* The 16-bit comparison code actually didn't compare the high byte.
* This implementation supports only the 1541, 1571, and 1581; but, it didn't exclude the other drive types that GEOS supports.
* Two error code numbers were swapped.
* A 1571 converter didn't catch sector numbers that are too high.
* A 1581 converter didn't catch sector numbers that are too high.
The unexpanded Creativision has only $206 bytes of RAM available to cc65 programs. So it's a bad idea(tm) to reserve $180 bytes for the software stack. $40 bytes seems a much better default (aka guess).
The change matches the way that I/O register structures are defined in other headers. The names are defined as "struct", instead of as "pointer to struct".
All but one TGI drivers didn't use IRQs. Especially when the TGI driver kernel was the only .interruptor this meant quite some unnecessary overhead because it pulled in the whole IRQ infrastructure.
The one driver using IRQs (the graphics driver for the 160x102x16 mode on the Lynx) now uses a library reference to set up a JMP to its IRQ handler.
So far conio.h included the target header to get the CH_... and COLOR_... macros. However tgi.h never did the same to get the TGI_COLOR_... macros. And some time ago the JOY_..._MASK macros moved from joystick.h into the target header yet joystick.h didn't include the target header.
Why wasn't that issue detected so far? Because about every program using TGI and/or the joystick uses CONIO too and therefore includes the target header that way.
However, conceptually it's clean to factor out the target header inclusion and have tgi.h and joystick.h do it like conio.h.
Apart from that user code may make direct use of target.h too.
All but one joystick drivers didn't use IRQs. Espsecially when the joystick driver kernel was the only .interruptor this meant quite some unnecessary overhead because it pulled in the whole IRQ infrastructure.
I was told that the one driver using IRQs (the DXS/HIT-4 Player joystick driver for the C64) can be reworked to not do it. Until this is done that driver is defunct.