[Coco] [Color Computer] WordPak RS/CO80

[Boisy Pitre]

As part of on-going work with NitrOS-9, I am trying to validate the 
CO80 driver that is part of the NitrOS-9/6809 Level 1 package with a 
WordPak RS 80 column cartridge that I am borrowing.  The CO80 driver 
assembles to the exact same driver that was part of the OS-9 Level One 
V2 upgrade.

Currently, when I initialize the card, I am seeing what appears to be 
out of phase junk on the 80 column mono monitor that is hooked up to 
the card.  I've established that the monitor works.  I've even booted 
up the CoCo 2 that I am using into OS-9 Level One V2, loaded the stock 
CO80 driver into memory and did TMODE TYP=2 to start up the driver, and 
still get the same random garbage on the monitor.  So either my WordPak 
RS is bad or CO80 was written for some other WordPak (I recall there 
were several variants).

I looked inside the WordPak RS and it appears to be based on a Rockwell 
6545A CRT video chip.  I found the data sheet on this chip and the 
register access methods look nothing like what the CO80 co-driver is 
doing, which leads me to suspect the WordPak RS as the proper 80 column 
card for the CO80 co-driver.

- With all of that said, can someone with a WordPak card verify that 
CO80 works on their system?
- Does anyone have documentation on how the WordPak RS interfaces to 
the CoCo?  From looking at the driver source and poking around, my best 
estimate is that the card is mapped to $FF78-$FF79, and that $FF79 is 
some type of internal addressing register, and $FF78 is the data 
register.  Like I said, looking at the R6545-1 datasheet that I have, 
the accesses in the driver do not seem to make sense.

Any light that can be shed on this would be appreciated.

Boisy






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