	[312,315] SPRING 1980 COLLECTION

	This collection includes a revision to DDT22 to fix some
bugs in the Fall '79 version and the MSX operating system plus a couple
of utilities.
	The DDT22 source, DDT22.MAC, should be assembled. All of the PDP11
address space may be accessed if the DDT has access to the I/O page, and
tasks may be examined even where they are too big to include DDT by making
DDT a separate task. Under IAS, you must set the PARs yourself to map the
task; under RSX11M you may type a command to get DDT to find the mapping.
In either, for this mode, you must ensure the task being examined or modified
is not moved or checkpointed. As a normal debugger, DDT gives symbolic
capabilities in addition to everything ODT can do.
	MSX-11 is a distributed operating system for coupled PDP11 processors
(11/23 or above), or it may be an emulator of a network, running several
copies of MSX under RSX11M (or IAS with reduced capabilities) with each
copy acting as a virtual CPU. Each CPU is multiprogrammed and the tasks
running under MSX work alike in emulation or under the real stand-alone
MSX (with a few exceptions in interrupt simulation which will normally
be used only by operating system emulators running under MSX, and a few
mapping differences). Full sources are provided, and MSX is typically
built with DDT (and the stand alone version uses DDT as a system debugger).
	A couple of utilities are here. DSKFIX is a disk block patcher.
RCONEW is a version of Ray French's locked-file recovery program. FLDMOV
allows you to move a field of any number of bits from any location (starting
at any bit counting from the left in any word) to any other location. It is
FORTRAN callable and useful where data is to be packed or unpacked.
	A revised version of RSX FOCAL is included also, to provide minor
corrections to the version from San Francisco, 1978.
	VDDRV, VDPRV, and VDKDRV are virtual disk drivers for IAS or
RSX11D. VDDRV allows encrypted virtual volumes; VDKDRV may be built to
simply allow virtual unencrypted disks (it is a subset of VDDRV but
does not ask for cipher keys whenever loaded.) The files need not be
contiguous, and do NOT install tasks on a virtual disk. Other than
that, the virtual disk will allow unmodified software to use encrypted
data bases by reassigning its LUNs, and provide a measure of data
security unavailable under straight FILES-11.
