Jupiter ACE Kit /sorry half off-topic! :)/

Any discussions related to the creation of new hardware or software for the ZX80 or ZX81
User avatar
Plamen Vaysilov
Posts: 5
Joined: Fri Dec 06, 2013 8:52 am
Contact:

Jupiter ACE Kit /sorry half off-topic! :)/

Post by Plamen Vaysilov »

I received PCB boards for Jupiter ACE kit project ,today will test if everything is as it should.

So coming soon with pictures and information ....
Attachments
Bottom.jpg
(161.37 KiB) Downloaded 1465 times
Top.jpg
(192.08 KiB) Downloaded 1465 times
"I really do like SOLDERING as my programming language." Bob Pease
XorA
Posts: 98
Joined: Thu May 10, 2012 9:14 am
Location: Glasgow, Scotland, UK
Contact:

Re: Jupiter ACE Kit /sorry half off-topic! :)/

Post by XorA »

Nice, one of those would look great beside (my currently unbuilt) zx80core :-D

G
User avatar
Plamen Vaysilov
Posts: 5
Joined: Fri Dec 06, 2013 8:52 am
Contact:

Re: Jupiter ACE Kit /sorry half off-topic! :)/

Post by Plamen Vaysilov »

Ready for test , kit coming soon.
Attachments
Top.jpg
Top.jpg (124.91 KiB) Viewed 71420 times
"I really do like SOLDERING as my programming language." Bob Pease
User avatar
Plamen Vaysilov
Posts: 5
Joined: Fri Dec 06, 2013 8:52 am
Contact:

Re: Jupiter ACE Kit /sorry half off-topic! :)/

Post by Plamen Vaysilov »

Is Working... !!!
Attachments
JAVorkingS.jpg
JAVorkingS.jpg (68.5 KiB) Viewed 71369 times
"I really do like SOLDERING as my programming language." Bob Pease
XorA
Posts: 98
Joined: Thu May 10, 2012 9:14 am
Location: Glasgow, Scotland, UK
Contact:

Re: Jupiter ACE Kit /sorry half off-topic! :)/

Post by XorA »

Nice, my first ever view of one working! Congrats!
sirmorris
Posts: 2811
Joined: Thu May 08, 2008 5:45 pm

Re: Jupiter ACE Kit /sorry half off-topic! :)/

Post by sirmorris »

Well done :D
User avatar
1024MAK
Posts: 5101
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Jupiter ACE Kit /sorry half off-topic! :)/

Post by 1024MAK »

:D Great work :D
Image . Image . Image . Image

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp

:!: Standby alert :!:
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :!:
Looking forward to summer later in the year.
Prime
Posts: 134
Joined: Thu Mar 24, 2011 3:02 am

Re: Jupiter ACE Kit /sorry half off-topic! :)/

Post by Prime »

Humm just bought one of them off Ebay,

Not managed to get it going (yet), there seems to be a problem with the clock oscillator, I have the 6.5MHz out of Q1 once I realized that the silk screen for the transistor was the wrong way round ! But it only produces a vmax of 1.6V, the signal out of pin 8 of IC23 (LS86) is only 3.6V As is the divided 3.25MHz fed through R7/C4 to Q2. Putting the scope on the base of Q2 I get absolutely nothing, which is why no Z80 clock.

Having checked with my Real Ace board, the signal levels out of the oscillator and out of the LS86 seem correct, so it seems the problem lies around Q2 somewhere.

I do get a display of random bitmaps (as the character RAMS are uninitialized at this point) though it is not syncing properly.

I do wonder why some of the R and C values have been changed from the original circuit ? Also Q2 is a 2N2369 in the original but another 2N3904 in the kit.

I do have an original JA board which is currently not working so I'll cross check with that and hopefully end up with both working :)

Cheers.

Phill.
Last edited by Prime on Wed May 07, 2014 11:24 am, edited 1 time in total.
acsi
Posts: 48
Joined: Tue Apr 23, 2013 12:03 pm
Location: New Zealand

Re: Jupiter ACE Kit /sorry half off-topic! :)/

Post by acsi »

Ill be interested as I have the same result with mine.
Prime
Posts: 134
Joined: Thu Mar 24, 2011 3:02 am

Re: Jupiter ACE Kit /sorry half off-topic! :)/

Post by Prime »

Ok, doing some reading on common emitter transistor switches I think the problem is that the signal being applied to the base is too great to ever allow Q2 to switch off.

I think the solution to this is to alter the value of R7, I'll do some experements this evening and post my results here.

Cheers.

Phill.
Post Reply