DECDLD usage -good enough for minimal graphics?

VT220 does not have graphics, but does have an available down-line-loadable character set. DECDLD is the (protocol?) that is used to transfer the custom fonts to the terminal. I was wondering how fast it does this - from what I can gather, using this method you can redefine and line up the characters so that they form a picture, while still retaining the ROM character set. Am I totally off base about this? -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Paul Koning Sent: Monday, August 08, 2005 4:51 PM To: cctalk at classiccmp.org Subject: Re: DECDLD usage -good enough for minimal graphics? Julian> Hello everyone! I was just investigating the usage of DECDLD Julian> for defining a small graphic screen on my PDP11 during a Julian> program. Julian> When using a VT220 at 19200 baud, how fast can a screen be Julian> refreshed using DECDLD graphics? I was thinking of doing a Julian> multiplayer (4 player) game using this system. If you plan the graphics properly, sure, no problem. PLATO had multiplayer games long ago using 1200 baud lines. That was with a MUCH more efficient graphics encoding, though. Did you mean VT240? Unless my brain is going, VT220 is text only. VT240 supports REGIS, which is a simple graphics protocol (somewhat verbose in its encoding as I recall). Assuming that REGIS doesn't lose more than a factor of 16 in coding efficiency vs. PLATO -- which should be true -- you should be able to get a couple of refreshes per second. There are plenty of interactive games that can live with that. paul