Stupid eBay user du jor

Tony Duell ard at p850ug1.demon.co.uk
Sun Feb 26 14:17:14 CST 2006


> I wonder how fast I can refresh an 80x24 VT display over a 19200 Baud RS232
> link...

Well, if you hae to re-write the entire screen each time : 

19200, assuming 10 bits per character (start, 8 data, 1 stop) is 1920 
characters/second. Your screen has 1920 characters. So one full screen 
per second, maximum

I am told that the origianl spec for the PERQ rasterop machine was that 
it should be as fast at updating text as a normal serial terminal 
(remember the PERQ didn't have a text mode, just a bitmapped mode). It 
was estimated that the speed of a good terminal was one full screen per 
second. In fact the PERQ easily beat it -- the peak speed, assuming all 
you were doing was displaying things on the screen, was nearer 10 full 
screens per second, and that's a full PERQ secreen, which displays 
something like 80*66 characters.

-tony



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