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[ THE KAY*FOG RBBS | CPM-CC03.ART | posted 01/18/86 | 492 lines 24k ]
The CP/M Connection Originally published in
by Computer Currents
Ted Silveira 2550 9th Street
(copyright and all rights reserved) Berkeley, CA 94710
April 9, 1985
FINDING YOUR WAY AROUND AN RCP/M
If you want to get a lot of public domain software quickly, your best
bet is to pillage the library of a local users' group--there you can fill
up disk after disk, usually for free. But if you want to find the newest,
the best, and the rarest, you need to haunt the computer bulletin boards.
In the CP/M world, a bulletin board may be called an RBBS (Remote
Bulletin Board System), a CBBS (Computer Bulletin Board System), or just a
BBS. But most often, a bulletin board that has public domain software is
called an RCP/M, a Remote CP/M system. That title is misleading these
days, as most RCP/Ms also have public domain software for IBM PC and MS/DOS
computers.
RCP/Ms can be exciting places (hundreds of programs, dozens of
commands) but also confusing ones (dozens of commands, hundreds of
programs). So, for those of you who are new to the game, I'm going put off
reviewing public domain software for a moment and show you around a typical
RCP/M. To get started, you need your computer, a phone line, a modem to
allow your computer to transmit over the phone line, and a modem program to
control all this hardware. The modem program should be one that can use
the XMODEM protocol, like MEX112, MDM740, and the other programs I covered
last issue.
GET READY
Here's a final checklist before you make your call. You have your
computer hooked to your modem, and your modem hooked to the phone line.
You have a modem program ready to run, and you know the whole combination
works. You also have the phone numbers of some local RCP/Ms (if not, look
at the "Networks and User Groups" section in the back of Computer
Currents).
Get the documentation for your modem and modem program and before
calling, review the procedures for
--dialing a call,
--making a connection when the RCP/M answers (most modems now handle
this automatically, but some don't),
--getting from command mode (where you give instructions to your modem
program) to terminal mode (where you talk to the RCP/M) and back again,
--capturing the data from your screen into a disk file,
--and receiving files by the XMODEM protocol.
Keep this documentation nearby during your calls.
Make sure you have at least 100K of free disk space, either on the
disk that holds your modem program or on a blank disk an another drive.
You may think that's excessive, but you'll fill it sooner than you think,
especially if you have a high speed modem.
Place a notepad and pencil nearby to write down instructions, numbers
of messages you want to read, and so forth.
GET SET
Start up your modem program, and set your transmission speed (called
the baud rate, roughly equal to bits-per-second). If you have a high speed
modem that can run at 1200 (or even 2400) baud, make sure the RCP/M you're
calling can handle that speed. If you're not sure, call at 300 baud first.
You must also be sending and receiving data in the proper format for
an RCP/M--1 start bit, 8 data bits, no parity, 1 stop bit. This format is
so common that almost all public domain and commercial modem programs use
it as the default setting.
Following your modem program's instructions, open a disk file to
capture your coming RCP/M session into a disk file. Later, you can print
the file and look it over at your leisure.
GO
Dial the phone number. It will probably be busy. But if you're
lucky, the phone will ring, and the computer at the other end will answer.
If the phone rings more than three times, it usually means the RCP/M is
down (not working), either temporarily or permanently. If the RCP/M
answers the phone, its modem will give a high-pitched whistle. Your modem
will answer, either automatically or at your urging, with a whistle of its
own and make the connection. Even if you can't hear the process, your
modem program should tell you when you're connected.
Once you're connected, hit several carriage returns quickly, so that
the RCP/M can lock on to your speed. Usually the RCP/M responds after just
two or three carriage returns, but some take about 15 seconds to wake up.
If you get no response after 15 seconds, there's a problem at the other
end; hang up and try another system. If the RCP/M does respond, your sign-
on will begin.
