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-*- Text -*-

General:

	Is uio.h old hat?  But isn't this the file that you include to
	declare open()?
[KLH: Yes, flush uio.h.  Nothing should still use it.  Did you find something
that does?]

	Not doing anything about O_NDELAY and other blocking issues yet.

	Some code in read() and write() is the only thing that currently
	thinks about system calls being interrupted in the brain-damaged
	Unix way.  There is no support for the signal stuff, but the idea
	is that we have to cause certain SYSCALLn's to return with a
	negative value.

	It looks like we will need a %PIIOC handler that makes certain IOC
	errors look like failing .CALL's.  (If the losing PC is .SCALL+2,
	clobber the error code into AC1 and dismiss to .SCALL+3.)

	Rubout processing isn't finished.  Nor has anything else
	TTY-related been worked on.

	There are a lot of other little details to be done, and no obvious
	organized way to go about it.

Compiler:

	ERJMP definitions are output even for ITS.
[KLH: OK, fixed.]
	ADJBP macro output for KA is incorrect.
[KLH: if you meant AC and MEM dummy args, this was already fixed.]

LSEEK:

	On block mode output (_UIO_HANDPACK is set) you can only position
	from one word boundary to another.  Doesn't know how to do L_XTND.
	(Usual EOF screw.)  ITS won't let you do any operations if you
	position yourself beyond the end of the file anyway.

[KLH: hmm, should be able to position at byte boundaries.  This can be
fixed, right?]

USYSIO.H:

	_UIO_HANDPACK indicates block mode open so we must pack and unpack
	bytes by hand.  Introduced OPEN_UFX_MAX as distinct from OPEN_MAX.
	There are only 16 ufxs on ITS, each corresponding to a channel.

OPEN:

	O_ITS_IMAGE and O_ITS_NO_IMAGE are new.  Byte size of 7 implies
	ascii mode, all others imply image mode, unless these flags are
	used to force the issue.  Also byte size of 7 implies unit mode,
	all others imply block (handpacked) mode.

	Should support append mode.  (How?  No reasonable way to find the
	end of a file...)  Also overwrite?  (Can't truncate!)
[KLH: don't worry about truncation, that's rarely used.  append is
a lot more common, tho.  Time to play with ITS?]

	Filenames are hacked in a number of ways.  "/" is a synonym for
	";", for the benefit of #include.  (In ITS.1617 SOPEN will parse
	"foo; bar;" as "FOO.BA;".)  Tab is a synonym for " " because people
	expect it.  ^Q quotes the next character as usual.

	_DVTTY minor device number initialization in open() is commented
	out right now.  close() will therefore do something random, but
	harmless.

FREOPE:

	"I" and "I-" added, corresponding to flags above.

FCNTL.H:

	FDF_HANDPACK = _UIO_HANDPACK

MALLOC:

	Removed test for extended addressing and call to EXTEND [XBLT] on
	ITS (mostly) because FAIL didn't have XBLT predefined.

[KLH: KCC includes a definition of XBLT in its header.]

	There is a bug in _setup() that touches nonexistent memory.  I did
	not fix it, because the temptation to re-write the entire MALLOC
	module would be too great.  Instead I broke brk() to always keep at
	least 4 extra words existent so that I wouldn't have to think about
	problems like this unless they were really bad ones.

SIGDAT:

	_sigtrigpend() is just a stub.  Should never get called until we do
	something about interrupts.

WAIT:

	wait() is just a stub.  Should never get called since we don't hack
	inferiors (yet?).

STAT:

	stat(), fstat(), etc., don't work.  The file currently only exists
	to define _dvtype().

SYSCAL:
SYSITS.H:

	SYSCALLn("name") performs system call.
	SYSCALLn_LOSE("name") performs system call that should not fail.

STRERR:

	This doesn't do anything yet.  Nedds to be converted to use ERR:
	device someday.

ERRNO.H:

	Shouldn't _ERRNO_T20_LAST be ECLOSE?
[KLH: yeah, fixed.]
	What do we do about ITS error codes?  Add 400000?
[KLH: that would be OK.  There isn't any good way to combine Unix error
numbers with OS errors.  Having strerror recognize OS numbers is an
extension, but the actual strerror call in this case has to be conditionalized.
An argument of -1 (another extension) gets the last OS error; this lets me
define LASTERROR to be either "errno" (on a real Unix) or "-1" (for KCC)]

STDIO.H:

	On ITS SYS_OPEN is 16.  Should perhaps set L_cuserid to 6?

EXIT:

	The reasons for waiting for a subfork are different on ITS?

URT:

	Command line starts with XJNAME.  ^Q instead of ^V.

CRT:

	Initialization of P is wrong everywhere but ITS.
	Enabled %PIPDL interrupt to make it fatal.
	Had to create pages of zeros in the data segment that the linker
		left nonexistent.
	Set code segment pages pure.
	Set %TBNVR so that opening the TTY will fail rather than hanging
		forever if we are started without it.  (This does have the
		odd effect that if we are ^Ped during startup we never open
		the TTY.  It is a deficiency in ITS that you cannot open
		the TTY without owning it.  We could compensate for this
		ourselves someday.)

CPU:

	FAIL can't assemble this because $BADL6, $BADL7, $BADL8, $BADL9,
	$BADLH are EXTERNals after ==.

[KLH: Right.  Use MACRO for that.  We use MACRO for most of the library.]