Path: utzoo!utgpu!water!watmath!clyde!att!pacbell!ames!amdcad!sun!pitstop!sundc!seismo!uunet!mcvax!enea!diab!pf
From: pf@diab.se (Per Fogelstr|m)
Newsgroups: comp.arch
Subject: Re: Sw vs. Hw BitBlit (CharBLT)
Message-ID: <421@ma.diab.se>
Date: 21 Aug 88 08:17:30 GMT
References: <399@ma.diab.se> <76700044@p.cs.uiuc.edu> <1848@titan.camcon.co.uk> <1988Aug13.205229.24467@utzoo.uucp>
Reply-To: pf@ma.UUCP (Per Fogelstr|m)
Organization: Diab Data AB, Taby, Sweden
Lines: 15

In article <1988Aug13.205229.24467@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>In article <1848@titan.camcon.co.uk> anc@camcon.co.uk (Adrian Cockcroft) writes:
>>The Intel 82786 has a charblt instruction. There are two forms, in the nicest
>>one you define a font to the chip, up to 256 16x16 pixel characters...
>
>So if my characters are, say, 17x17, I can't use it?  This is precisely the
>sort of stupid restriction that makes people forget the chip and do it in
>software instead,

Intel always put a lot of dumb restrictions in their silicon. However it is 
possible to use larger fonts by using normal bitblit transfers. The sad thing
is that you cant take advantage of the special functions used by charblt.
(Table lookup etc.)  NS DP8500 also has a charblt instruction but this chip
can handle up to 65536 characters up to 256x256 pixels. Yes I know this is
an restriction as well, but i think it will last for a while.