Hires-HAM wouldn't made alot of sense as you can only use 4Bits.
2 for mode (R,G,B or direct color) leaves only 2Bits for data.
So you'd have 4 direct colors and set every gun to only 4 values.... not very usefull for a mode only sensible for displaying pictures ....
But there was a pseudo-HAM mode were a viever would let the copper set a new pallete on every new line. Quite impressive results ....
