P2 Video Driver for a coco 3 emulator?
Hi, perhaps somebody wants to give me some hints?
For my project https://forums.parallax.com/discussion/174794/towards-os9-operating-system-on-p2#latest
I want to start with an emulator, which works with a serial terminal connection.
But when I read about OS9, then the most used implementation by far was Tandy Color Computer 3. It's Screen could be switched with a keystroke to a different application. Software uses simple windows. So it would be very attractive to have video output. Unfortunately video output for P2 and for coco-3 are big additional learning fields for me....
The best description of the data format, that I have found up to now is here, chapter 4: https://colorcomputerarchive.com/repo/Documents/Books/Assembly%20Language%20Programming%20for%20the%20CoCo3%20(1987)%20(Laurence%20A%20Tepolt).pdf
As far as I understand, maximum Ram requirement is 2 colorbits640256=40k for graphics. I am using no external Ram. I would need an approach for a simple mind using FlexProp.... P2 is running at 200MHz. Output is a VGA-Monitor.
So my question is: Which of the video-drivers for P2 can output text and graphics data, that is given by coco-3 software? Will I need a translation-cog that reads the data and outputs with an own second video buffer?
Of course the register settings have to be translated to driver settings, so I must be able to understand things. Start shall be with a subset of modes.
Any hints appreciated! Christof