Re: IIe reverse character display problems

[david@wraith.its.uow.edu.au (David E A Wilson)]

dalloff@freenet.columbus.oh.us (Dave Althoff) writes:
>...But in my collection, the number of programs that MouseText trashes far
>outnumber the ones that support it.  Mousetext has caused me nothing but
>trouble.

Which is why when I upgraded my first //e to enhanced status I burned a 2764
with mousetext in one half and the old inverse set in the other half and put
that in the chargen socket (admittedly here in Australia that is easier than
in the USA as our //e's came with PAL motherboards and 2764 chargens with
the UK set in one half and standard ASCII in the other half and a switch under
the keyboard to select between the two [the only difference between the two
sets was that one had the crosshatch while the other had the UK pound symbol]).
For information on how to do this to a US //e read Jim Sather's Understanding
the Apple //e as it contains instructions for this mod. 

Does everyone know why that group of reverse video uppercase characters was
changed to mousetext and not the more obvious one? From what I have read
and worked out this is the reason:

Range		Standard		Alternate
00-1F		Inverse Uppercase	Inverse Uppercase
20-3F		Inverse Special		Inverse Special
40-5F		Flashing Uppercase	Inverse Uppercase/Mousetext
60-7F		Flashing Special	Inverse Lowercase
80-9F		Uppercase		Uppercase
A0-BF		Special			Special
C0-DF		Uppercase		Uppercase
E0-FF		Lowercase		Lowercase

The ROM only has the alternate set. The standard set is created by mapping
40-7F alternately into 00-3F and 80-BF at the flash rate. Thus the extra
normal Uppercase at 80-9F could not be changed and nor could the Inverse
uppercase from 00-1F as that would have messed up both the flashing & inverse
uppercase in standard mode.
-- 
David Wilson	Dept CompSci Uni Wollongong Australia	david@cs.uow.edu.au