SYSOP NOTES FOR ABBS
--------------------
Congratulations! You are now about to become a Computer Bulletin
Board System (CBBS) Operator. As System Operator (SYSOP), you will be
responsible for maintaining a useful and informative service for your
club, your organization, your friends, or the general public.
This program is called an Apple Bulletin Board System (ABBS), since
it is a CBBS that runs on an Apple ][. As to hardware, you will need:
An Apple ][+ computer (or an Apple ][ with Applesoft on a ROMCARD or
on a 16K Card);
Two standard Apple (or compatible) 5 1/4" disk drives running under
DOS 3.3;
A D.C. Hayes Micromodem II in slot 3 (you may move it to slot 2 after
making certain changes in the program);
The two disks containing this file, the WAPABBS program and sample
files ready for your own adaptation;
A viewing device such as a monitor, CRT, or TV set that will allow
you to see what the ABBS is doing;
A text editor for the addition, deletion and maintenance of the text
files that the ABBS uses. The DOS Tool Kit, sold by Apple Computer, is
adequate for your needs; a word processing program that uses text files
will probably also work. Many Apple users' groups have excellent text
editors in their program libraries;
A Mountain Hardware CPS Multifunction Card in slot 4 (this is
optional -- the ABBS will work without the clock card, but you must change
the date manually);
A printer to print out listings and preserve a record of messages
(this is optional also). In order for the printer to record what the ABBS
is doing while in operation, you must have a printer that uses an Apple
parallel interface card in slot 1 or is otherwise able to print out a
character POKEd to $C090; and
Additionally, you will want to give serious consideration to giving
the ABBS its own private telephone line. No matter what times you tell
your users that your system is up, they will call in at all hours of the
day or night.
This is not a "turnkey" system. In order to run an ABBS effectively,
you will need to know BASIC reasonably well. It would not hurt to know
some assembly language. You should either know or expect to acquire by
experience some knowledge of modems. You should have the Apple and
Micromodem II manuals; try also to obtain a copy of manuals for the
Novation Apple Cat II and the D.C. Hayes Smartmodem because people with
these popular modems will probably ask you how to use the ABBS with them.
This program is copyright (1982) by Thomas S. Warrick. Sale of these
programs for any price more than a nominal amount in excess of the value
of the media is prohibited without express permission of the copyright
holders. (In other words, you can't sell a copy of anything on these
disks for a profit.)
THE FILES ON THESE DISKS:
The files on these disks are designed to run in specific disk
drives. In drive 1 should be the disk with these files:
WAPABBS -- This is the ABBS program. Disk 1 will run this program on
boot-up so that if your system suffers a temporary power outage the system
will restart itself. This program will be described in great detail
below.
ABBS1.OBJ0 -- This binary file contains the input/output routines and
the "&" routines, which handle the message summary strings. To run the
ABBS with your Micromodem in slot 2, change one of the first line numbers
in the program's source code (on disk 2) and re-assemble it. (You will
also have to change line 10 of WAPABBS to set SL = 2.)
ABBS3.OBJ0 -- This binary file loads several machine language
routines into page 3. Most important is the line input routine, which
begins at 768 ($300). The source file, ABBS3, is on disk 2.
STARTUP -- This text file contains 5 entries: today's date (in a
special form discussed below in connection with field 3 of the MESSAGES
file), the date of the last bulletin, the password for uploading files to
the ABBS, the userid (pronounced YOU-zer-eye-dee, this string is used to
identify a person, such as WAP001 or WP2027) for a person other than the
SYSOP who is allowed to change the date, and the userid for a person other
than the SYSOP who is allowed to change the date and to look at the
password file. Note that if you have the CPS card, you will not need to
worry about setting the date (except for the bulletin date). These will
be discussed more below.
MESSAGES -- This is the principal file to which your users will be
reading and writing; thus, it is first on the disk in order to make disk
access as fast as possible. Understanding the structure of Messages is
very important to an understanding of WAPABBS. Messages is a
random-access text file with a record length of 452 characters. The file
is initialized with 138 "EMPTY " records. When a message is in use, it
consists of up to 14 fields, each followed by a return:
The userid of the sender (6 characters);
The userid of the recipient (6 characters);
The date of the message (13 characters in the form YYMMDD.HHMMSS,
where YY=year, MM=month, DD=day, HH=hour, MM=minute, SS=second; this is
the format for the date that must always be used in the STARTUP file)
A summary of the message (20 characters); and
The text of the message in up to 10 lines of up to 39 characters
each. If the message is less than 10 lines, the last line of text is
followed by a null line, i.e., a line with no characters prior to the
return that ends the line.
