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From: gad@linac.fnal.gov (Greg A. Deuerling)
Newsgroups: comp.sys.amiga.hardware
Subject: Refresh Questions
Message-ID: <3024@linac.fnal.gov>
Date: 21 Nov 90 18:22:52 GMT
Sender: gad@linac.fnal.gov
Organization: Fermilab, Batavia, IL
Lines: 18



I have recently finished a hardware project for my 2000.
The project only takes up half of my proto-board.  I have
a couple 1Meg X 8 SIP's laying around and I'd like to put
them on the un-used proto area.  My problem is I can't
figure out how to generate refresh for the ram on the 
proto board.  I know there are 4 refresh cycles at the
start of a Horizontal Scan.  One scan is around 63 micro-
seconds.  I can easily build a circuit that would initiate
a refresh, but how do I sync up to the start of the 
Horizontal Scan ????  The Hardware Reference Manual
explains all of this but it tells you nothing on how to
sync to the Horizontal Scan.

Any help at all would be greatly appreciated.

Thanks.							GAD.