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Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 271
SEE ALSO: dA and dM test conditions, std.mk and 101.mk key mapping
script files.
29.6 Display Operation
When ZCOMM starts up, or regains control after a DOS Gateway, the
video mode and number of columns and rows are interrogated with a BIOS
interrupt call. If the columns are less than 80, or if the BIOS video
mode is between 4 and 6, the video mode is changed to 3 (color,
80x25). If other BIOS video modes cause problems, give a DOS "mode
co80" or "mode mono" command before starting ZCOMM. Display boards
with more than 80 columns or more than 25 lines are supported by the #
and $ numeric parameters (q.v.). By default, warpdrive is selected
for best performance.
ZCOMM supports extended EGA displays with ANSI 132 column escape codes
and the V numeric parameter. Special text video modes can be accessed
with the videobios command.
If ZCOMM is started with a Topview or DESQview virtual screen, the
video memory pointers are adjusted.
For special applications, the display may be completely inhibited with
a "display inhibit" command. Updating of the display is reenabled by
a display NOinhibit command or a fatal error disgnostic.
In addition, ZCOMM can emulate hard copy terminals by displaying
identical overstruck characters in bold (high intensity) and by
underlining characters when the overstrike involves the ASCII
underline character. This is enabled with a "display overstrike"
command. (With the Color/Graphics board, underlining is represented
by reverse video.) (A character position on the screen is overstruck
if the character position being written already contains a character.)
If the applications used involve backspacing and overstriking for
character editing, overstrike will produce random bold characters and
may be shut off with a "display NOoverstrike" command. Alternatively,
the term function subcommand ALT-O will toggle overstrike.
Normally, a received linefeed causes vertical movement only. If
nlmode is set with a "display nlmode" command, a received linefeed
also performs a carriage return. Nlmode is useful for Unix(TM) and
similar systems. ZCOMM's Nlmode setting must agree with Unix's nlmode
setting for screen oriented programs such as Berkeley Editor to
function properly.
Normally ZCOMM autowraps if there are too many characters on a line.
This can be turned off with a "display noautowrap" command.
Normally a received bell character will jangle the speaker with a
beep. The command "display bell=visual" silently displays BEL as a
(C) 1994 Omen Tech Inc Chapter 29 Terminal Emulation
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 272
flashing musical note without spacing to the next character position.
Most display adapters allow DMA access to the video RAM without snow
(sometimes called Chromablizzard).
When operating with older color/graphics display controllers (the
original IBM CGA board and clones), updating the display will cause
snow (sometimes called Chromablizzard). to appear on the screen
unless warpdrive is disabled.
EXAMPLE: display nowarpdrive
29.7 Non Standard Displays
ZCOMM defaults to a 80 by 25 display, with the bottom line used for
status information. Some displays support more than 25 lines and/or
more than 80 characters per line. In other cases, ZCOMM might be run
in a small window in multitasking environments such as TopView,
DESQview, or Windows.
The $ and # numeric parameters may be set to accomodate these
situations. A cls command should be given after changing the $ or #
numeric parameter. When ZCOMM starts up, the $ numeric parameter
(number of columns) is set according to the value returned by the
BIOS. ANSI 132 column escape codes are not recognized in windowed
operation. Chapter 24 describes these parameters.
(C) 1994 Omen Tech Inc Chapter 29 Log Entry Codes
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 273
30. LOGGING ENTRIES
ZCOMM can be set to keep various logs with the callers, calllog,
rcmdlog, rxlog, and txlog string parameters. Entries in the log files
include a code in the first column to indicate the conditions of the
operation associated with the entry. They are formatted as follows:
* An open file was implicitly closed when another file was opened or
as a result of a port or call command, or dialing a number.
> File skipped by receiver request. Log entry made iff the v numeric
parameter is greater than 0.
C Successful completion of a Compuserve B protocol file transfer.
C Call terminated by loss of carrier detect, bye or off command, or
dialing another phone number. Connect time is displayed in tenths
of minutes.
c An open file was closed with a close or ALT-C command.
E Operation terminated by error. Partially transmitted file skipped
by request.
F A transmit file was closed as a result of an end of file
encountered as it was transmitted by the term function.
g A transmit file was closed as a result of an end of file
encountered by the grab command, file received with the fget
command.
K Successful Kermit file transfer.
L Log entry of a host state login, connect time in tenths of minutes.
m Message received with the message or private command.
n The file name shown is illegal for the local operationg system, and
has been changed to "rename.###". The numeric value of ### is
shown in the count field.
R Successful file received with XMODEM family protocol.
