Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!husc6!cs.utexas.edu!uunet!cbmvax!fred
From: fred@cbmvax.UUCP (Fred Bowen)
Newsgroups: comp.sys.cbm
Subject: Re: C64 OKIMATE-10 PRINTER TROUBLE.
Message-ID: <6747@cbmvax.UUCP>
Date: 3 May 89 12:14:43 GMT
References: <12636@ihlpy.ATT.COM> <1613@alva.tut.fi>
Reply-To: fred@cbmvax.UUCP (Fred Bowen)
Organization: Commodore Technology, West Chester, PA
Lines: 29

In article <1613@alva.tut.fi> po87553@alva.UUCP (Ojala Pasi Juhani) writes:
>In article <12636@ihlpy.ATT.COM> rsbrd@ihlpy.ATT.COM (Byrd) writes:
>>  ........
>>  C64<------>1st disk drive<---->2nd disk drive<---->printer
>>  ........
>>I don't know whether it is a printer problem, a print control module
>>problem or an operator problem. Any hints .....
>
>  I once (in fact more than once) connected 1581,1541 and Star NL-10 to
>my c64 and wondered why the computer acted so weird... It resetted by
>himself and lost disk files. I disconnected the other drive and it works
>fine now. The weirdest thing is that when those 3 devices are ALL on,
>it worked fine, but if one or more is off system will crash sooner or later..

It should be well known by now that any serial bus devices must be turned on
or disconnected from the serial bus.  In the C64, the internal and external
reset lines are linked such that any device which pulls reset low (which is
what can happen when the device is turned off) can affect the rest of the
system as described above.  In the C128, the internal and external reset lines
are separated by a buffer.  Here, the only affect of an unpowered device on
the serial bus would be confined to the peripherals sharing the external reset
signal- including disks, printers, and modems.
--
-- 
Fred Bowen			uucp:	{uunet|rutgers|pyramid}!cbmvax!fred
				arpa:	cbmvax!fred@uunet.uu.net
				tele:	215 431-9100

Commodore Electronics, Ltd.,  1200 Wilson Drive,  West Chester,  PA,  19380