Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!asuvax!ukma!seismo!dimacs.rutgers.edu!aramis.rutgers.edu!remus.rutgers.edu!utopia.rutgers.edu!wilmott From: wilmott@utopia.rutgers.edu (Ray Wilmott) Newsgroups: comp.sys.atari.8bit Subject: 80 columns and baud rate Keywords: why? Message-ID: Date: 7 Apr 91 01:27:53 GMT Organization: Rutgers Univ., New Brunswick, N.J. Lines: 46 --- Okay, I ask forgiveness from all of you out there for posting this question without even bothering to seriously think about it, or trying to look up relevant information on the topic, but I just thought of something in passing a minute ago, and figured I'd put my foot in my mouth and ask... The question concerns 80 column (via software) term programs and the (apparent) 1200 baud limit. BobTerm, I've heard, works at up to 9600 baud just fine on an unmodified 8-bit in 40 column mode (I say *heard* because I don't have a 9600 baud modem to confirm it). I have 3 different 80 column VT100 terminal emulators, and 1200 baud is as high as they go. I've heard in discussions here and elsewhere that the reason for this is that what these programs are doing is actually drawing, character by character, every byte on a graphics 8 screen, and that there's so much overhead for doing this that the little old Atari can't keep up. That's all well and good, but wouldn't it be possible to patch directly into the OS and make the machine think that it's normal mode of operation is graphics 8, not graphics 0 and give it the 80 column character set as its normal character set, thus letting the OS directly deal with drawing the screen? No, this type of approach I wouldn't expect to yield the same 9600 baud rate since a "higher res" screen is being handled, but I would think that 2400 baud should be able to be achieved. Isn't a graphics 0 screen made up of 8x8 bit characters, 40 column across and 20 columns down? And a graphics 8 screen 320x192 pixels? (this is from memory so...) If so, thats 51,200 pixels versus 61,440 pixels. So why can one only go 1200 baud while the other can go 9600 baud? Seems to me its only because one *directly* uses the OS to draw the screen in a native manner, while the other fights against the OS to forcibly draw a slightly higher res screen. And so...wouldn't it be possible to patch into and rewrite part of the OS to make *it* naturally handle a graphics 8 screen of text? On the old 800 and 400 this would be a trick since the OS is in ROM, but on the XL/XE class machines, you could copy the OS to the RAM underneath and then just patch whatever you want in there. Again, this is just a brief idea, without much thought into the matter - I eagerly await someone to tell me where my reasoning is fouled up (or to prove me right and make a 2400 baud 80 col term). Thanks. -Ray