Q Questionable filtransfer sent with XMODEM family protocol. On
receive: an EOT character was received but could not be verified;
the file may be truncated. On Send: All data blocks were
acknowledgd, but the EOT was not.
S Successful file sent with XMODEM or XMODEM BATCH protocol.
(C) 1994 Omen Tech Inc Chapter 30 Log Entry Codes
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 274
t File received with TWX convention (terminated by EOT, ETX, or ^Z).
U An incomplete received file was Unlinked (removed).
X Call terminated by off or x command or by software termination
signal.
x A file was closed implicitly when ZCOMM exited to the operating
system.
Z Successful file received with ZMODEM protocol.
z Successful file sent with ZMODEM protocol.
(C) 1994 Omen Tech Inc Chapter 30 Log Entry Codes
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 275
At the completion of a call, an entry in the call log is made
providing the calllog string variable is set to a suitable pathname.
A typical entry with 6.3 minutes connect time with a system called
cis02 is shown. The phone number is that given to Zcomm for
autodialing, contained in the telno string parameter.
C 2143:22 01-25-84 1200 c:226-0627 63 cis02
30.1 Performance Log
The plog string parameter enables file transfer performance logging.
The default empty value disables this function. Performance log
keeping does not affect the nolog command.
A sample entry is shown below. The fields are: effective speed[1],
log code, "L" for loss of carrier detect (otherwise blank), file name,
length, average transfer rate (characters per second), transfer time
in seconds (file open to file close), number of seconds required to
start the transfer, number of errors (retransmissions), flow control
transistions, block length/subpacket length (at end of file), measured
round trip delay time in hundredths of seconds, the command (or
facsimilie thereof), the other program's serial number (-1 if not
available), the directory entry or caller's name, and the hardware
handshake option.
2400 Z FOO.ARC 153760 186 826 1 20 260 256 234 sz 1171 guess who off
The above example shows 1 second to start the transfer, 20
retransmissions, and 260 times that YAM had to wait for flow control
release. This unusual set of figures is the result of a "networked"
transfer through the "cu" program on a Unix system to a PC, not a
normal connection or PC-Pursuit access.
The count of flow control transitions gives an indication of flow
control restraint applied by the modem, network, or receiver. Since
it counts the times YAM has entered a wait because of flow control
restraint and not the total amount of time spent in that state, it is
not an accurate quantitative measure.
The file transfer time and throughput calculation excludes the time
required to start the transfer, since that time is often not under the
protocol's control.
__________
1. The transmission speed unless set by the estimate command.
(C) 1994 Omen Tech Inc Chapter 30 Error (and other) Messages
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 276
31. ERROR (and other) MESSAGES
In the following messages, a %s refers to a filename or some other
name or string. %d or %ld refers to a decimal number. %x refers to
hexadecimal number, usually a character received from the modem.
Error messages referring to the XMODEM protocol and/or XMODEM/CRC
protocol also apply to the the YMODEM Batch protocol, which is an
extension of the XMODEM protocol. Most of the XMODEM error messages
are preceded by the sector and error number.
; not allowed with while The while command does not allow any
semicolons to exist on the rest of the line.
Aborting with error from remote: The remote Kermit program has aborted
the file transfer with the following message.
Access Password When ZCOMM is in host operation, callers must enter an
access password to gain access to the system, unless the string
parameter Password is empty.
Awaiting initial NAK When sending a file with the XMODEM protocol,
ZCOMM is waiting for the receiver to start the transfer with an
initial NAK character.
Awaiting pathname NAK When sending a file in the the YMODEM Batch
protocol, ZCOMM is waiting for the receiver to request transmission of
the file name, and length.
Bad Checksum An error was detected on the last block received with the
XMODEM or the YMODEM Batch protocol. ZCOMM will request
retransmission of the block.
Bad CIS ESC request %x ZCOMM has detected an undefined Compuserve
Protocol escape request. Usually due to a line hit or an aborted
transfer.
Bad CIS request %x ZCOMM has detected an undefined Compuserve Protocol
request. Usually due to a line hit or an aborted transfer.
Bad Command Please refer to Chapter 19 for legal commands.
Bad Condition Please refer to Chapter 27 for legal conditions which
may be tested by the if or while commands.
Bad CRC An error was detected on the last block received with the
XMODEM or the YMODEM Batch protocol. ZCOMM will request
retransmission of the block.
