5 Apr
2010
5 Apr
'10
3:18 p.m.
On 4/5/10, M H Stein <dm561 at torfree.net> wrote:
----------------Original Message:
Date: Mon, 5 Apr 2010 02:13:20 -0400
From: Ethan Dicks <ethan.dicks at gmail.com>
Subject: Anyone have an image of a Japanese PET chrgen ROM 901447-12?
It would certainly be nice to find the
'official' ROM, but I thought that
the ROM that Philip (the owner of that PET on your bench) created
was pretty well complete and correct; it seems to match my Japanese
keyboard perfectly except for one character, and I suspect it's the key
that's wrong and not the CG.
Why would the key be wrong?
Did you try that image and match it up to your
Japanese chiclet
keyboard?
I have not. If you could send me a copy of it off-list, that would be
appreciated. I don't seem to have it in the place I store such things
(though I do remember the conversation).
I've been playing with the idea of having all
three (four?) character sets
available on screen at the same time, using the reverse video signal.
How would that work? Obviously, you'd use some new means of toggling
upper bits on the CHRGEN ROM, but I don't get how the reverse video
signal would be the trigger... the upper bit on a PET character cell
inverts the data out of the bit shifter (unlike the C-64 where it's
just another address bit). I can see how you could steal that upper
bit and pipe it into A11 on a larger CHRGEN ROM, but how do you get 3
or 4 sets from one bit?
-ethan