[Coco] I fixed the goddamn PCLEAR 0 bug.

Allen Huffman alsplace at pobox.com
Fri Aug 1 18:06:29 EDT 2025


For those now following along — go watch that video on Juan’s dropbox. It’s quite cool.

> On Aug 1, 2025, at 4:59 PM, Juan Castro via Coco <coco at maltedmedia.com> wrote:
> 
> That particular check is standard in ECB. You can't PMODE into something
> for which you haven't PCLEARed enough, and you can't PCLEAR less than the
> current PMODE needs. My new checks are only for the new things: WIDTH and
> PCLEAR 0.

If I ever knew this, I forgot.

I guess I was unaware you could just do:

PMODE 0

…without the “,X” number after it.

Now that you have been in that code, is PCLEAR 0 a bug/oversight, do you think?

>> WIDTH 51 is surprising to me. Did you implement any other widths like that?
>> 
> 
> 51 (5px wide char cell) and 64 (4px wide char cell).


That is very cool. 16K rom, I suppose, to fit the font data? How does that work? CB was 8K, ECB was another 8K, and DECB was a third 8K. I suppose that means there is 8K left at the end of that 32K, minus the I/O area (256 bytes?).

Or am I just remembering nonsense?

		— Allen




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