Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!swrinde!ucsd!ogicse!intelhf!agora!billsey
From: billsey@agora.uucp (Bill Seymour)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Can an IBM power supply live on an Amiga 2000?
Message-ID: <1990Nov18.060002.21101@agora.uucp>
Date: 18 Nov 90 06:00:02 GMT
References: <7652@cica.cica.indiana.edu> <15799@cbmvax.commodore.com>
Distribution: na
Organization: Open Communications Forum
Lines: 33

In article <15799@cbmvax.commodore.com> daveh@cbmvax.commodore.com (Dave Haynie) writes:
:In article <7652@cica.cica.indiana.edu> graham@venus.iucf.indiana.edu writes:
::In article <90313.094443MBDZM@ROHVM1.BITNET>, MBDZM@ROHVM1.BITNET writes...
:::The voltages seem to
:::be ok +5, -5, +12, -12, but there is a line marked "TIC". That is the one
:::I can't figure out.  Is it there on the IBM supply? Can I fake it?
:
::Darn! Wish I had my notes with me.
:
:The TICK line is a 50/60Hz output clock from the line.  Since in most areas,
:the power line frequency is regulated for use with clocks, the Amiga's
:run-time clock gets its timebase from this.  It is possible to run an A2000
:using the VSYNC line (which is a tad under 60Hz on an NTSC system) instead
:of TICK by changing the J300 jumper, which is between the U300 CIA chip and
:the Paula chip on the motherboard.  The A500 always uses this for its
:timebase, and it works, its just not as accurate as the line voltage.

	The problem with switching the J300 jumper doesn't come into
play until you try to hook up a peripheral that uses HSync... Some
that come to mind are the Flicker Fixer, SuperGen and the 2320. These
will not work right unless you have a real 'TICK' signal. :-(

:-- 
:Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
:   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
:	Standing on the shoulders of giants leaves me cold	-REM


-- 
     -Bill Seymour                                            billsey@agora
***** American People/Link Amiga Zone Hardware Specialist  NES*BILL *****
Bejed, Inc.       NES, Inc.        Northwest Amiga Group    At Home Sometimes
(503) 281-8153    (503) 246-9311   (503) 656-7393 BBS       (503) 640-0842