THE SIGN-ON
First, the RCP/M will probably ask, "How many nulls do you need (0-
9)?" If you're using a computer to call this RCP/M, answer 0 (zero). The
nulls add a delay to the end of each line so that slow teletype terminals
can do their carriage return. Computers are so fast that they don't
require any delay, but if you find you're losing characters at the
beginning of each line, increase the number of nulls. (I've never had to.)
If you're going to save this session into a disk file, start now.
Next, the RCP/M will display its sign-on and welcome messages, usually
including a few house rules, and then it will ask for your name. Unlike
some other bulletin boards, almost all RCP/Ms require your real name, and
unceremoniously erase users who sign in with fakes. Once you've given your
name, the RCP/M will check to see if it knows you. If it doesn't, it will
take you to a registration routine for new users.
Though many RCP/Ms allow new users access on the first call, many
others now require a verified registration. You may have to send a letter
to the sysop (the SYStem OPerator) giving your name, address, and phone
number; the sysop will send your verification and password by return mail.
This system is a pain for you, the user, and even more so for the sysop,
who must process all these requests. Most sysops feel they've been forced
to use registration by people, kids and adults both, who try to crash and
otherwise abuse their systems. (I ran a small RCP/M for a while and found
that people did indeed try to crash the system. Every day.)
If the RCP/M recognizes your name (because you've called before), it
asks for your password and then shows you the latest bulletins, including
system news and other things of interest. Most of the time, you can cancel
the bulletins by typing ^K.
THE MESSAGE SYSTEM
Once the bulletins are finished, you'll find yourself in the message
system, the real "bulletin board" of the RCP/M. As you enter (see Listing
1), the system will tell you when you last called, what the high message
number was then, what the present high message is, and whether you have any
messages waiting. It will then give you its command prompt; you can get a
menu of commands by typing a question mark (?).
An RCP/M may use one of several different message systems: Metal,
Oxgate, XBBS, RBBS, CBBS, or some other. On most systems, in most cases,
the major commands are the same as those in the Oxgate RCP/M menu (see
Listing 2). The commands you'll use most often are S and R, for scanning
and reading messages; E, for entering messages of your own; and G and C (or
J), for leaving the message system.
SCANNING AND READING MESSAGES
When I sign on to an RCP/M, I always scan the messages left since my
last visit, and I suggest you do also. For this visit to Oxgate, Listing 1
shows that my previous high message was 970, so I can scan all the messages
left since then by typing "S;970" at the command prompt. When you connect
with any system for the first time, all the messages will be new, of
course, so you can type "S;1" to scan everything.
The summary command will show you the date, sender, receiver, and
subject of all the public messages left, starting with whatever number you
specified. As the summary scrolls by, jot down the numbers of any that
look interesting so you can go back and read them. When the summary is
done, type "R" (for "read") at the command prompt. When the system asks
for a message number, type in the number of the first message you want to
read. When you've read that message, most systems will prompt you for the
next message number. When you're done, hit a carriage return to get back
to the command prompt.
ENTERING A MESSAGE
To enter a message of your own, type "E" at the command prompt. The
system will ask for the name of the person you're sending a message to
("ALL" for the general public, "SYSOP" for the system operator). Make sure
you spell the name right or else the person won't be alerted to the
message.
Next the system will ask for the subject of your message. You have
only about 20 characters to describe it, but try to be informative. Many
people may be interested in your subject and want to enter the discussion
(or just follow along), and I've gotten a lot of valuable information from
reading other people's exchanges. It's not considered impolite to read
other people's public messages, and it is perfectly acceptable to break in
with a comment or question of your own.
Then the system will give you a chance to make the message private or
public and to attach a password or not. Private messages can only be read
by the addressee, you, and the sysop (who can read everything); public
(normal) messages can be read by everyone, whether they're addressed to ALL
or to a particular person. A message with a password can only be killed
(erased) by the sender, receiver, or sysop, while a message without a
password can be killed by anyone. Some systems now automatically restrict
the killing of a message to the sender, receiver, and sysop.
