Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!killer!elg
From: elg@killer.UUCP (Eric Green)
Newsgroups: comp.sys.cbm
Subject: Re: Burst Mode on C-64 ?
Message-ID: <4241@killer.UUCP>
Date: 31 May 88 06:34:49 GMT
References: <1988May27.175829.5648@ziebmef.uucp>
Distribution: na
Organization: The Unix(R) Connection, Dallas, Texas
Lines: 22

in article <1988May27.175829.5648@ziebmef.uucp>, ross@ziebmef.uucp (Ross Ridge) says:
> On a local BBS we had a discussion about burst mode on the 64. We thought the
> biggest problem would be be the hardware modifications, but our goal was to
> be able to do it through software only. The CIA's (6526) serial port *could*
> be emulated through software (side note: the 64 can go as high ar 4800 baud
> or 7200 half-duplex if you completely re-write the RS232 routines) however
> burst mode used serial line that wasn't connected on the 64...

Note that bit-rate for each byte during burst mode is 250,000 baud, not 4800
baud. Burst mode is FAST. With the 1581, which reads data off disk at a
reasonable rate, the 128 is almost as useful as a real computer.

You'll never do it in software. In particular, the 1581, in fast mode or burst
mode, clocks data out at 250,000 baud. No software in the world is going to be
able to sample fast enough to cope with that. Hardware is necessary. Period.
If you are doing true burst mode, and not just a software fastload/fastsave
routine. 

--
    Eric Lee Green                     {cuae2,ihnp4}!killer!elg
         Snail Mail P.O. Box 92191 Lafayette, LA 70509              
"Is a dream a lie if it don't come true, or is it something worse?"