The TI 99 had some interesting design choices. The CPU had a very small amount of SRAM, 128 bytes IIRC, because it couldn't easily use DRAMs, which were much cheaper. The BASIC interpreter in ROM would read the program from the VDP's memory (which was DRAM) and interpret it, storing data back into the display controller's memory. It was a really nice 16-bit minicomputer CPU with one of the ugliest hacks around it to make it fit a home computer budget. Legend says IBM almost settled on the TI99's CPU instead of the 8088 for the IBM PC (they also mused about plain acquiring Atari) but didn't go for it because TI would be the single source for the component.
The same VDP would be the basis of the MSX, Master System and a couple others.
The TI 99 had some interesting design choices. The CPU had a very small amount of SRAM, 128 bytes IIRC, because it couldn't easily use DRAMs, which were much cheaper. The BASIC interpreter in ROM would read the program from the VDP's memory (which was DRAM) and interpret it, storing data back into the display controller's memory. It was a really nice 16-bit minicomputer CPU with one of the ugliest hacks around it to make it fit a home computer budget. Legend says IBM almost settled on the TI99's CPU instead of the 8088 for the IBM PC (they also mused about plain acquiring Atari) but didn't go for it because TI would be the single source for the component.
The same VDP would be the basis of the MSX, Master System and a couple others.