[Coco] CoCo 32k rom architecture

[Barry Nelson]

Sorry, but that article talks in great detail about designs for a 64k and 128k program pak, but only briefly mentions the 32k paks, which use a different system. I am not interested in breaking the 32k barrier at this time I am just interested in reaching it and in the workings of the standard 32k paks for the CoCo 3 and the format or the .ccc files for these paks. The larger ones can wait for now. I need to understand how the .ccc file layout is ordered, how the rom chip is ordered, and how the 32k mode is activated. Also on my mind is if the 32k paks use the SLENB line to control the bus and allow access to the extra memory space?

 

>        Robert Gault robert.gault at att.net  <mailto:coco%40maltedmedia.com?Subject=Re%3A%20%5BCoco%5D%20CoCo%2032k%20rom%20architecture&In-Reply-To=%3C56A786C3.9030102%40att.net%3E> 
Tue Jan 26 09:46:27 EST 2016 

 

>        > Barry Nelson wrote:

>     >  I am trying to write an image of a 32k rom pak into a chip and have the CoCo 3 run it. What can anyone tell me about the architecture of Tandy's 32 games such as Arkanoid, Rampage, etc? How did they map the 32k into the CoCo 3 address space? Did they have any special hardware in the pak besides the rom chip? How did the CoCo 3's addresses map onto the address space of the rom? How does all this relate to the layout of a 32k .ccc file?

>         > 
 
>         Barry,
 
>         There is a complete description on this subject in "Breaking the 32K Barrier" by 
>         Greg Zumwalt, "The Rainbow", June 1990, p58.
 
>         Robert