Re: Uther card works on Apple IIplus with contiki
- From: Oliver Schmidt <ol.sc@xxxxxx>
- Date: Sun, 10 Jul 2005 16:41:49 +0200
Hi Rob,
>> The "downlevel" version is known to be unable to load both the web
>> browser and a screen saver.
>Do you have any idea why this is so?
Of course - as I did it ;-)
>Both machines have the same amount
>of memory and if anything the "downlevel" version should be simpler.
>Does the //e version make use of 65c02 instructions to reduce memory usage?
1. Your guess is right. The cc65 C compiler allows to produce 65C02
instructions which reduce the code size. In fact even the assembler
parts of the cc65 C-Library are smaller because they often exist in an
optimized 65C02 version.
2. Contiki contains general purpose screen drawing code written in C
that creates windows from two horizontal lines, two vertical lines and
four corners. This code is used for the "downlevel" version while the
mousetext version uses custom code that creates a window by calling a
single C-Library assembler function available only for mousetext.
Beside that the custom code does no window clipping. That further
reduces code size but increases flicker - which I classified
acceptable due to the general high(er) drawing speed.
Best, Oliver
.
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