USERS -- This text file contains 40-character records with this
information:
characters 1-4: The numeric portion of the userid, in 4-digit
form. Thus user 1 is "0001"; user 2027 is "2027";
characters 5-8: The password;
characters 9-23: The user's name with last name first;
characters 24-33: The last date the user called in, in the form
YYMMDD.HHX, where X is 1/10ths of an hour. This is the maximum precision
of Applesoft;
characters 34-37: The number of times the user has signed on;
character 38: The letter "N". This character is available for
manipulation; you may, for example, use this character to record whether
or not someone has answered the Opinion question;
character 39: The "!" character. This is used to make a border on
printouts of the file. It is also available for manipulation by your own
revisions of WAPABBS; and
character 40: A carriage return.
Note that after the return that ends the last user record there must be
another return to signify the end of the file. The text editor you use to
add or change passwords should be able to show you the length of this
file. It must always be 1 greater than a number evenly divisible by 40
(e.g., 41 or 3961) in order for WAPABBS to work. WAPABBS accesses this
file as a random-access file in order to check the passwords of users when
they sign on, but as a sequential text file when printing out a list of
passwords in response to a several command.
USERS.OBJ -- This binary file allows the USERS file to contain
non-sequential userid numbers. Each location contains 255 ($FF) if the
user is allowed on the system and 0 if the user is not allowed on the
system. Thus where the USERS file begins with user numbers 0001, 0002,
0004, 0006 and 0008, USERS.OBJ would begin $FF $FF $00 $FF $00 $FF $00
$FF. USERS.OBJ is loaded into memory at $8400 and is $1000 (4096
decimal) bytes long; the first userid, 0001, is stored at $8401 and thus
WAPABBS can have userid numbers up to 4095. An Applesoft program on disk
2, BUILD USERS.OBJ, allows you to update this file after you change the
USERS file.
BULLETIN -- This text file is your way of communicating to all users
any new information about the system, yourself, your club, or anything
else. Everyone who signs on will be asked whether they want to read the
bulletin before proceeding further. The bulletin is a sequential text
file, and -- as with virtually all such files used by WAPABBS -- the last
line entered must be a null line in order for the program to work
properly. To keep your users' interest, you should change the bulletin at
least weekly.
BBS -- This sequential text file gives phone numbers and other
information of other CBBS systems in your area. Asterisks have been added
as a border for esthetic purposes. This file also ends with a null line.
MEETINGS -- This sequential text file gives the dates, times and
places of meetings of potential interest to your users. As this file
comes to you, it gives the meeting information for Washington Apple
Pi. This file also ends with a null line.
CLUB STORE -- This sequential text file provides information about
any quasi-commercial ventures you, your organization, or anybody else may
have. If you don't have any such activity, you may want to use this file
as a "Shopper's Guide" to products, services and stores in your
area. This file also ends with a null line.
In drive 2 should be the disk with these files:
INSTRUCTIONS -- This sequential text file gives instructions in the
use of the ABBS to your new users. You should read these carefully. This
file also ends with a null line. Insert your name in the file where
appropriate.
BUILD USERS.OBJ -- This Applesoft program should be run every time
you add or delete an entry to or from the USERS file. It looks at each
record in the file and builds the USERS.OBJ file according to whether a
particular userid is listed in the USERS file. BUILD USERS.OBJ then runs
WAPABBS to restart the system.
TO SYSOP -- This sequential text file stores messages left to you by
up to 9 people who do not have passwords. The first entry in the file is
a one-digit number of the number of messages in the file. The text of the
messages follows. This file may be retrieved only by you.
UPLOAD1 -- This sequential text file gives the instructions for
uploading and downloading files from the ABBS. "Uploading" means sending
files from other computers to the ABBS; "downloading" means sending files
from the ABBS to other computers.
UPLOAD2 -- This sequential text file contains a list of files
available for uploading. A null line terminates the listing; this is
necessary so that uploads will adjust this file properly.
OPINION -- This sequential text file has as its first record a
question to which everyone can respond. Answers are stored right after
the question. Only you can see the answers, however. No check is made to
see whether someone has answered more than once.
