"the Tandy graphics memory was separate in the same way that the EGA graphics memory was separate---it was never used for program code." This is incorrect. The

"the Tandy graphics memory was separate in the same way that the EGA graphics memory was separate---it was never used for program code." This is incorrect. The Tandy graphics adapter did share ram with the cpu. The service manual for the Tandy 1000 can be found at http://www.thealmightyguru.com/Wiki/images/7/7c/Tandy_1000_-_Manual_-_Service.pdf http://www.thealmightyguru.com/Wiki/images/7/7c/Tandy_1000_-.... Starting on page 40 is a good description of how this worked.