Jupiter Ace - Case Dimensions

Discussions about Sinclair ZX80 and ZX81 Hardware
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gammaray
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Jupiter Ace - Case Dimensions

Post by gammaray » Tue Jan 22, 2019 11:07 pm

Does anyone have hard dimensions for the Jupiter Ace case? Draft angles if possible. :?:

Thanks.
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: Jupiter Ace - Case Dimensions

Post by gammaray » Wed Jan 23, 2019 3:20 am

Overall is 215 mm x 190 mm 30 mm which is a good start for an envelope.
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

McKlaud
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Re: Jupiter Ace - Case Dimensions

Post by McKlaud » Wed Jan 23, 2019 10:46 pm

I will have an access to the Juppie in a few weeks. I will try to take some measurements and draw a sketch.
Claudius
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gammaray
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Re: Jupiter Ace - Case Dimensions

Post by gammaray » Wed Jan 23, 2019 11:22 pm

I think there are two different cases. The vacuum case would be good. I guess the injection molded case would be good too!

http://www.jupiter-ace.co.uk

I was planning on making a PCB design (in the future) to distribute that would fit the new Spectrum cases....

Back to my unfinished projects list.... :( :oops: :cry: :oops:
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: Jupiter Ace - Case Dimensions

Post by 1024MAK » Thu Jan 24, 2019 12:20 am

Would your new PCB design to fit in a ZX Spectrum case (assuming it gets finished) be using the same memory chips as the original. Or are you intending to use more modern CMOS chips, such as 74HCTxxx logic, CMOS SRAM, CMOS 27C256 EPROMs (or similar) etc.?

Mark

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gammaray
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Re: Jupiter Ace - Case Dimensions

Post by gammaray » Thu Jan 24, 2019 1:58 am

I am not currently smart enough to use new components or redesign. The idea is to repackage the original board components on new PCB to fit and use KDLX keyboard for the Spectrum case. Big project...

Blank rubber membranes to put on custom decals are needed to get proper layout.
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: Jupiter Ace - Case Dimensions

Post by gammaray » Thu Jan 24, 2019 11:34 pm

Maybe I will have you use new replacements of components. I was looking elsewhere and these kits seem to do that... I don't have an original and they too pricey.
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: Jupiter Ace - Case Dimensions

Post by 1024MAK » Fri Jan 25, 2019 1:38 am

Well, all I was thinking is that with modern memory chips (RAM and EPROM), all you have to normally do is to connect the extra (unused) address pins to 0V/GND. They then should be operationally equivalent to the older chips used in the original design. The modern memory chips are still in production, so sourcing them should not be too hard. Whereas the memory chips used in the original Jupiter Ace are rather hard to find now.

There is a slight niggle. To reduce the chip count, if using higher capacity modern chips, with a slight change to the memory decoding circuit, you need less memory chips. I can help with this if you want.

Most (but maybe not all, I have not checked) of the 74LXxxx chips should be available as 74HCTxxx types. These should in most cases be operational equivalent in terms of logic function(s).

All of the above changes will also reduce the heat given off, and hence reduce the power consumption. If a modern CMOS Z80 CPU is used (they are still made), this will further reduce the power consumption :D

Any programs will be completely unaware of the different circuitry (apart from one very minor difference between an NMOS and a CMOS CPU). And unless a programmer opens the case, he/she would also not know.

I don’t have an original Jupiter Ace myself, but I do have one of the recreated kits (built and working) that were sold on eBay some years ago.

Mark

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1024MAK
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Re: Jupiter Ace - Case Dimensions

Post by 1024MAK » Fri Jan 25, 2019 2:03 am

A single 27C256 EPROM can replace the two older EPROM chips (only the first 8k bytes used in the 27C256 EPROM chip).

A single modern SRAM can replace the two 2114 SRAM chips (main RAM).
Two further modern SRAM chips can replace four of the 2114 SRAM chips (video and character RAM).

That reduces the memory chips from 8 to 4 :D

Mark

McKlaud
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Re: Jupiter Ace - Case Dimensions

Post by McKlaud » Fri Jan 25, 2019 2:15 am

28c64 would better option for ROM. 6116 chips in narrow packages are still in production.

6.5MHz crystal oscillator could be replaced with 13MHz one with a simple mod to the circuit.

And so on ;)
Claudius
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