====================================================
				pOS
        	   BUG/LIMITATIONS List - 12/02/2003
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	1.

	The Commodore C64 boot loader (boot) might display wrong error messages
	when failing to load the kernel image. It might state that there is a
	disk error though the floppy simply can't find the kernel image.

	This is an issue with the 1541 floppy's CBM-DOS 2.6. When trying to
	load a file with no disk inserted the floppy will produce an error
	74 (device not ready). After that the floppy produces this error
	also when the drive is ready but the file is not found. Instead
	producing error 62 (file not found) it produces 74 again. This
	can only resolved by powering the floppy off and on again.

	Example:
	1. Make sure there's no disk in the floppy
	2. LOAD"FILE",8 // FILE, a file that does not exist on the disk
	3. type this BASIC program

		1 OPEN15,8,15
		2 INPUT#15,NR
		3 PRINT NR
		4 CLOSE15
	 	RUN

	   the computer will answer "74"
	4. Insert any formatted disk and
	   reproduce steps 1 to 3, the computer
	   will still answer "74" instead "62"

	This has been fixed with CBM-DOS 3.0 on the VC-1571 floppy
	drive. But the 1571 must be in C128 mode otherwise it will
	behave like a 1541-I/II including their bugs.

	2.

	in include/asm-c64/schedule.h:

	m_saveenv

	this routine cannot handle stacks larger than
	128 bytes due to the fact that it uses the
	"branch if plus"-condition in the stack-save
	loop: the loop aborts when the negative flag
	is set, this happens both when decrementing
	a zero value to -1 or when the value is larger than
	127 (127 = 01111111, 128 (unsigned) = 10000000
	= -128 (signed))

	3.

	free (remalloc) does not accept "wild" pointer values within
	a memory block. But it often occurs that a pointer is incremented
	or decremented. The free function will then need to jump from
	memory block to memory block to find the block the pointer
	belongs to. But I don't	know whether this feature is in line
	with other OS designs, does Linux free accept wild pointers ?

	4.

	The filesystem-driver for the 1541-filesystem does not comply
	to the kernels filesystem layer-architecture. Actually it does
	not manage a filesystem on a blockdevice over a block-
	device-driver as determined by the original layer-design.
	Instead it communicates with the 1541-floppy directly
	using conventional commands like the LOAD/SAVE-routines
	in the C64-ROM-KERNAL do and have the 1541-ROM-DOS manage
	the filesystem. This break-up of the system-design was
	chosen intentionally and is implemented for speed-issues,
	to reduce implementation-work and possible bugs. This
	way the filesystem-driver still appears as a normal filesystem-
	driver to the system with the interface required by the
	system-design. Once the kernel has reached a more
	advanced development status this 1541-filesystem-driver
	will be dropped and replaced with a proper driver
	possibly with a native filesystem providing more
	functionality.