REMEMBER II -- This text file is available for downloading. You
should EXEC it with MON I in effect, and BSAVE it as it says. This is, if
I may say, an excellent terminal program for the Micromodem
II. Non-commercial distribution is permitted, and this program may not be
sold without express permission of Washington Apple Pi.
REM II INSTRUCTIONS -- This text file contains the instructions for
REMEMBER II. You should EXEC it in the same manner to create a file
called REM II.OBJ1, which REMEMBER II will access when you request
instructions in its use.
ABBS1 and ABBS3 are source code for the binary files discussed above.
AN ANALYSIS OF THE PROGRAMS:
I. THE INPUT/OUTPUT ROUTINES
ABBS1.OBJ0 handles I/O for WAPABBS. The I/O routines are activated
by a "CALL 37888" in line 32 of WAPABBS. This routine changes the CSW/KSW
vectors ($36-$39) to the ABBS's I/O routines, sets the "&" vector
($3F5-$3F7), and jumps to the DOS routine that reconnects DOS's I/O hooks.
The Output routine, which begins at $9420, first does a test to see
if the character being output is lowercase. If so, the character is
EOR'ed against LOCSE. If lowercase-to-uppercase conversion is on, LOCSE
is set to $20; if off, it is $00. Following this, the accumulator
(hereafter referred to as "A") and the X and Y registers are saved on the
stack.
Next, the keyboard is checked for an interrupt character such as
ctrl-C. Since only the SYSOP can enter a key from the ABBS's Apple, this
is given priority. If a key was not pressed, the Receiver Register Full
bit is checked to see if an interrupt character has arrived through the
modem. If not, the character in the accumulator is sent out through the
modem, the A, X, and Y registers are restored, and the character is
printed on the ABBS's computer's monitor in uppercase form.
If a character was entered at the keyboard or from the modem while
output was in process, several tests are made. If the character was a
ctrl-S, the program waits for another character to be received or entered
before resuming output. Next, CKMASK is checked to see if a ctrl-C or
ctrl-K is allowed. If either is allowed (i.e., if CKMASK = 0) and if the
character received is indeed a ctrl-C or ctrl-K, the program clears the
stack and jumps to Applesoft line 2000. If the character received was
neither a ctrl-C nor a ctrl-K, it is ignored and the character is sent out
anyway.
The input routine, which begins at $9488, first saves the X register,
which is the offset from $200 (the start of the input buffer), into CLL,
"Current Line Length." X is also saved on the stack and tested against
LINEMAX. This prevents the user from entering a line longer than WAPABBS
is expecting. If the line is too long, the user is sent a bell (ctrl-G).
After saving Y on the stack, WAPABBS checks ACTIVE ($E3). If ACTIVE
>= 128, the ABBS hangs up the phone, clears the stack, and jumps to
Applesoft line 1000. Next, the timer is reset to 0 unless WAPABBS is
awaiting a call (ACTIVE=0). The timer is discussed in detail below.
If the ABBS is awaiting a call, the standard Micromodem input routine
is used. This routine returns only when a call is answered. If carrier
is detected -- which would not be the case if a human had dialled the ABBS
by mistake -- ACTIVE is set to 2, the X and Y registers are restored, and
the input routine is concluded. If carrier is not detected, ACTIVE is
unchanged, and the next request for input will continue to await a call.
The next sequence of code hangs up the phone, using the Micromodem
routine at $CAB5. ACTIVE is reset to 0, LOCSE is set to $20 so that
lowercase characters will be translated to uppercase for the next caller,
the stack is cleared, and control falls into the GOTO routine.
The GOTO routine, at $94D0, immediately outputs a return to clear any
active input lines and outputs a ctrl-D followed by a return to terminate
any active DOS commands. The line number passed to GOTO in the A,Y
registers is used to set Applesoft's TXTPTR vector ($B8-$B9), the stack is
cleared, and execution of the appropriate Applesoft line number begins.
The HANG routine, at $94FB, forces the ABBS's Apple to freeze up if
program execution terminates for any reason. This prevents anyone from
getting "inside" your computer. You will see a flashing "$33" if this
routine has been triggered. Ctrl-C will return you to BASIC.
The regular input routine resumes at $951B. The timer is incremented
by one. This timer will automatically hang up the phone if no one has
entered a character for 7 minutes, 8 seconds. This prevents someone from
tying up the ABBS by leaving their computer connected inadvertently.
