Path: utzoo!mnetor!uunet!husc6!cmcl2!nrl-cmf!mailrus!umix!umich!mibte!gamma!ulysses!thumper!faline!bellcore!clyde!watmath!ccplumb
From: ccplumb@watmath.waterloo.edu (Colin Plumb)
Newsgroups: comp.sys.hp
Subject: Re: HP-28
Message-ID: <17754@watmath.waterloo.edu>
Date: 23 Mar 88 22:37:05 GMT
References: <12364@orchid.waterloo.edu>
Reply-To: ccplumb@watmath.waterloo.edu (Colin Plumb)
Organization: U of Waterloo, Ontario
Lines: 23
Confusion: U. of Waterloo, Ontario


bamcpherson@orchid.waterloo.edu (Brent) wrote:
>	3. How is the screen memory organized and can it be written
>	   to? Also, is there several screen modes such as
>	   text and/or graphics?

On the 28S, there are commands to read and write a screen bitmap.  It
comes out as a 544-character string, where the first byte corresponds
to the 8-pixel column at the start of the first text row, this
continues across until the 137th byte corresponds to the 8-pixel column
at the start of the second text row, etc., in the manner of sending
bitmaps to a dot-matrix printer.

You can use the logical operations (AND, OR, etc.) on such strings.

You can also write arbitrary text to any of the 4 display rows, and
make custom menus.

There is only 1 display mode, bitmap.
--
	-Colin (watmath!ccplumb)

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