Finally, you get to the actual message entry section. Most systems
limit the number of characters per line and the number of lines per
message; know these limits before you launch into a detailed message. You
enter your message one line at a time; if you make a mistake, you can
backspace and retype it, as long as you're still on the same line. Once
you start a new line, though, you can't go back--you'll have to finish your
message and then use the edit function to correct your mistake.
Hit two carriage returns in a row to end a message, and then you'll be
asked if you want to list (review), edit, continue, abort, or save it.
You'll find the editing functions pretty primitive on most systems. You'll
have to give the number of the line you want to edit, and then, in many
cases, your only option will be to retype the entire line. If you want to
add some more lines to the end of your message, you can use the continue
command. Once you're done with your message, use the list command to check
it over and then the save command (what else?) to save it.
Some RCP/Ms have very few messages, but the active ones have messages
of all kinds--pleas for help, discussions (technical and otherwise), user
tips, announcements and for-sale notices, bug reports, and general chit-
chat. These systems also have an informal etiquette. If you have any
information, even a little, that might help someone else, leave a message--
it's part of your contribution to the system. If you ask for help (which
is how most people get started), be specific about what your problem is,
when it occurs, and what equipment you're using. Make your messages
public, unless you have a good reason not to, so that other people can
learn, too. And remember, even when you're alone, talking to some RCP/M
3000 miles away in the middle of the night, you're in a public place; be on
your good behavior.
LEAVING THE MESSAGE SYSTEM
Every message system has other commands available (see Listing 2) but
I'll leave you to explore these on your own, except for the commands to
exit the message system. Typing "G" (for good-bye) at the command prompt
will log you off the RCP/M completely. Most RCP/Ms can recover if your
connection is suddenly broken by accident or a noisy phone line, but the
log off procedure resets the system more quickly and avoids any chance that
the RCP/M might get confused.
Typing "C" (for "CP/M") or sometimes "J" (for "Jump to CP/M") will
move you into CP/M, where all file transfers take place. The RCP/M will
close out your session on the message system and give you information on
what commands are available while in the CP/M section (see Listing 3).
Some systems also show you a map listing what kinds of programs are in the
different disk and user areas. The next thing you see will be the CP/M A>
prompt.
CP/M
Once you see the RCP/M's A> prompt (or it may be A0>), you should feel
right at home. Most commands now operate just as they do on your own
computer except that a few have been disabled (ERA, REN, and SAVE) and a
few have new capabilities (like DIR and TYPE).
You're now in the drive and user area (drive A, user area 0) where
most of the programs used to run the RCP/M are kept. If you type "DIR" at
the A> prompt, you'll probably see a number of COM files, including
DIR.COM, TYPE.COM, XMODEM.COM, and the main message system program, which
will be called RBBS.COM, OXGATE.COM, METAL.COM, etc., depending on which
system you've called.
If you're brand new to RCP/Ms, look for a program called HELP.COM,
which will give you information on how to use the system; just type HELP at
the A> prompt. If you don't find HELP.COM, look for a text file called
NEWUSER.TXT, HOWTOUSE.DOC, or something similar. If you find it, view it
on the screen by entering "TYPE NEWUSER.TXT" at the A> prompt. In either
case, make sure that you capture all this information into a disk file so
you can look at it later.
FINDING OUT WHAT'S WHERE
If the RCP/M didn't show you a disk map as you entered CP/M, look for
a program called SYSMAP.COM or MAP.COM. This program will list the
different types of software available (utilities, games, business) and show
where each is located so that you can go straight to the files you're
interested in.
If you want to see every file on the system, type "DIR *.* $U0AD" at
the CP/M prompt; this command will show you the directory of files in every
user area on every disk, one by one. Some RCP/Ms use the shorter command
"DIR *.* $AD" but also accept the longer form. WARNING--if you're running
at 300 baud and you're on an RCP/M with massive storage, it may take 20
minutes or more to complete this command, though you can always abort it
with a ^C. Make sure you save the results to disk.
