Jupiter ACE (again)

[McKlaud]

Hi all,

I was looking for a nice example of Jupiter ACE but prices made me thinking about making the computer by myself. I did my homework and looked at Grant's website and a few others. After a few weeks of thinking I redrawn the PCB from available photos and others works, made minor modifications around ROM chips (2732 type instead of 2532 units) and ordered a very small batch of boards. Last weekend I finished the board and sucessfully powered it up.

Making the long story short, please have a look there: Jupiter ACE Recreated

Still some issues with sync on my LCD TV but generally I am happy with the outcome.

[Paul]

Hey Claud
That looks very good.
Do you have a board for me?
Which program did you use?
I would also be interested in a version that uses the micro switches as in Pokémons keyboard replacements e.g. Kldx48 for Spectrum 48k.
Kind regards Paul

[McKlaud]

Hi Paul,

Thanks a lot. I made a very small batch of these boards, but I would be able to find one for you. To be honest the PCBs are not perfect and 3 traces have to be cut in keyboard area, where I made mistakes. Bear in mind that the idea was to keep this board as close as possible to the original one. So the PCB is as it is. Yes, I am going to make this board fully operational, test it a bit more, correct all mistakes and possibly order very small batch (5 to 10 units) of the final one. If you are still interested in the board from this batch I've got, please drop me a PM.

I have also been thinking about changes to the keyboard and use small tactical switches (SMD type) there and this is feasible. I would do so, but in the different board format and using newer chips than 2114 or 2732 and adding a emitter follower to the video output. In my mind the updated board would be in the Zeddy's format with ZX81 membrane + Jupiter ACE Keyboard overlay.

Regarding software that I used, it was Robot Room Copper Connection.

[Lardo Boffin]

Looks impressive. Are you going to be selling kits?

[brozier]

Wow,

That looks really good well done

I always wanted a Jupiter Ace, certainly be up for a kit or PCB purchase if you do another run of them.

Julia

[Paul]

In my mind the updated board would be in the Zeddy's format with ZX81 membrane + Jupiter ACE Keyboard overlay.

Hi Claudius
I was thinking about using a 48k rubber mat in order to get the rubber feeling of the original,
Maybe cut off the keyboard part and use that membrane replacement from Pokémon for 48k spectrum.

[1024MAK]

Still some issues with sync on my LCD TV but generally I am happy with the outcome.

Maybe this thread will help

Mark

[McKlaud]

Lardo Boffin & brozier

Thanks a lot. There is a small chance that I will make another limited batch of the PCBs and PCBs only. But first things first and I am going to do more tests with my boards. To be honest I've never planed that this PCB would be available in large numbers.

1024MAK

Thanks a lot. I did some tests today and the image from the modulator on another LCD TV was clear and crisp, no flickering at all. I can blame my picky modern TV for all these issues. Anyway, you did hell a lot improvements to the boards. Well done, but they are not fully up to my taste, because I would like to keep my board as close as possible to the original one. Definitely they are going to be very useful for any redesigned boards.

[McKlaud]

The video output signal on the modulator input below. In my mind it looks fine but my silly TV set things otherwise and flickers.

[Lardo Boffin]

I found with the ZX81 and a ZX8-CCB there is variance in results from one TV to the next.
I have a normal resolution old LCD TV that easily produces a perfect picture, an old glass screen TV that normally does, a 37” Sony Bravia that is either perfect or awful and a small LG which is extremely picky.
A picture that is perfect on the other three may be flickery and often has colours showing on the LG. Some zeddys I have never been able to get right on this telly.

You can’t please all of the TVs all of the time!