Michael J. Mahon wrote:
Another possibility is that the text ROM or the text shift register are not working. The "block graphics" may not be lo-res graphics at all, but rather a stuck video data pattern.
However, in that case typing GR should make a difference in the look of the screen. Try if your system reacts in any way to typing GR (except for cleaning the upper part of the screen that is.)
-- Linards Ticmanis The Master said, "The business of laying on the colors follows the preparation of the plain ground."