Comment by schlupa

The fundamental issue with BASIC on the TI-99/4A, be it the regular BASIC or even the Extended BASIC, is that the program was stored in the video memory. This meant that you couldn't use all features of the VDP, you could only use a limited number of tiles (96 afaicr), you could not use other graphics mode, raster interrupts and sprite multiplexing, forget it. The games on cartridges were not limited to that and could use up to 24K (afaicr) of machine code + a lot of GROM. One needs only to look at what a Coleco console or a MSX1 could do with a system that didn't use the graphic chip for what it was not intended to be.