates another cable)
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM
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