Bad CRC Length=n An error was detected on the last subpacket received
with ZMODEM. ZCOMM will request retransmission of the block. If the
(C) 1994 Omen Tech Inc Chapter 31 Error (and other) Messages
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 277
reported length is shorter than the nominal subpacket length the
problem may be incorrectly configured flow control at the sending end.
Bad Directory The directory given in a cd command does not exist or is
unreadable.
Bad Disk A command of the form D: attempted to change the default disk
to one that is not in the string parameter disks.
Bad Term Option Please refer to Chapter 22 for a list of legal Term
Options.
Bad Option Please refer to Chapter 20 for legal Options to the k, r
and s commands.
Bad Parameter The p command was given with an unknown parameter
letter. The parameters that can be set may be displayed with the p
command given without any parameter.
Bad parity Setting The 7{eoms} term option must be be one of e o m s
(even, odd, marking, spacing).
Bad SNP A valid and legal serial number-password must be entered with
the putsnp program.
Call Terminated An attempt at connecting to a remote system has been
abandoned.
Can't allocate buffer ZCOMM was unable to allocate memory for the
circular buffer, forcing an immediate exit.
Can't find Directory entry for %s A call or gosub command for name
failed because name was not found in the directory.
Can't open %s errno = %d The named file cannot be opened for reading
or writing (depending on the application). The common reasons are
listed below:
1 No such file or directory.
4 Bad file number.
5 Not enough core.
6 Permission denied.
7 File exists.
8 Cross-device link.
(C) 1994 Omen Tech Inc Chapter 31 Error (and other) Messages
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 278
10 Too many open files. (If this error appears when the specified
file is accessible, increase the number of available files with a
"FILES=20" statement in CONFIG.SYS.)
11 No space left on device.
14 Resource deadlock would occur.
Can't send pathname %s The receiver did not accept the named pathname
in a batch transfer.
No Carrier Detect The Carrier Detect signal from the modem (pin 8 of
the RS232 connector) is OFF. This is often caused by a bad modem
cable, or improper modem strapping options. Setting d term option
prevents ZCOMM from issuing this message.
Changing pathname An illegal pathname has been received. ZCOMM is
changing the pathname to one the local operating system will accept.
Checksum Bad rx=%x cx=%x The last block was received with a bad
checksum. The received checksum and the calculated checksum are
displayed. A retransmission request will be made.
Closing %s Reception of data for the named file has finished and ZCOMM
is closing out the file.
Command not allowed remotely Certain commands may only be given from
the local keyboard as they would sever communications with a remote
user in host operation.
Connected to Console Keyboard This message is sent to a caller when
the chat command is given in host operation.
*** DISK FULL *** If this message appears, your problems may have just
started; DOS has been known to trash the disk file system when the
disk is filled up. If the disk has been filled up as a result of
receiving data with the term function, use the t, b, w review
subcommands to store the unwritten data on disk. The browse command
may be used to free up disk space. The integrity of the disk file
system should be checked with chkdsk/f as soon as possible.
Enter message up to 64 lines, type blank line when finished The
message or private command allows the user (local, or remote when is
host operation) to enter a message which will be appended to the
Messages or Private file.
Error Checksum=%x Got %x An error was detected in a record received
from Compuserve. ZCOMM will request retransmission.
Error Recovery ZCOMM has detected a protocol error and is waiting for
the line to settle before proceeding.
(C) 1994 Omen Tech Inc Chapter 31 Error (and other) Messages
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 279
Exists. Replace/Append/Quit (r/a/q)?? The named file already exists
on the local system. You have three options: Replace the old file
with the new data, Append the new data to the end of the old file, or
Quit the transfer.
Exit chat with ^Z The remote should type Ctrl-Z to exit from chat back
to the ZCOMM prompt.
Falling back to XMODEM/CRC An attempted XMODEM-CRC file receive has
failed because the sender has not responded to CRC Send requests, so
Zcomm will now try checksum XMODEM.
FILES OPEN A transmit and/or receive file is open. Files should be
closed before executing any commands that would modify data on disk
and/or any directories.
Fetching pathname ZCOMM has requested the remote sender to transmit
the name and length of the next file in a the YMODEM Batch protocol
transfer.
found %d %s This informational message is generated when the term
function matches a pattern and the v parameter is non zero.
Garbled data subpacket An error was detected while attempting to
receive data with ZMODEM. This is caused by loss or corruption of
transmitted characters between the sending and receiving program.
Line noise and flow control mismatch are the common culprits.
Got %x for record ACK The Compuserve computer rejected the last record
sent.