If bit 6 of ACTIVE is set, the ABBS will ignore the modem. This is
so that when you want to use the ABBS yourself, WAPABBS will not answer
the phone. Thus if ACTIVE=64, no modem input is recognized.
If modem input is allowed, the modem is checked to see if the user's
modem's carrier tone has been lost. If it has, WAPABBS hangs up the
phone. If not, the modem is polled for data. If a character has arrived,
the most significant bit is set and processing begins. If no data has
arrived from the modem, the keyboard is checked. If a ctrl-A has been
pressed by the SYSOP, WAPABBS responds:
MM II:
You may now enter these characters with these results:
ctrl-Z Hangs up on the user
ctrl-B Begins Chat mode by doing a jump to 4300
ctrl-I Flashes an "I" on the screen, meaning that the SYSOP is now "in"
ctrl-O Flashes an "O" on the screen, meaning that the SYSOP is now
"out"
ctrl-R Sends a ctrl-R out over the modem
ctrl-T Sends a ctrl-T out over the modem
ctrl-U (right-arrow) Prints the userid of the current user (or the most
recent user if no one is on the ABBS at the moment)
Otherwise, the character is ignored and input resumes. Note that anything
sent by the user during the interval between the ctrl-A and the next
character is neither received nor echoed.
If a character has been received, the ABBS's screen is set to
non-flashing, which is Apple convention to let you know that a character
has been received.
If a rubout has been received (ASCII $7F), the user is sent a bell
and the character is ignored. If carrier has been lost, WAPABBS hangs up
the phone. If a parity error, receiver overrun error, or framing error is
detected, the character is ignored. The user will notice that his
character was not echoed.
At this point, FLAGS is checked to ensure that DISPO, TRAN and KBDE
are always set. (See the Micromodem manual.) Unpleasant results would
ensue if one of these bits was cleared by static electricity or a cosmic
ray.
If the character is lowercase and lowercase is not allowed by the
ABBS, it is converted to uppercase. The most significant bit of a
lowercase character must be cleared in order to fool the Apple's System
Monitor.
Finally, the character that was received is checked to see if it is a
control character. If not, LINEMAX is checked, and if the character would
make the line too long, the character is ignored with a beep. If line
length is acceptable, the X and Y registers are restored and the character
is loaded into the accumulator, printed out through $C010, and the input
routine is concluded.
If the character is a control character, special handling may be
required. A carriage return is treated normally. A backspace is ignored
with a beep if you backspace before you have entered anything that could
be backspaced-over. A backspace is sent out over the modem as a
backspace, a blank space, and another backspace. This erases the
character from the user's screen, but not from the screen of the ABBS.
A ctrl-U (the right-arrow) picks up the current character from the
ABBS's screen and treats that as the input character. This allows users
to retrieve previously-erased characters.
The ABBS next checks to see if a ctrl-C or a ctrl-K is permitted. If
so, and if the character is a ctrl-C or a ctrl-K, it is treated in the
same manner as ctrl-C or ctrl-K were by the output routine.
A linefeed (ctrl-J) turns on LFI (see the Micromodem manual) which
will send linefeeds after each carriage return. This affects modem
output, not screen output.
A ctrl-X acts exactly as ctrl-X does on regular Apple input: it
cancels the input line and asks for another one. X and CLL are returned
to the left margin, i.e., zero.
Ctrl-L toggles LOCSE, which allows lowercase input. Ctrl-L has the
function of a shift-lock key.
The short routines that follow handle the ignore-this-character
routine and the cursor.
The next group of routines handle the ampersand ("&"). These
routines manipulate the message summary strings, which begin at
$6B00. These strings would require more than 1K of overhead if handled as
traditional Applesoft strings.
1. Assign a string to the message summary array:
& A J,K,A$
where A means "assign", J is the message number, K is which part of the
message summary the string is to be stored (0=the user the message is
from, 1=the user the message is to, 2=the date, and 3=the summary of the
text of the message), and A$ is the string to move into the message
summary array.
2. Print a string:
& P J,K
where P means "print", and J and K have the same meaning as above.
