DECDLD usage -good enough for minimal graphics?

John> recalling... I thought the problem with that was you could John> only define 256 characters at a time, and when you tried to John> load a new set of bitpatterns, all instances old and new John> onscreen would change, making only a picture with 256 unique John> cells (no more) possible. Don't know if this is a fact, but John> that's what the spec seemed to say to me at the time. A full John> screen could be up to more like 24x80=1920 characters. A lot John> could still be done with even that. Another possible problem: John> fixed inter-character gaps. Perhaps someone here has actually John> Done this. That sounds right. Given that the VT220 is a character display terminal, it's refreshing from a character buffer via the character bitmap memory. If the bitmap memory changes, so does the display. If you don't want that, you need a terminal with a bitmap display memory -- the VT240, or the PRO for that matter... Ignoring the issue of inter-char gaps (don't know about that, easy enough to test), you should aim for a graphic design where all the elements together can be encoded in however many fixed and programmable character bitpatterns there are. That way you load things once, and the display then becomes a changing pattern of characters. Again, that was common on PLATO, which had (62) loadable characters. For example, the display for PacMan could be done that way. paul