Got %x for sector ACK In the XMODEM protocol, a transmitted sector
elicited a response other than the expected ACK, or a NAK. Perhaps
the receiving program has terminated and ZCOMM is trying to send the
record to the remote's operating system command prompt.
Got %x for ACK to EOT The XMODEM protocol sends an EOT to terminate
each file transfer. The proper response to the EOT is an ACK;
anything else is an error. ZCOMM resends the EOT up to ten times if
an ACK is not received.
Got %x sector header In the XMODEM protocol, A sector should start
with 01 or 02. (02 signifies a 1024 byte block.) An EOT followed by
extraneous characters appears as a sector header of 04 (EOT).
Got burst for sector ACK In the XMODEM protocol, sectors are
acknowledged with a single ACK (006) character. ZCOMM detects an
invalid ACK response by waiting two character times to make sure no
noise burst accompanied the ACK. It's far better to retransmit a
block which has been received correctly than it is to incorrectly
proceed to the next block, causing a synchronization error.
(C) 1994 Omen Tech Inc Chapter 31 Error (and other) Messages
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 280
Got record %x expecting %x A synchronization error has been detected
in the Compuserve protocol. The file should be deleted as it will
have been truncated.
Got ZCAN indicates the other program has encountered a fatal error and
has requested immediate termination of file transfer(s). To determine
the cause of this error, you must inspect the error messages displayed
by the other program.
Got ZRPOS indicates the receiving program has detected a transmission
error and has requested retransmission. In other words, ZMODEM is
doing its job of detecting and correcting missing and garbled data.
Please refer to Chapter 14 for more information.
Goto not in script context The goto command is valid only in a script.
Hit F1 to End When receiving data with the fget command, hit F1 to end
data collection. Any regular character is passed to the remote.
Hit any Key to stop When sending a file with the fput command, ZCOMM
samples the keyboard every so often to allow the operator to abort the
transfer. The keyboard is not scanned continuously because the
resulting overhead would impair the throughput available with the fput
command.
Incorrect The password entered is not the correct password.
Insufficient DOS FILES=# Add a FILES=20 line to the active CONFIG.SYS
file and reboot DOS to get a sufficient number of file handles to
support the level of script nesting required for your application.
Internal Stack Failure The number and/or size of DOS 3.2 internal
stacks should be increased, or a better operating system should be
substituted.
ioctl(m n) returned N: reason A Unix ioctl operation returned an
error. The first ioctl argument refers to the file descriptor; 0, 1
or 2 indicate a problem with the controlling terminal. Higher file
descriptor numbers (typically 6 or 7) refer to the dial-out serial
line.
The second ioctl argument is the command, shown in hex. This
corresponds to definitions in /usr/include/sys/ioctl.h and termio.h.
%s Is Illegal Device Device is not one of the legal devices in the
string parameter Disks.
Is Restricted Path When ZCOMM is Restricted, only the Home directory
and its subdirectories may be accessed.
Label %s not found A goto label command was given, but label could not
(C) 1994 Omen Tech Inc Chapter 31 Error (and other) Messages
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 281
be found in the same file as the goto command.
Loc 0 Corrupted An internal error (data stored into location 0 in the
data segment) has been detected. If not caused by a hardware problem,
please report to Omen.
Local Kermit Timed Out ZCOMM did not receive a Kermit packet from the
remote within the timeout specified by the Kermit t parameter.
Must set top with t command first When using the w subcommand from
review, the top of the buffer segment to be written must be set with
the t subcommand.
NAK on sector In the XMODEM protocol, the receiver detected a
transmission error and has requested retransmission.
No ACK on EOT In the XMODEM protocol, and EOT is sent and acknowledged
after the data blocks have been sent. This message indicates that the
EOT has not been acknowledged after 10 attempts.
No ACK on sector The XMODEM transmit protocol has retransmitted the
sector 10 times without receiving an acknowledgement from the
receiver. This is usually caused by a loss of connection, or by a
software or hardware problem that does not allow all characters to
pass without error. For example, if the modem cannot pass a character
with the 8th bit set, the sector number cannot be sent. Kermit should
be used under such conditions.
No Carrier Detect The Carrier Detect signal from the modem (pin 8 of
the RS232 connector) is OFF. This is often caused by a bad modem
cable, improper modem strapping options, bad port number selection, or
a defective or incorrectly configured serial interface. Setting d
term option prevents ZCOMM from issuing this message.
No such command The DOS Gateway handler was unable to load the proper
command and/or command.com.
Not allowed to overwrite %s When ZCOMM is restricted, existing files
may not be overwritten.
Nothing to read A read command was given and no file is open for
reading.
