Path: utzoo!attcan!uunet!husc6!mailrus!ames!pasteur!cory.Berkeley.EDU!koster
From: koster@cory.Berkeley.EDU (Herbert West)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Blitter minterms
Message-ID: <4901@pasteur.Berkeley.EDU>
Date: 8 Aug 88 17:41:26 GMT
References: <2965@umd5.umd.edu>
Sender: news@pasteur.Berkeley.EDU
Reply-To: koster@cory.Berkeley.EDU.UUCP (Herbert West)
Organization: University of California, Berkeley
Lines: 23

In article <2965@umd5.umd.edu> brett@pigpen.UMD.EDU (Brett S Bourbin) writes:
>Since the Blitter has three channels and one destination, can I do some
>math on the dest? ie. Could I make a minterm to OR sources A, B and C
>into the destination address D?  

Certainly! It would be $FE. Look at it like this:
The blitter is a table look up device. Sources A,B, and C have values of
4,2 and 1 respectively. They form a 3 bit binary number, with A as the most
significant digit: ABC

Now just make up 8 bits for what you want its output to be, given all possible
ABC combinations(only 8)

000    We want 0
001    1
010    1
011    1
100    1
101    1
110    1
111    1

Now put the bits together sideways: 11111110 = minterm, $FE