* Added an important ".code" directive.
* Import a linker-created zero-page symbol as an absolute address; then, convert it to zero-page when it is used.
Fixes bug report #198.
The driver kernels all require IRQ handling even if the actual drivers don't make use of it. So in order to successfully link a NES program using the joystick and/or TGI driver there has to be at least a "dummy" IRQ backend.
That parameter's type is unsigned; but, the functions return an int. If the size is too big for a signed integer, then return an error code.
If the size is zero, then don't write anything into a buffer (the buffer pointer may be NULL). But, do format and count the arguments.
The starting point is the CALL2051:REM <cmdline> approach. It uses the BASIC input buffer at $200. ProDOS stores the name of the loaded program at $280 (which we want for argv[0]) leaving us with 128 char buffer. If we run the program via exec() we don't need the CALL2051 but only the REM token (which is just one char). So have a maximum cmdline length of 126 (plus a terminating zero).
There's no specification for ProDOS BIN file cmdline parameters so exec() just supports the CALL2051:REM <cmdline> approach. In contrast ProDOS SYS files allow for a 'startup filename'. A ProDOS filename is short than 126 chars so having exec() general cut the cmdline after 126 chars seems reasonable. If the SYS file we exec() allows for less we cut the cmdline further.
Our 'loader.system' SYS file however allows for an unusually 126 char long "startup filename" as it is targeted towards cc65 BIN porgrams with their 126 cmdline length.
Experiments show that under BASIC by default
25 rows by 24 columns are used. 24 columns is
also the width that is fully displayed on a real
C1P on the monitor. conio now matches that now.
If kbhit() detects that a key is pressed, it fetches and
buffers the character. If cgetc() detects a buffered character,
this one is returned instead of fetching one with the PROM
routine.
Adjusted comment formatting in several assembler files.
Removed dummy kbhit() function, as it's better to get a linker
error than an implementation that does the wrong thing.