Null Pathname An attempt was made to reference a file with an empty
file name. This error sometimes results from a software bug in
Compuserve software attempting to download a file with a filename it
can't handle correctly, so it just leaves the filename empty.
Obey Recursion = %d The main command parser has been called
recursively with too many script levels and/or invocations of the obey
command.
(C) 1994 Omen Tech Inc Chapter 31 Error (and other) Messages
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 282
Other end no longer in Kermit
Other side timed out. The Kermit on the other computer has terminated
the file transfer.
Out of Memory ZCOMM has exhausted the memory available to it.
Output Flow Control Restraint RELEASED The network or modem did not
release flow control within the time limit set by the S numeric
parameter. This message is usually caused by a spurious XOFF
character generated by line noise. It may also be caused by missing
CTS (Clear To Send) signal on the data port.
OVERRUN: DATA May Be Lost Data has been received from the Remote
faster than ZCOMM could process it. Some of it has been rerouted to
the proverbial bit bucket.
Pause (grab) Sending of data has been stopped by execution of the grab
command.
Pause (handshake)
Pause (XOFF) Sending of data has been suspended by flow control.
Pattern Flags Reset This message is a reminder that any "pattern
found" flags are being reset. If this message appears after a phrase
has been "found", but before the phrase is expected, or before the
wait statement that should have "seen" the phrase, the script needs to
be modified.
Port %d (%X) defective The indicated communications port (8250
integrated circuit) failed a simple diagnostic test. Errors in the
option board switch or strap settings may prevent the port from being
accessible at the expected address.
PRINTER SPOOLER BUSY The print spooler has been enabled with the l
term option, and had not finished outputting from the circular buffer
to the printer when you exited the term function. To print the rest
of the data, return to the term function with F2. You may exit ZCOMM
at this time, but the rest of the data you wanted to print will be
lost.
Received dup Sector The last sector was apparently received twice. In
the XMODEM protocol, a retransmission is requested in case the sector
number was garbled by an otherwise undetected error. The duplicate
sector is accepted, discarded, and file transfer proceeds.
%s removed A file received in error is removed to allow another
attempt at uploading it correctly.
Restricted Command This command is not allowed when ZCOMM is
Restricted to protect the system from inadvertent and/or willful
tampering.
(C) 1994 Omen Tech Inc Chapter 31 Error (and other) Messages
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 283
Resynchronizing When ZCOMM is sending a file to another copy of ZCOMM
using CRC-16, recovery from sync errors is possible.
Scripts nested too deep Too many levels of call, gosub, and source
commands are active.
Sector number garbled An error has been detected in the sector number
of the last received packet. A retransmission will be requested. If
this error persists for all 9 retries, the transmission medium or the
remote software may be messing with the 8th bit and/or characters with
certain bit patterns. Modems and networks often "eat" control
characters, especially XON and XOFF. Switching to ZMODEM or Kermit
may solve the problem.
Sender CANcelled The Remote has aborted file transfers by sending a
sequence of CAN characters.
Serial Input Error: Line Status Register HH indicates a hardware
problem, slow device driver, TSR program, or other software is
disabling interrupts too long for the program to accept incoming data,
and some characters are lost. A slow response to flow control also
triggers this message.
The value of the line status register is displayed in HEX. The
following error conditions are OR'ed into the Line Status Register.
01 The Interrupt level circular buffer has been overrun. This
indicates a flow control problem. The remote did not respond to
ZCOMM's XOFF or hardware flow control signal, and continued to
send characters after being told not to. This problem is
alleviated by matching flow control between the sending computer,
modems, and the receiving computer. Usually, the mismatch exists
between the sending computer and its modem.
02 An 02 value (or any even number) for the LSR indicates Data
Overrun. "Data Overrun" means the computer was not able to
respond to an incoming character from the UART (modem) in time to
make room for the next incoming character. Data Overruns are
caused by poorly designed software and/or ROM BIOS "firmware"
locking out interrupts for excessive periods. These lockouts
prevent the communications program from responding to the
incoming characters in time to prevent data loss.
Other chapters in this document give suggestions for working
around excessive interrupt latency by using the NS16550AN or
other buffered UART chips. Please refer to the "Brain Damaged
UARTS" subchapter.
Please try all the suggestions mentioned here before contacting
(C) 1994 Omen Tech Inc Chapter 31 Error (and other) Messages
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 284
Omen Technology about data overruns.
Common causes of excessively long interrupt lockouts ("critical
code regions") are mouse drivers, disk drivers (BIOS), window
managers (Windows 3 is terrible), disk cache programs including
Microsoft SMARTDRV, TSR programs, and EGA/VGA board auto-select.
