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From: jeff@alberta.UUCP (C. J. Sampson)
Newsgroups: net.micro.pc
Subject: Re: APL Query
Message-ID: <343@alberta.UUCP>
Date: Sat, 11-Aug-84 00:18:26 EDT
Article-I.D.: alberta.343
Posted: Sat Aug 11 00:18:26 1984
Date-Received: Sun, 29-Jul-84 23:59:08 EDT
References: <325@watdcsu.UUCP> <3018@rabbit.UUCP>
Organization: his Personal Computer
Lines: 42

[This "feature" gets rid of all those annoying first lines...]

>>> Tom Haapanen states that IBM APL for the PC will not display upper/lower
>>> case characters at the same time as APL characters.  This is false.

>> If I was wrong, I stand corrected.  However, consider the following:
>> The IBM APL does not use a different character generator ROM.
>> Instead, it uses the colour/graphics card's facility to redefine the
>> character set in software, which only allows for the use of 128
>> characters at a time.  I am amazed if IBM managed to squeeze uppper
>> and lower case (total: 52 chars), numbers (10 chars), APL symbols
>> (around 45 at least, not counting overstrikes) and other punctuation
>> into 127 characters!  They definitely left out things like line
>> drawing characters and foreign language symbols (all of which are in
>> STSC's APL) if this is the case.

>I do not have access to definite information about the IBM APL's
>character generation methods.  However, its character set is 256
>characters, not 128.  It looks like it generates the characters
>itself, rather than using the BIOS facilities, but maybe not.
>In any event, they managed to squeeze upper case, lower case,
>numbers, APL symbols, AND all the line drawing characters and
>foreign symbols into the character set.

I doubt that it would do all of its character generation itself.  If you
look at the ROM BIOS listing in the back of the technical refrence 
manual, you will see that they have the first 128 characters (control
chars, letters, numbers, etc.) defined in ROM, and the other 128 have
to be defined in RAM somewhere.  It is very easy to fit the entire APL
character set and the line drawing set in 128 characters, and you have
the other 128 predefined as your letters and numbers.  Take a look at 
the Waterloo APL chip's character set for an example of this.


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