Jupiter Ace

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Mon Mar 17 18:36:38 2003

> Hi all,
> I'm now starting on the Jupiter Ace again and I've got one really big
> question that's been bugging me for a while. How the heck does the Jupiter
> Ace display *graphics* on-screen? It looks like the chargen is text-only and

It doesn't!.

You've noticed the problem. All you can do is redefine the characters
(acutally, it's worse than you think -- 1K bytes of RAM is 128 8*8
patterns -- the high bit of the character code is used to invert all the
dots in the pattern IIRC). And 256 chracters is not enough for the entire
screen.

That's why you can't have an arbitrray image on the screen. There was a
Jupiter Cantab untility to allow setting/reseting points, and one of the
error messages was something like 'All characters used' :-)

> I also need a 32-ohm speaker, circular, about 1 inch in size
> edge-to-edge. Has anyone got a spare for sale? These same speakers were

My obvious thought is that most cheap stereo headphones are 32 Ohm
impdedance, and about that size. How about raiding a pair?

-tony
Received on Mon Mar 17 2003 - 18:36:38 GMT