Slowing the CPU to allow games and other time dependent programs
to be used can generate excessive interrupt latency.
Some BIOS routines are written without regard to their effect on
high speed communications. Better versions of the offending BIOS
ROMS may be made available if enough users complain about poor
performance. In some cases disabling "multiple block transfer"
in the BIOS improves communications.
Interrupt latency caused by EGA/VGA board auto-select can be
often corrected by disabling the board's Auto-Select.
Device drivers and TSRs loaded in high memory sometimes cause
interrupt latency problems that can be corrected by moving them
into low memory.
Poorly written disk caches and disk drivers cause interrupt
latency that affects protocols. Some disk cache programs can be
set to cache disk reads only, avoiding the massive delayed writes
that interfere with file downloads. With Microsoft SMARTDRV.EXE,
try using the /E option.
Mouse drivers have been reported to cause loss of serial data.
If mouse movements interfere with file transfers, do not move the
mouse when transferrng files.
To correct Data Overruns, you must correct the offending
condition(s) to allow the communications program to operate
properly.
The handshake slow command can be used to stop reception during
disk transfers. However, handshake slow is not always an
effective alternative to correcting the real problem. When using
the handshake slow command, experiment with locking the modem to
different speeds. Sometimes a higher speed actually works
better.
The zmodem k numeric parameter can be set to flush the SMARTDRV
cache under controlled conditions. This may be used to reduce
errors caused by SMARTDRV. When used with SMARTDEV, set the
zmodem k numeric parameter to the number of kilobytes the should
be received before flushing SMARTDRV. This number should be low
enough to flush SMARTDRV before SMARTDRV periodically flushes
itself.
(C) 1994 Omen Tech Inc Chapter 31 Error (and other) Messages
Version 18.18 TurboDial 2.41 Universal Line Printer Edition
ZCOMM User Manual 285
Downloading files temporarily to a RAMDISK may help. Files on
the RAMDISK must be copied to a real disk before they are safely
stored.
!=2 With DOS flavors of ZCOMM one can select a 16384 buffer
size, you may be able to avoid problems receiving by using a
large i/o buffer and forcing ZMODEM to stop when this buffer
fills:
pI16384 z pl16384
or
pI16384 z pk1
If the I numeric parameter is non zero, it controls how often
SMARTDRV is flushed if the zmodem k parameter is non zero. A
CASE STUDY: NEC UltraLite VERSA The NEC UltraLite VERSA provides
a case study of how brain damaged hardware and software
interferes with high speed communications, and what can be done
about it. A NEC UltraLite VERSA with 8 MB of memory contains
about 70 million transistors and costs upwards of $5000.
Unfortunately this machine lacks the hundred transistors
necessary to buffer input on its built-in serial port. This port
is built in, so replacing it with a better UART ship is out of
the question. In normal operation interrupt latency caused by
the NEC's device drivers and DOS cause errors at 38400 bps and
above.
Setting the zmodem k parameter to 50 or 100 reduced overruns by
stopping transmission briefly before disk writes.
The best operation was obtained by hitting the F5 key while DOS 6
loads to bypass all device drivers and TSR programs. Operating
this way there were no data overruns (LSR 02 errors) at 38400
bps. Operation at 115200 bps was possible by setting a large I/O
buffer and using the zmodem k numeric parameter. I was able to
download AM.DAT (a 15762427 byte FCC database of North American
AM broadcast stations provided on the "Ham Call" CDROM) with 3471
cps throughput using ZMODEM compression. While nowhere near as
compressible as Columbia University's Kermit News compressible
benchmark file, this highly compressible file provides a stress
test for compressed transfers because of the resulting heavy disk
I/O.
08 Framing Error generally caused by line noise or an incorrect
transmission speed ("baud rate") or format (number of bits).
Also caused by some cheap internal modems. Most protocols
require 8 bits no parity (-8n) for proper operation. This is set
automatically by Omen Technology programs, but other programs may
not be so smart.
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10 Break Interrupt generally caused by line noise or an incorrect
transmission speed ("baud rate") or format (number of bits).
Also caused by some cheap internal modems.
18 Framing Error and Break Interrupt (see above) in combination.
This error may also be caused by defective 8250 UART chips. Some
internal modem cards have slow 8250 chips that do not operate
properly with computers faster than 4.77 mHz. Replacing the 8250
with a NS16550AN is recommended. Please refer to the "Brain
Damaged UARTS" subchapter for details.