GETTING AROUND
An RCP/M may have up to 15 disks (A-O), though most have only 2-4, and
each disk may be divided into as many as 16 user areas (0-15). You move
from one disk to another just as you do on your own system. For example,
typing "B:" at the A> prompt moves you over to disk B: and the prompt
becomes B>.
How you move to a new user area on the same disk varies from system to
system. On some, typing "USER 1" at the A> prompt moves you to user area 1
of disk A.
A>USER 1
A1>
Notice that the prompt becomes A1>. On other systems, you just type the
new user number followed by a colon:
A>1:
A1>
Most systems let you change disks and user areas at the same time, so
you can move from A1: to B3:, for example, with one command. On some
systems, you enter the new drive and user number followed by a colon:
A1>B0:
B0>
On other systems, you enter the new drive, a colon, a space, and then the
new user number:
A1>B: 0
B0>
You'll have to experiment to find out which method applies on the system
you've called.
WHAT TO DO WHEN YOU GET THERE
Once you've moved into a drive/user area that looks interesting, type
"DIR" at the CP/M prompt to get an alphabetized directory of files in that
area (see Listing 4). It's not always easy to figure out what you've found
even after you get the directory, so here are a few hints.
Files with the file type OBJ, like FILT6.OBJ, are ready-to-run
programs. All you do, after downloading them, is change the file type from
OBJ to COM (FILT6.OBJ becomes FILT6.COM). Sysops use the OBJ file type to
keep people from running these programs while connected and crashing the
RCP/M.
Files with the type DOC or INF, like FILT6.DOC, are text files that
document (give information about) a program. Using the TYPE command, you
can scan FILT6.DOC, for example, to find out what the program FILT6.OBJ
does. If you decide you want FILT6, download both the OBJ and the DOC
files.
Files with the type ASM, like MAGE31.ASM, are assembly language source
files, usually ones that can be turned into runnable programs by the CP/M
assembler ASM.COM that came with your CP/M system. ASM files are text
files, so you can view them with the TYPE command. They usually have
comments at the beginning to explain what the program does.
Squeezed files are files that have been compacted by a special process
so they take up less space. When a file is squeezed, the middle letter of
its file type is changed to Q: FILT6.DOC becomes FILT6.DQC, MAGE31.ASM
becomes MAGE31.AQM, and so forth. Ordinary CP/M commands and programs
can't handle squeezed files; they'll just fill your screen with junk. The
RCP/M's TYPE command will let you view squeezed files on the screen, but to
unsqueeze the file after you've downloaded it, you need a program called
USQ (for UnSQueeze) or NUSQ (for New UnSQueeze). Most RCP/Ms have a file
called SQ/USQ.DOC or SQUEEZE.DOC which explains how to deal with squeezed
files.
A file with the type LBR is a library file, a group of smaller files
collected into a master file that CP/M treats as a single file. For
example, the files FILT6.OBJ and FILT6.DQC might be grouped into the file
FILT6.LBR. Once you've downloaded an LBR file, any one of several
programs--DE-LBR, LU300, NULU11--will let you extract the member files so
you can use them. But how do you find out what's in the LBR file before
you download it?
RCP/Ms use one of two systems for dealing with LBR files. Some have a
program called LDIR, which will give you a directory of a particular
library. If you want to know what's contained in FRONT41.LBR (see Listing
4), you type
B0>LDIR FRONT41
Notice that you don't use the LBR extension.
These systems usually have an accompanying program, LTYPE, which lets
you view a text file member of a library on the screen. If you want to
look at README.DOC, which is inside FRONT41.LBR, you type
B0>LTYPE FRONT41 README.DOC
That is, you specify the name of the library (with no LBR extension)
followed by the name of the file within the library. (On some systems, the
regular TYPE command will also handle LBR files just as LTYPE does.) If
you forget what to do, type "LDIR" or "LTYPE" at the CP/M prompt for
instructions.
