Televideo Systems

Well, when you were running CP/M, these were text-only too. But they had 640 x 240 graphics, with primitives in ROM that sped things up quite a bit. DRI's GSX-80 came with the systems to provide a standard layer for the graphics support. Then DRI's CBASIC had language extensions for drawing lines and such. But the overhead was high, translating from a real-number world coordinate system to an integer normalized coordinate system and then to the integer physical device coordinate system. I bypassed all that using some assembly language interfaces I wrote and went straight to ROM. The application we'd written in CBASIC using its "native" graphics statements took 6 minutes to finish drawing the screen (an image of a prototyping board). The re-written version drew the same inage in six seconds on a 4MHz Z-80. -dq