Setab: %d %s The displayed string of length %d has been queued to be
sent to the remote as a result of a put, or putw command, or an
answerback request. Setab is also used in sending entstr in response
to typing ENTER.
*** STACK OVERFLOW *** Indicates ZCOMM has run out of memory for the
program stack. Do not pass go, do not collect $200. Reboot the
system with Ctrl-Alt-Del. If you are using a large number of string
variables, or if you have a large DOS enviornment, decreasing the size
of ZCOMM's circular buffer with a DOS "set CBSIZE=" command may help.
If this appears to be a ZCOMM software problem, please report it to
Omen Technology Inc.
String too long The string would have been longer than the storage
space allocated for it.
Sync Error: got %d In the XMODEM protocol, a sector was received whose
sector number does not match the expected sector number modulo 256, or
the last sector number received modulo 256. This usually happens when
a transmission error causes the sender to receive a false ACK.
Unless the o (OverThruster) or g option was used,[1] ZCOMM will
request retransmission in case the invalid sector number was a result
of a line hit. If the file is being sent with CRC-16 by another copy
of ZCOMM, resynchronization will be attempted after ten retries.
Term Function Recursion = %d The term function has been forced to call
itself recursively by f or t commands. Use open or create commands
instead.
__________
1. These options prevent error recovery.
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Timeout The Compuserve computer has not sent any data for a long time.
When things get this slow, it is best to disconnect and ask Compurerve
to credit you for wasted connect charges.
Timeout on sector ACK In XMODEM protocol, ZCOMM times out waiting for
an acknowledgement to a transmitted sector.
Too Few arguments The command needs more operands than were given it.
Transaction ABORTED BY ERROR / successful The message indicates the
ending status of the last file transfer or command download. If a
file transfer ended in error, the last file may be truncated.
Transfer Aborted: %ld Characters Received The Compuserve protocol has
aborted file transfer due to an error.
Transmit Data. When data has been sent, close it by typing ^Z When a
remote caller has created a file with the t filename command, ZCOMM
indicated readiness to receive data with this message. When the file
has been transmitted to ZCOMM, a Ctrl-Z will close the file.
Unknown Machine Type ZCOMM looks at the ROM BIOS location F000:FFFE to
determine whether it is running on a PC, XT, PC-jr, or PC-AT. If the
byte fetched in not a standard IBM value, ZCOMM complains and assumes
the machine is equivalent to a PC or XT with respect to clock speed
and i/o overlap. SEE ALSO: o numeric parameter
Unterminated Quoted Token A string token was quoted with a leading "
(doublequote) character, but no matching " (doublequote) could be
found on the same line.
Waiting for call %d ZCOMM is in host operation and is awaiting call N.
If n is greater than 1, then n-1 calls have been received since ZCOMM
was invoked.
Warning: Old dport=%x ier=%x out2=%x mask=%x isr=%08lX When selecting
a port, ZCOMM has discovered that the port's interrupt enable bit was
already set. Some programs use modem interrupts for their operation
but then fail to reset the interrupt enables when they exit. When
another program overlays the old program's interrupt service routine,
an interrupt from the modem will transfer control to the overwritten
memory locations, with unpredicatable results. If the interrupt was
set up by a memory resident program or device driver, this message may
be ignored. This information might be useful in the event of
difficulties caused by such programs. This message may be suppressed
by defining the DOS environment variable HOTPORT.
EXAMPLE: C>set HOTPORT=1
SEE ALSO: port, portx commands
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Wrong number of arguments The set command accepts 0 arguments (display
current values) or two arguments, the parameter name and the new value
for it.
XON Timeout The Kermit protocol (with the x option set) has timed out
waiting for an XON character.
ZMODEM Garbage count exceeded The reciever has detected a CRC or other
error and signalled the sender, but the sender apparently has not
received and responded to the retransmission request in a timely
manner. Usually caused by transmission line noise corrupting the
retransmission request as well as the file data, or by an excessive
number of characters stored in the modems and networks.
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32. HINTS AND KINKS
32.1 Recursive Function Key Definitions
When defining function keys for use within the term function, do not
use the t or f commands. Instead use the create or open commands to
prevent excessive recursion (term function chasing its tail).
32.2 Noisy Data Lines
Users have reported line noise caused by some types of telephones
attached to the same line used by the modem. When reporting line
noise troubles to the phone company, remember you pay for the service
call if the trouble is traced to your equipment.