Other RCP/M systems use a program called LUX. On these systems, type
LUX followed by the name of the LBR file (such as LUX FRONT41), and LUX
will actually put you INSIDE the LBR file. You can then use DIR to get a
directory of the library, TYPE to view library members, SEND to download a
member from the library, HELP to get instructions, and control-C to exit
LUX.
UP AND DOWN WITH XMODEM
Once you've decided what files you want, you'll use the program XMODEM
to download them. If you type "XMODEM" at the CP/M prompt, you'll get a
brief description of how to use the program. To tell XMODEM to SEND the
file FRONT41.LBR to you (to download the file, in other words), you type
B0>XMODEM S FRONT41.LBR
XMODEM will sign on, tell you the size of FRONT41.LBR and the time it will
take to download at your speed, and signal that it's ready to send. At
this point, you must set your modem program to receive the file. Do this
quickly, as XMODEM will abort if you don't get going in about 30 seconds.
During the download, XMODEM will resend (up to 10 times) any section of the
file that isn't received cleanly.
If you just want to download one file from inside an LBR file (like
README.DOC from FRONT41.LBR), type
B0>XMODEM L FRONT41 README.DOC
Note that you specify the name of the LBR file, without the LBR extension,
followed by the name of the file you want to download from the library.
Everything else will proceed as with the XMODEM S command.
If you have a file that the RCP/M doesn't have, you also use XMODEM to
upload the file. To tell XMODEM to RECEIVE the file SUPERZAP.OBJ from you,
type
B0>XMODEM R SUPERZAP.OBJ
XMODEM will sign on, tell you where it's going to put the file, and signal
that it's ready to receive. Set your system to send the file, and
everything else will go as with downloading.
IMPORTANT FILES TO DOWNLOAD
RCP/Ms have many squeezed files and LBR files, so you must be able to
deal with these once you've downloaded them. I suggest you immediately
download USQ (or NUSQ, which is smaller and faster) and DE-LBR, along with
their associated DOC files. USQ will let you unsqueeze any squeezed file,
and DE-LBR will extract the member files from an LBR file. Many RCP/Ms
keep these and a few other basic programs in a special disk/user area
labelled STARTER.KIT or U-NEED.
RCP/M ETIQUETTE
RCP/Ms are busy 24 hours a day, so most have a strict limit (usually
one hour a day) on the amount of time you can spend on the system. Please
follow it--other people want to use the system, too. Almost all RCP/Ms
automatically keep track of when you called, how long you stayed on, and
what you downloaded or uploaded.
Do your part to help the RCP/Ms you call keep up their public domain
software collection: upload some files to balance out the ones you
download. You don't have to write the programs yourself; just pass on good
public domain programs you've found on other systems. Always check before
you upload to make sure the system doesn't already have the program you
want to send, and don't upload any commercial programs.
LEAVING CP/M
Once you've finished you're uploading and downloading, you can re-
enter the message system by typing RBBS (or OXGATE or METAL, depending on
what message system is in use). Or you can log off the RCP/M system
completely by typing BYE at the CP/M prompt; the system will say good-bye
and then reset itself for the next caller (who will probably be there about
10 seconds after you hang up). Please take the few seconds required to
make this orderly exit; it makes everything run more smoothly. Sometimes
when you type BYE, you'll be given the option of leaving a note for the
sysop before exiting. (Say thanks once in a while; these people work hard
in a good cause.)
Next issue, I'll cover the basic public domain utilities that everyone
should have.
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Ted Silveira is a freelance writer and contributing editor to several
computer-oriented publications. He appreciates suggestions or feedback
and can be reached through the KAY*FOG RBBS (415)285-2687 and CompuServe
(72135,1447) or by mail to 2756 Mattison Lane, Santa Cruz, CA 95065.
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