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From: fred@cbmvax.commodore.com (Fred Bowen)
Newsgroups: comp.sys.cbm
Subject: Re: 1581 Questions
Message-ID: <10376@cbmvax.commodore.com>
Date: 27 Mar 90 15:42:01 GMT
References: <1990Mar12.170930.2984@sun.soe.clarkson.edu>
Reply-To: fred@cbmvax (Fred Bowen)
Organization: Commodore, West Chester, PA
Lines: 41

In article <1990Mar19.031805.16696@ccu.umanitoba.ca> Dan Fandrich writes:
>In article <1990Mar12.170930.2984@sun.soe.clarkson.edu> Glo writes:
>>Does anyone know how I could tell the difference between Version One and
>>Version Two of the 1581 Commodore disk drive?
>
>Try sending the reset command ("UJ" or "U;") to channel 15, then reading
>the error channel message.  This should result in two different messages
>depending on the ROM revision, but I only have a 1541 so I can't confirm
>this for the 1581.

There has never been a revision to the 1581 ROM.  Many folks confuse the
controller swap involving the first 1581's produced with a ROM swap.  The
easiest way to tell which controller is present is to look (although opening
the case will void your warranty).  The controller chip, which looks just
like a ROM chip, is in location U4.  It should be branded WD1772.  I had
posted many moons ago a short program which checked the controller type-
perhaps you can find a copy, or if necessary I can repost it.

>>How does the AUTOBOOT feature of the 1581 work? Will the 1581 autoboot using
>>a 64?
>
>You won't be able to autoboot anything with a C64 unless you have a modified
>kernel or a cartridge plugged in.  The support for autobooting just isn't
>in the ROM.

This is correct for the likely context of the question.  Some folks, however,
are confused by the two functions called 'autoboot'.  From the computer's
point of view, it means automatically loading a program into the computer
and running it.  The stock C64 will not do this.  There is another type of
'autobooting' documented in the 1581 manual.  This is a rarely used facility
which causes the drive itself to load a program into *its* memory and run
it.  This can be very tricky, but could be used, for example, to renumber
the drive, change its step rate, etc. without even having it connected to a
computer.  Refer to the drive's manual for details.
--
-- 
Fred Bowen			uucp:	{uunet|rutgers|pyramid}!cbmvax!fred
				domain:	fred@cbmvax.commodore.com
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Commodore Electronics, Ltd.,  1200 Wilson Drive,  West Chester,  PA,  19380