IBM PCjr Colorpaint notes

• [TBD] I should go upload a 64k and 2x32k image here
• It does some initial probing to see if there’s a disk controller!
• .. If it finds one then it installs itself as a DOS command (‘g’).
• .. If it doesn’t find one then it starts immediately.
• DOS ROM extension commands only work with PC-DOS - so no, you can’t use MS-DOS here!

It likely installs itself as a DOS extension command in order to use DOS interrupts for the file IO. Apparently this is a common thing done by IBM PCjr cartridge software to avoid needing DOS in ROM. (Although wouldn’t DOS in ROM be actually quite useful?)

What about a manual?

I haven’t found a manual yet online!

So, some usage notes!

• it runs in 640x200x4 colour mode
• Right click the 4 colours to cycle through the hardware palette options
• When drawing circles, squares, lines - you use left click to size, and right click to actually draw them!