3. Assign one of the elements of the array to B$:
& B J,K
where B means "LET B$ = ", and J and K have the same meaning as in string
assignment. Note that only the variable B$ can be used in this
manner. Furthermore, B$ must already have been set equal to something by
an earlier program line or direct command such as: B$ = "HELLO"
4. Test an element of the message summary array:
& T J,K,A$,L
where T means "test", J and K have their usual meaning, A$ refers to the
string being tested against the message summary item, and L is the
variable used to store the result. The result will be:
1 if message summary item > A$
0 if message summary item = A$
-1 if message summary item < A$
II. THE PAGE 3 ROUTINES
ABBS3.OBJ0 has three routines. The first, called INLIN, is a
revision of the well-known "Input Anything" routine. This modification,
however, uses this syntax:
CALL INLIN [,X]
where INLIN=768 and X is the maximum allowable line length (LINEMAX). If
X is not specified, the previous maximum line length is used. X must be
between 0 and 255; note that if X>248, both you and the user will hear
beeps after the entry of the 249th through 255th character. In order for
INLIN to work, the first variable in the main Applesoft program must be a
character string; WAPABBS uses A$. The routine accepts commas, colons,
and quotation marks; only a return will terminate input. The routine ends
by setting A$ equal to what was just entered, but A$ is still in the input
buffer and will be written over by the next input request or by the next
DOS command. To save the string, you must use the command:
A$ = MID$ (A$,1)
Note that a simple assignment statement such as B$ = A$ will not work.
The next routine does an index function:
CALL 804,A$,B$,J
This looks for the first character of A$ in the string B$, and returns
with J equal to the relative position of the first occurrence of the
character. So if A$="HELLO" and B$="ABCDEFGHIGHHH", J would become 8. If
"H" did not occur in B$, J would be set to 0.
The third routine looks up the userid number and calculates the
record number in the USERS sequential text file. Its syntax is:
CALL 892,J
where J is the userid number. J is returned as the record number. For
example, if user WAP538 calls in, J would be set by a WAPABBS routine to
538. This routine would go through the USERS.OBJ file in memory and would
calculate how many userid numbers between 1 and 538 were "active." The
result would be the record number of user 538's password entry in the
USERS file. If user 538 were not on the system, J would become 0. Note
that this routine is used in the signon process and in the W and Y
commands.
III. VARIABLES USED IN WAPABBS
A$ must be the first variable used in the program in order for the
machine language routine at $300 to work. A$ is the workhorse string
variable; all string input passes through A$. Note that if A$ has been
set by the routine at $300, for so long as A$ is not assigned to another
variable, A$ will not take up regular memory space and will not create
"garbage."
ACTIVE is a flag used to tell the I/O routines whether the SYSOP, a
user, or no one is currently using the ABBS. See above for a further
description of the values ACTIVE can have.
AC$ [Allowable Commands] is a list of the letters of allowable
commands. CALL 804 uses this to compute the index value of the response
to the "COMMAND?" prompt for use by the ON J GOTO in line 2011. The CALL
804 routine requires that AC$ be a variable.
AL$ is "ALL ", and is used by the message handling routines to
prevent errors that would occur if a user entered "ALL", which is only 3
characters long, instead of the 6-character response that the ABBS
expected.
B$ is the secondary string variable. It is used by the "&" message
summary routines and for other general purposes.
BD$ [Bulletin Date] is a 4-character string that tells users when the
bulletin was most recently updated.
B(6) is an array used by the sorting routine that organizes the
messages into date order.
C80 is 1 if the user has selected 80-column mode with the
"+" command, 0 otherwise.
CH [CHat] is 1 if you have indicated your availability for a chat, 0
otherwise. See the description of the ABBS1 routines and program lines
1010 and 1020.
CK [CKmask] is 0 if the user is permitted to interrupt program
execution and return to the "COMMAND?" prompt; 1 means interruption is not
permitted.
CM$ is a comma (","). This must be a variable so that the CALL 804
routine can tell whether what should have been a file name has a comma.
CRDLY is the delay (in 0.1 seconds) sent after each carriage return
if the user has specified linefeed insertion. This is the standard
Micromodem delay. Note that setting this to 0 is equivalent to specifying
a delay of 2.56 seconds.
D$ is ctrl-D.
D1$ [Date1] is "> " and is used to create a date value higher
than any valid date. In this way, WAPABBS will sort the messages in
proper date order.
DA$ [DAte] is the current date as specified in the STARTUP file or by
the clock.
DA(MS) [DAte order; see below for meaning of MS] is used to store the
messages in date order. DA(1) is equal to the message number of the
oldest message, DA(2) is the number of the second oldest, etc.
