[Coco] DragonPy ... Dragon 32 / 64 and CoCo are alive...

[Jens]

Am 05.08.2014 um 18:44 schrieb cocolist at jensdiemer.de:
> I started to add a CoCo, too. But don't know much about CoCo. Seems that CoCo 1
> and 2 are very similar to the Dragon Hardware, but CoCo 3 is more advanced.
>
> At least i have to change the keyboard matrix.
>
> I just used the CoCo "Color BASIC v1.3" ROM... It's "boots up" and i see the
> color animated cursor... But input doesn't work yet. Maybe the PIA kerboard
> polling is a little bit changed, than the Dragon ROM code...

Since yesterday, input works, with commit:
https://github.com/jedie/DragonPy/commit/fd88b5cdb71e3bd7a07b9a4c9112dcbacf3705ed


The keyboard scan routine in CoCo ROM works a little bit other than the Dragon 
ones... The Dragon scan only the row and compare it with the last scan. The CoCo 
seems to scan all rows.

The Dragon ROM does this:

read $ff00 ($ff02 is $00 00000000) # Scan all
read $ff00 ($ff02 is $ff 11111111)
read $ff00 ($ff02 is $fe 11111110) # start scan
read $ff00 ($ff02 is $fd 11111101)
read $ff00 ($ff02 is $fb 11111011)
...and so on...


The CoCo starts directly with:

read $ff00 ($ff02 is $fe 11111110) # start scan
read $ff00 ($ff02 is $fd 11111101)
read $ff00 ($ff02 is $fb 11111011)
...and so on...




https://github.com/jedie/DragonPy



-- 

Mfg.

Jens Diemer


----
http://www.jensdiemer.de