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Path: utzoo!decvax!wanginst!apollo!nazgul
From: nazgul@apollo.uucp (Kee Hinckley)
Newsgroups: net.micro.apple
Subject: Re: Double Hi-Resolution Graphics on IIe (Information Request)
Message-ID: <2b32a187.7005@apollo.uucp>
Date: Tue, 7-Jan-86 16:51:49 EST
Article-I.D.: apollo.2b32a187.7005
Posted: Tue Jan  7 16:51:49 1986
Date-Received: Wed, 8-Jan-86 03:08:26 EST
References: <771@alberta.UUCP>
Reply-To: nazgul@apollo.UUCP (Kee Hinckley)
Distribution: na
Organization: Apollo Computer Inc., Chelmsford MA
Lines: 64
Summary: 

In article <771@alberta.UUCP> gordon@alberta.UUCP (Gordon Atwood) writes:
> Some time ago I posted a request for information on the use of double
> hi-resolution graphics with the Apple IIe.  The response was overwhelmingly
> non-existant.

That's typical.

> Has anyone out there examined this supposed feature?  Can anyone explain how
> to use it, either from Basic, or Machine Language level.  Does anyone know
> if certain models of IIe might be lacking this feature?  Can anyone recommend
> an article, text, person, which/who can supply this information?
> 
> Any assistance with this problem would be greatly appreciated.
> 
> G.H.A.

Well, you asked for any assistance, so I will offer up what little I know.

To use double hi-res on a ][e you need to have the following:
    an 80 column card with 64K of additional memory (apple compatable)
    a rev B motherboard
    a jumper

The revision notice is (I think) printed in the back behind the slots.  The
rev B board has been standard for at least a year, probably two.  I think
you can get a free upgrade if you don't have it.

The jumper has to go on the 80 column card, connecting two posts on the
right-hand keyboard side.  I'm a little vague on this, I don't have my apple
here and it has been a while since I did it.  Any kind of wiring between the
two posts will do.  I don't know whether this is done for you on the newer
versions of the 80-column card.

Once you have made sure that all of the above is done you can use the 80
column features.  The addressing is a real pain, since every other dot is
on the other bank of memory.  I know that Nybble magazine had a flurry
of sample programs that did it soon after it was announced, so you might
want to try and dig them up.  I've also seen (I don't remember where)
an ad for some ampersand routines that mimiced the standard apple
graphics calls but worked with hires.

As a side note, since the bank switching really slows down loading files
into memory some graphics programs (The Complete Graphics System
from Penquin Software in particular) save double hi-res pictures as
two seperate files, one for the foreground memory and one for the
background.

You can also use some of the extra memory for a ram disk.  This is
done automatically in ProDos and Nybble published a ram-disk
for Dos a while back that works quite nicely.

Hope that helps some.

                                                      Kee Hinckley
                                         ...decvax!wanginst!apollo!nazgul
--
    Little Bo-Peep
    Has lost her sheep,
The radar has failed to find them.
    They'll all, face to face,
    Meet in parallel space,
Preceding their leaders behind them.

                        "A Space Child's Mother Goose"