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Beware file for DECmail/MS
This document reflects DECmail/MS version 10(2123)
October, 1982
0.1 Summary
DECmail/MS is a product which provides TOPS-10 and
TOPS-20 users with a sophisticated and flexible electronic
messaging capability (such capabilities are frequently
called "electronic mail"). DECmail/MS is the generic name
for a software package which includes the program MS along
with some ancillary modules which together provide a compre-
hensive multinode mail service (and, in the future, will
provide gateways to other electronic mail systems).
This document describes all bugs in this release of
DECmail/MS that were known at release time, and describes
all patches to other products required for DECmail/MS to
operate properly. It also describes any unusual conditions
or unwarranted assumptions that users and system administra-
tors should be aware of. This document should be read com-
pletely BEFORE installing DECmail/MS.
Page 2
1.0 REQUIRED PATCHES
1.1 Required Patches To TOPS10
1.1.1 Patch To TRMOP Code -
A bug in the TOPS10 terminal service causes an annoying
glitch when displaying messages on VT100s, if the SET
TEXT-SCROLL-REGION command has been given. The observed bug
is that only part of the screen will be filled, and then the
monitor will stop typing and ring the terminal bell, waiting
for the user to type ctrl-Q. This happens because the
.TOPCT TRMOP. cannot be used to set the current page
counter. To fix this bug, you need to turn on the 4000,,0
bit in word TOPTB1+24. Thus:
.R FDDT
File: /M/P
TOPTB1+24/ 30000,,653321 34000,,653321
^Z
The number in the right half shown here (653321) is used as
an example only and will be different on your system. This
patch is required only for TOPS10 versions 7.01 and 7.01A;
later monitors have this fix.
1.1.2 Patch To COMDEV For PRINT Command (7.01 And 7.01A
Only) -
The PRINT command in MS causes the named messages to be
printed on the line printer. This is done by simply opening
device LL: (or LPT:, if that fails) and copying the mes-
sages to it, presuming that by default the line printer is
spooled. For line printers attached to DN87, DN87S, or DN20
frontends, or to DN82 or DN200 remote stations, this works
fine. However, if the physical printer denoted by LL: or
LPT: is attached instead to the RSX-20F front end, MS
crashes with:
?Illegal data mode for device LPTxxx: UUO at user PC xxxxxx
This occurs because TOPS-10 reports that image mode is
legal for all line printers but those attached to the
RSX-20F front end. The following patch fixes this problem.
Page 3
In file COMDEV.MAC, change the statement:
DLPMOD==1_A+1_AL+1_BYTMOD
to:
DLPMOD==1_A+1_AL+1_BYTMOD+1_I
This patch is required only for TOPS-10 versions 7.01
and 7.01A; it is present in all later monitors.
2.0 SIZE RESTRICTIONS
2.1 User Community Size
Under TOPS-10, DECmail/MS supports AT MOST 1400 users.
Since TOPS-10 does not have the concept of a username,
DECmail/MS must simulate it. The table in which it stores
pointers to these names is 1400 words long.
Under TOPS-20, DECmail/MS supports all users of the
system. TOPS-20 currently allows around 4,000 users on an
extended-addressing machine (depending on average username
length).
2.2 Message File Size
DECmail/MS keeps the entire current message file in
core during a session. Because it does not run in extended
sections, only 256K is available for all of MS's buffers,
code, tables, and the message file. This restricts the mes-
sage file size to around 250 pages (1000 blocks). This is
true for both TOPS-10 and TOPS-20.
3.0 NEW MAILER REQUIRED FOR ADDRESS LISTS
The new address-list feature does not work when sending
mail via the old local mailer, MAILER. This means that, for
TOPS-20 systems which do not run MAILEX (the new local
mailer) or XMAILR (the Stanford/MIT internetwork mailer),
address lists will not work in mail which is entirely local.
What is meant by "not working" is that DECmail/MS will
accept the address lists, and send mail to the correct
recipients, but due to deficiencies in MAILER the received
mail will show only the recipients' names, and not the name
of the address list. If there are any network addresses in
the "To" or "cc" list, though, the address list names will
be shown, since the network mailers preserve address lists.
Page 4
The new mailer, MAILEX, is included on the DECmail/MS
distribution tape, so if you follow the installation
instructions this will not be an issue. Note that you must
continue to run the old mailer, MAILER, as well as MAILEX.
Page 5
4.0 KNOWN BUGS AND DEFICIENCIES
4.1 Nonexistent UFD's (TOPS10 Only)
DECmail/MS will not create UFD's. Under TOPS10, when a
user logs out, any empty UFD's are deleted. Since
DECmail/MS will not create UFD's, these users will be unable
to receive mail.
The simplest way around this is to create an empty file
in each UFD that is expected to receive mail. Protect this
file <777> to prevent inadvertent deletion by the user. The
existence of this file will prevent the deletion of the UFD
on logout.
4.2 GLXLIB Bugs
DECmail/MS uses a runtime library called GLXLIB which
is part of the GALAXY subsystem. This library provides many
commonly-needed functions in an operating-system-independent
manner, thus greatly simplifying the task of writing appli-
cations which will run under both TOPS-10 and TOPS-20.
Unfortunately, GLXLIB has some bugs which affect
DECmail/MS users. These bugs are documented below.
4.2.1 Message File Size Limitations (GLXMEM) -
There is a bug in GLXMEM which makes exceeding the
maximum message file size particularly painful. When a file
grows dangerously large, MS will begin warning the user,
whenever it starts up, that the file is too large and should
be pruned. When this happens the user can use the MOVE or
DELETE commands to reduce the size of the file. If the file
exceeds the maximum possible size, though, the memory
manager dies with an ASE (Addressing Space Exhausted)
stopcode. Since this requires quite a large file, however
(some 250 disk pages (TOPS-20) or 1000 blocks (TOPS-10)), MS
would have gotten quite slow about reading the file already.
This is your best indication that it is time to reduce the
size of the file. Most users find it convenient to
periodically move old messages to an archive file. This is
more for speed's sake than to avoid the file size limit,
which in fact very few users ever reach. A file of more
than 300 pages will make MS so slow that the user will be
motivated to prune it, long before the absolute maximum size
is reached.
Page 6
4.2.2 Core Limit Considerations (GLXMEM, TOPS-10 Only) -
Compared to many other TOPS-10 utilities, MS is a large
program. It typically requires 120 to 150 pages of virtual
memory. Because of a bug in GLXMEM, if a user with an
insufficient virtual memory limit tries to run MS, MS will
just go into an infinite loop. MS users should thus be
given a virtual limit of at least 150 pages and a physical
limit of at least 90 pages.
4.3 Command Scanner Bugs (GLXSCN, TOPS-10 Only)
Ordinarily enough of a command must be typed to
uniquely identify it before MS will recognize it. In order
to reduce typing for the most commonly-used commands,
though, certain special abbreviations have been defined.
For instance, R will be taken to mean READ, even though
REPLY, REPAIR, and RETRIEVE all exist.
GLXSCN is a module in GLXLIB that simulates the TOPS-20
COMND JSYS. It has the following bug related to these
abbreviations (under TOPS-10 only): you can type the
abbreviation, and MS will perform the correct action, but
recognitions will not complete the name of the command.
That is, typing R<ESC> will not cause the remainder of the
command name "EAD" to be displayed. This bug exists only
under TOPS-10.
[End of MSBWR.MEM]