Stefan Dorndorf, author of XDOS, pointed out that retrieving the
default device by looking at an undocumented memory location won't
work in future XDOS versions.
He also showed a way to get the default device in a compatible
manner.
This change implements his method and adds a version check (XDOS
versions below 2.4 don't support this -- for them the behaviour
will be the same as, for example, AtariDOS: no notion of a default
drive).
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.
The final part of exec() called 'excexit' and only then restored the
stack pointer to its value at program entry. 'excexit' does all
cleanup (the same as '_exit()'), which means that on the atarixl
target the ROM is banked in again. On big programs the 'SP_save'
variable might reside at a high memory address which is no longer
accessible after the ROM has been banked in.
The change just moves the restoration of the stack pointer before
the call to 'excexit'.
Another change lets exec.s compile if UCASE_FILENAME is not defined.
And some other small cleanups, also in open.s.
- Adds new ENOEXEC error code, also used by Apple2 targets.
- Maximum command line length is 40, incl. program name. This is
an XDOS restriction.
- testcode/lib/tinyshell.c has been extended to be able to run
programs.
* libsrc/atari/ucase_fn.s: Fix handling if input parameter 'tmp2' is 0.
* libsrc/atari/open.s: Set 'tmp2' parameter for 'ucase_fn' if DEFAULT_DEVICE
is not defined.
About all CONIO functions offering a <...>xy variant call
popa
_gotoxy
By providing an internal gotoxy variant that starts with a popa all those CONIO function can be shortened by 3 bytes. As soon as program calls more than one CONIO function this means an overall code size reduction.
- use this function instead of directly looking at _dos_type in the included
targetutil and test programs
- fixes/improvements to the Atari runtime library regarding the recently
changed _dos_type values
- libsrc/atari/targetutil/w2cas.c: exit if no filename was entered
- add documentation for the new function
The Vic20 does not have kernal table entries for the following functions.
;-----------------------------------------------------------------------------
; Functions which are not in the kernal jump table for VIC-20 but are for C64
CINT := $E518
IOINIT := $FDF9
RAMTAS := $FD8D
All other kernal entries are the same as the C64, however, without this change, the startup code fails.
Without this change the vic20.lib builds incorrectly.
