Re: Data Becker CBM-8000 hi-res graphics

From: David Holz <>
Date: Tue, 5 Sep 2017 07:32:20 -0700
Message-ID: <>
By the way, I was looking for text and BASIC tokens, and I don't see
any.  There's actually very little non-asm data at all in the ROM, after
tracing the initial JMP table and the IRQ handler at 97b6.

At 9069, right after the jump table, is this:  Given the angle brackets with 2 spaces
after them, it might be some sort of prompt or display.  The code at
9db8 loads 0937/8 with 9069, and I think that's the only reference.  No
clue what the $1b is used for, though.  There's only 1 "xxx #$1b" at
9df0, and it doesn't seem related.

At 9512 is a bit table:  80 40 20 10 08 04 02 01

9cc6 has a potential block/line drawing character table, as mentioned:  It's used to compare against 03da in a
long chain of tests starting at 99d5

The most curious is at 9d58, which does seem to be some sort of printout
routine with X and Y:  The only
reference to those addresses seem to be the lda/ldx uses above, so this
might be able to be a useful starting point.

And the most entertaining is the end of the image, where there's some
leftover source code text: :)

Beyond that, there's no other data or text in the ROM image,
unfortunately.  It's all code.

[I don't know if the list supports attached images, or handles Unicode
for the PETSCII conversions, so I just pasted screenshots]

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Received on 2017-09-05 15:00:03

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