That pesky Jupiter Ace *still* won't work...

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Tue May 27 18:03:35 2003

> Hi,
> I've just finished fixing the Ace's PCB using wire-wrap wire. All the
> broken tracks I've managed to find have been fixed and all the damaged
> through-hole plating has been repaired. Except there's one problem. The Ace
> *still* won't boot to the FORTH interpreter.

Argh!. There aren't that many chips in the machine...

> There is a load of garbage on the display - this seems to change while the

Garbage as in random dot patterns, or garbage as in characters? Is it
loading the character generator at all?

> machine is running. The power consumption of the board - CPU and all - is
> around 800mA (according to the crappy meter on my Farnell 1A bench PSU). I've

DOesn't sound excessive...

> got the output on the PSU set to 9V, no current limit.
> Does anyone here have a logic analyser or microprocessor debugger that I
> could borrow for a few days? I've got two scopes (a Tek 466 and a Gould

Where are you in the country? I am not lending out any of my test gear (I
depend on it too much!), but if it's physcially possible for us to get
close together, I can have a quick look and wave some probes over it...

> OS1100) and a Fluke 25 multimeter, but that's about it in terms of test
> equipment.
> Alternatively, does anyone know if a diagnostic ROM exists for the Ace?
> Something that would replace ROM A and just load the video/font RAM with the
> usual Ace character set would be very handy.

I believe the normal ROMs do that early on anyway.... I've never heard of
a diagnostic ROM for the ACE

> The 2114Ls I'm using appear to be OK, but they draw a lot of current - in
> the region of 75 to 100mA each.

YEs, they do eat current...

-tony
Received on Tue May 27 2003 - 18:03:35 BST