DR [DRive] is a location within DOS 3.3 that, when poked with 1 or 2,
will access that disk drive for the next DOS command without requiring
",D1" or ",D2".
E$ contains "E" and is used by CALL 804 to check that a number
entered was not in exponential notation.
EM$ [Empty] contains "EMPTY ", and is used to erase the "From" value
in message summaries and on disk.
ER [ERror] is used to store error codes. Certain errors are ignored,
some are processed, and some stop program execution. See the description
of the lines of WAPABBS beginning with 40000.
F [File number] is used to store the number of the file being
accessed.
FC$ contains ctrl-D + "CLOSE". When printed, this will close all
disk files.
FG [FlaGging messagesg] is 1 if, when reviewing message summaries,
the user has chosen to flag those messages he wishes to read in full. It
is 0 if the user has chosen not to be asked whether he will read the full
text of certain messages.
FG(MS) [FlaGged messages; see below for MS] contains a 1 in an
element if that message has been flagged for a reading of its complete
text, and a 0 if the message has not been flagged.
FLAGS is the location of the Micromodem's FLAGS byte. See the
Micromodem manual for complete details.
FO$ contains ctrl-D + "OPEN".
FP$ contains ctrl-D + "POSITION".
FR$ contains ctrl-D + "READ".
FW$ contains ctrl-D + "WRITE".
F$(12) contains the 12 file names used by WAPABBS.
INLIN is 768. This is the address of the line input routine
beginning at $300.
J is the workhorse numeric variable. It is often the message number
being printed or processed or an index in a FOR-NEXT loop.
JJ is a secondary general-purpose numeric variable.
K is the second most-commonly used numeric variable. It is often a
line counter, used to make sure that message lengths are no more than 10
lines long.
KK is another secondary general-purpose numeric variable.
KU [Knowledgeable User] is 1 if the user claims to be familiar with
the operations of the ABBS, 0 otherwise. If KU = 1, many prompts are
shortened or eliminated.
L [Logical variable] is usually used as the result of a logical test
of a message summary string using the &T function. It is usually -1, 0,
or +1.
LC [Last Call] holds the date and time (to the nearest 0.1 hour) that
the user last called in to the ABBS.
MC [Message Count] is the number of messages currently in use. Given
the way DA(MS) works, DA(MC) is the message number of the most-recently
entered message and DA(MC+1) is the message number of the most
recently-deleted message and will become the message number assigned to
the next-entered message. Think about this for a while.
MI$ is ctrl-D + "MON I". All files are printed out with MON I in
effect because this is fast and causes no unnecessary interruptions
between lines.
MO(12) contains the number of days in each month. Change this during
leap years!
MS is the total number of messages that the system will allow. The
two constraints to increasing this are disk space and space in the message
summary area. Many arrays are dimensioned by MS.
M$(13) is used to enter and edit messages. M$(0) has the userid of
the sender of the message, M$(1) has the userid of the recipient,
M$(2) has the date the message was entered, M$(3) has the message summary,
and M$(4)-M$(13) store the lines of the text of the message.
NM$ is ctrl-D + "NOMON C,I,O". See MI$ for an explanation of why
this is necessary.
R [Record number] is used by the random-access file routines to
select the message number to be read or written.
S1$ [Sysop1] has the SYSOP's userid in 4-digit numeric form. If the
SYSOP's number were WAP001, for example, S1$ should be set to
"0001". This is necessary to keep the "Y" routine from printing the
SYSOP's password.
SL [SLot] contains the Micromodem's slot number.
SO [SignOns] contains the number of users who have successfully
signed on. If someone signs on more than once, they are counted more than
once.
SY$ [SYSOP] contains the userid of the SYSOP. Observe when going
through the program listing that the SYSOP can do many things forbidden to
others.
T1$ [T user 1] is the userid of a person who is able to change the
date if you are unable to do so.
T2$ [T user 2] is the userid of the person who can change the date
and print the password file. If you have no one to whom you want to allow
access to the date or password file, set these to your own userid to
prevent anyone from having this much access.
U$ [Userid] is the userid of the user currently on the ABBS. In case
you have not guessed, a userid is a 6-character string with a 2 or 3
letter prefix and a numeric suffix in the range 1-4095.
UL$ [UpLoad] contains the letters of the four commands allowed during
uploads.
UP$ [UPload] is the password necessary to begin uploading a file into
the ABBS.
Z is a general-purpose numeric variable.
ble.