Path: utzoo!lsuc!ncrcan!ziebmef!ross
From: ross@ziebmef.uucp (Ross Ridge)
Newsgroups: comp.sys.cbm
Subject: Re: Burst Mode on C-64 ?
Message-ID: <1988Jun5.024514.28021@ziebmef.uucp>
Date: 5 Jun 88 06:45:09 GMT
References: <1988May27.175829.5648@ziebmef.uucp> <4241@killer.UUCP>
Reply-To: ross@ziebmef.UUCP (Ross Ridge)
Distribution: na
Organization: Ziebmef Public Access BBS/Unix
Lines: 28
In article <4241@killer.UUCP> elg@killer.UUCP (Eric Green) writes:
>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.
>
250 000 baud? That's almost 32k a sec. and as I understand it burst mode is
only slightly faster than improved serial bus the 128/1571 uses. Hmm...
at that rate the CPU only has 64 cycles (at 2MHz) to do something with the
byte its recieved before it has to get the next byte. Kinda cutting
it close. Maybe your right, but there were some people in the discussion
who would've know all about burst mode, and nothing like 250 000 baud
came up. Oh, well I suppose it's a bit trivial anyways, I don't think
anyone's going to do it, because it would probably simpler just to get a
128.
--
l/ {uunet!mnetor!lsuc,utgpu}!ncrcan!ziebmef!ross //
[OO] or just call me Ross for short... [oo]
-()- -()-
db 6502 assembly forever! //