Re: PC Transporter

[kragen@dnaco.net (Kragen Sitaker)]

In article <7sjs50$lmj$1@chakotay.ncc74656.org>,
Scott Alfter <salfter@chakotay.ncc74656.org> wrote:
>8088s in general are slow.  The few times I've fired up my XT, I've been
>surprised by just how slow it is, especially at redrawing the screen (it's
>equipped with the original IBM CGA card, a full-length card that's subject
>to "snow" interference under certain circumstances).  An Apple II, even at
>the normal 1-MHz speed of the 8-bit machines, would keep up (or even outrun)
>it in most apps.

Yes, I've heard that too (although I don't have any XTs around to
compare my Apple with, and my 5x86-133 is considerably faster than the
Apple).  Why is that?

About the snow: that happened whenever you wrote to or read from video
RAM.  The RAM was single-ported, so a small bit of garbage would appear
on the screen wherever the raster happened to be when you accessed
video RAM with the CPU.  The solution was to do this only while the
raster was in the horizontal retrace interval or the vertical blanking
interval.

I hope I don't have to worry about the same thing on my Apple //e; I
haven't tried writing graphical programs in machine code yet on it.
-- 
<kragen@pobox.com>       Kragen Sitaker     <http://www.pobox.com/~kragen/>
Sat Sep 24 1999
44 days until the Internet stock bubble bursts on Monday, 1999-11-08.
<URL:http://www.pobox.com/~kragen/bubble.html>