Path: utzoo!attcan!uunet!lll-winken!ncis.llnl.gov!helios.ee.lbl.gov!pasteur!ucbvax!hplabs!hp-ses!hpcea!hpausla!jcl
From: jcl@hpausla.HP.COM (Jeff Laing)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Text Drawing at speeds in excess of 1200baud
Message-ID: <2580010@hpausla.HP.COM>
Date: 19 Jan 89 06:59:03 GMT
References: <8276@orstcs.CS.ORST.EDU>
Organization: HP Australian Software Operation
Lines: 19

George Gonzalez (grg@berlin.acss.umn.edu) writes in comp.sys.mac.programmer:
> Here's how to speed up your serial I/O to screen.  I wish Red Ryder and
> Microphone were listening.

Me too.

> (2) You then may find the bottleneck is in scrolling the screen.  You can
> speed this up by scrolling up several lines at a time.  This is somewhat ugly
> but at 9600 baud the eye can barely tell if you're scrolling 1 or 3 lines
> at a time.

I found it was quite fast enough.  However, you don't maintain an 80 x 24 char
array of your screen image, but 24, 80 character buffers and a 24 buffer
pointer array.  When you scroll, use ScrollRect for the onscreen stuff and
just roll the 24 pointers around; if your update processing indirects through
the pointer array, it works fine.

Oh, it also means you don't have lots of hidden 'multiply by 80's in your
generated machine code, either.