Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!columbia!rutgers!cbmvax!grr
From: grr@cbmvax.cbm.UUCP (George Robbins)
Newsgroups: comp.sys.amiga
Subject: Re: Amiga Video
Message-ID: <1815@cbmvax.cbmvax.cbm.UUCP>
Date: Fri, 1-May-87 04:57:13 EDT
Article-I.D.: cbmvax.1815
Posted: Fri May  1 04:57:13 1987
Date-Received: Tue, 5-May-87 04:39:42 EDT
References: <456@uhccux.UUCP>
Reply-To: grr@cbmvax.UUCP (George Robbins)
Organization: Commodore Technology, West Chester, PA
Lines: 21

In article <456@uhccux.UUCP> yuan@uhccux.UUCP (Yuan Chang) writes:
>
>     I was quite puzzled by the presence of the "half-bright" mode in the
>Amiga.  If one extra bit-plane is used to get the extra shades, why not
>just use it to get twice as many colors as present in lo-res mode?  Surely
>this will be lot more flexible than the half-bright mode.....  Anyone care
>to comment on this?

According to my sources, half-brite was added as a way to extend the number
of colors without making changes too large at the point in time the feature
was added.

Using the extra bit-plane in the straight forward way would have required
doubling the size of the color lookup table which would have caused serious
chip layout problems and would have used up all or allmost all the available
chip register addresses.

-- 
George Robbins - now working for,	uucp: {ihnp4|seismo|rutgers}!cbmvax!grr
but no way officially representing	arpa: cbmvax!grr@seismo.css.GOV
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)