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Commit Graph

8 Commits

Author SHA1 Message Date
Oliver Schmidt
73faf60fe0 Support randomize().
In order to have randomize() work as expected (and the Apple II random number generation in general) it is necessary to update the random counter during keypress wait just like the ROM function does.
2018-09-08 18:45:20 +02:00
Oliver Schmidt
e47485f925 Added CONIO cursor support.
For quite some time I deliberately didn't add cursor support to the Apple II CONIO imöplementation. I consider it inappropriate to increase the size of cgetc() unduly for a rather seldom used feature.

There's no hardware cursor on the Apple II so displaying a cursor during keyboard input means reading the character stored at the cursor location, writing the cursor character, reading the keyboard and finally writing back the character read initially.

The naive approach is to reuse the part of cputc() that determines the memory location of the character at the cursor position in order to read the character stored there. However that means to add at least one additional JSR / RTS pair to cputc() adding 4 bytes and 12 cycles :-( Apart from that this approach means still a "too" large cgetc().

The approach implemented instead is to include all functionality required by cgetc() into cputc() - which is to read the current character before writing a new one. This may seem surprising at first glance but an LDA(),Y / TAX sequence adds only 3 bytes and 7 cycles so it cheaper than the JSR / RTS pair and allows to brings down the code increase in cgetc() down to a reasonable value.

However so far the internal cputc() code in question saved the X register. Now it uses the X register to return the old character present before writing the new character for cgetc(). This requires some rather small adjustments in other functions using that internal cputc() code.
2016-06-19 15:03:20 +02:00
Oliver Schmidt
85885001b1 Removed (pretty inconsistently used) tab chars from source code base. 2013-05-09 13:57:12 +02:00
ol.sc
5741b6e7d3 Minor comment style adjustment.
git-svn-id: svn://svn.cc65.org/cc65/trunk@4717 b7a2c559-68d2-44c3-8de9-860c34a00d81
2010-06-07 19:20:10 +00:00
cuz
b0117e1e22 New cgetc with apple2enh fix from Oliver Scmidt
git-svn-id: svn://svn.cc65.org/cc65/trunk@3454 b7a2c559-68d2-44c3-8de9-860c34a00d81
2005-04-08 19:27:07 +00:00
cuz
071c58bda2 New version from Oliver Schmidt
git-svn-id: svn://svn.cc65.org/cc65/trunk@3421 b7a2c559-68d2-44c3-8de9-860c34a00d81
2005-03-26 17:03:30 +00:00
cuz
a57deeb58a Reworked version by Oliver Schmidt
git-svn-id: svn://svn.cc65.org/cc65/trunk@2913 b7a2c559-68d2-44c3-8de9-860c34a00d81
2004-03-11 21:54:22 +00:00
uz
53dd513176 This commit was generated by cvs2svn to compensate for changes in r2,
which included commits to RCS files with non-trunk default branches.


git-svn-id: svn://svn.cc65.org/cc65/trunk@3 b7a2c559-68d2-44c3-8de9-860c34a00d81
2000-05-28 13:40:48 +00:00