TAZMANIAC

Any discussions related to the creation of new hardware or software for the ZX80 or ZX81
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gammaray
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Re: TAZMANIAC

Post by gammaray » Mon Dec 04, 2017 4:39 pm

That is true.
Once you have ZXPand with RAM built in the case there is no way to add UDG externaly.
That speaks against internal ZXPand (or add internal UDG as well)
Kind regards Paul
Now I may be really running out of room! Must give pause...
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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siggi
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Re: TAZMANIAC

Post by siggi » Mon Dec 04, 2017 9:43 pm

If memory (ZXPand) is inside the case: don't forget to allow disabling that internal memory from outside (via signal /RAMCS). Otherwise it would not be possible to add external ram, e.g. the Chroma81 interface ...

Siggi
My ZX81 web-server: online since 2007
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gammaray
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Re: TAZMANIAC

Post by gammaray » Fri Feb 16, 2018 2:51 am

Good point. I am waiting on Rev 0 of the board for prototyping, perfboard style, of various potential configurations of the kit.

I can see them in my mind in the cargo-hold of a slow moving freighter across the Pacific getting lost in the Japanese Dragon's Triangle comparable to America's Bermuda Triangle...

Gonna need a most awesome torch to get modulator off mainboard... What would that look like?
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: TAZMANIAC

Post by gammaray » Sat Feb 24, 2018 11:54 pm

Is that saw too big for this project? See any problem using it to get off RF modulator?
IMG_20180224_131853.jpg
Last edited by gammaray on Sun Feb 25, 2018 12:11 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: TAZMANIAC

Post by gammaray » Sat Feb 24, 2018 11:56 pm

STEP 1:
IMG_20180224_152847.jpg
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: TAZMANIAC

Post by gammaray » Mon Feb 26, 2018 4:56 am

Of course it does not look like the old components for ear and mic survive removal and the capacitors need perfunctory replacement. The parts list performed by others are much appreciated.

Still don't know if a chisel tip will provide enough conduction path for iron to remove modulator.

Adding to my list of required parts...
IMG_20180225_183213.jpg
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: TAZMANIAC

Post by gammaray » Tue Feb 27, 2018 2:06 am

Spectrum case geometries different from TS 1500? Looking for parts... it was here somewhere!

Otherwise finding the proverbial Pandora's box.
IMG_20180226_102138.jpg
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: TAZMANIAC

Post by gammaray » Tue Feb 27, 2018 2:15 am

Stripped modulator, grounding strap

Keyboard attached using adaptation of FPC? wire. Replaced membrane connectors with SIP and moved (replaced) membrane connectors. Swapped D3 and D4.

ROM too tall...need to remove DIP socket or move ROM elsewhere. Other ideas abound.

ZX81 and Spectrum have different board elevations. Gonna end up modifying case openings for access.

More to do...
IMG_20180226_185740.jpg
Last edited by gammaray on Tue Feb 27, 2018 12:12 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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mrtinb
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Re: TAZMANIAC

Post by mrtinb » Tue Feb 27, 2018 9:46 am

Very nice progress.
Martin
ZX81, Lambda 8300, Commodore 64, Mac G4 Cube

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