32.3 UUUUUUU from 212 modems
Sometimes a 212 modem will send UUUUUU ad nauseam because it has
received (or thinks it received) a command to enter remote digital
loopback. Disabling the modems' remote digital loopback feature (when
possible) prevents this form of "lock-up".
32.4 Funny Business with the Phones File
When trying out new ideas in the Phones file, make sure that ZCOMM is
actually reading the file you think it is by inspecting the value of
the phones string parameter with the "set" command. You might find
that you were editing one file and ZCOMM was reading a different one.
32.5 Losing Keyboard Characters
Generally, ZCOMM does not throw away keyboarded characters that are
typed before ZCOMM prompts for them. However, many commands,
especially wait, invoke the term function which sends any characters
in the keyboard queue to the remote before returning to ZCOMM's
command prompt. In general, any time you see the term function's real
time status line, keyboarded characters will be acted upon immediately
(usually by being sent to the the remote).
32.6 Browsing Through Messages
The vast amount of information on bulletin boards requires some heroic
measures on the part of a user desiring to keep current without
spending all his time wading through the mass of mostly unintersting
messages.
ZCOMM addresses this problem with its script facility which can
download messages from a number of bulletin boards on one or more
systems with human intervention.
The read command and "/" and "n" review subcommands can be used to
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skip from one article to the next by searching for the subject line of
each message. Since the subject line of each message always appears
at the top of the screen, you can keyboard the "n" key quite rapidly
without waiting for the display to completely fill. If you overshoot
a message or two, the "N" command can be used to back up. You'll be
pleasantly surprised at how rapidly you can review message subjects
this way.
32.7 Splitting Up Files
Sometimes it becomes necessary to split up a large file into smaller
files, or to extract small pieces from such a file. For example,
Daisy Wheel printers sometimes jam the paper halfway through printing
a file. Rather than reprint the entire file, use ZCOMM's open and
seek commands to locate the beginning of the desired segment, then
read it into the circular buffer with the read command. Then hit F2
for review, place the top line on the first line desired, and type
"t". If the desired segment fits within the circular buffer, use the
"b" subcommand followed by a "w" subcommand to write the segment to
disk.
If the segment is too large, use the "w" subcommand without a "b"
subcommand to write the entire buffer beginning at the location of the
"t" command. Then kill the buffer with the "k" subcommand, returning
to ZCOMM's command prompt. Another read command can be given to get
the next segment of the file into the buffer. At this point, you can
enter review as before to store another segment. Alternatively, you
can use the create command to open a receive capture file, then write
the buffer contents to it with a w command. Then use kill to clear
the buffer, and repeat this cycle until the end of the file is
reached.
32.8 Refresher Courses
After you've read the manual and used ZCOMM for a while, go back and
skim the manual again. You will grok new concepts that were so
obscure the first time you didn't know you missed them.
32.9 PC <--> Macintosh File Transfers
I do transfers between IBM PC type machines to a Fat Mac and Mac Plus
(one upgraded to the other) all the time. I discovered the
Macintosh's RS-422 port does not have enough signals coming out of it
to properly drive the IBM PC RS-232 serial port without an adapter.
So, get two female DB-25 connectors. On the PC side, tie pins 4-5
together, and tie 6-8-20 together. This insures that the PC sees CTS,
DSR and RLSD/DCD so your IBM comm program will see them.
I prefer using the comm port on the Mac because you can go up to 56
kilobits/sec on it (I use ProYAM on the PC and Microphone on the Mac,
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which offers 38400 bit per second transfer capability with no errors).
Between the two connectors, connect 7 to 7, 3 to 2, and 2 to 3. If you
prefer to use the printer cable, connect 7 to 7, 2 to 2, and 3 to 3.
Edited from a message by Stephen Satchell, Satchell Evaluations (used
with permission)
32.10 Acoustic Coupler for Portables
Having a portable computer with a direct-connect internal modem is
really great - until you try to use it at a pay phone in the airport.
The modular jack does not connect to public telephones.
I found one device that overcomes this problem (and it needs to be
advertized more). It is the acoustic adapter that 3M sells with their
WhisperWriter portable terminals. Model 1490 acoustic coupler
connects the 3M teleprinter to public phone lines through a telephone
handset. It is recommended for applications where direct connection
to phone lines is either not practical or not desirable. The device
consists of a pair of rubber cups, a modular jack, and a battery
powered audio amplifier set. You simply run a 3-foot modular line
from it to your PC, and put the pay telephone's handset in it. Price
is less than $80, it works with 300 and 1200 baud internal modems, and
should work at 2400.
In the Silcon Valley, the distributer is 3M Data Systems (408)866-
8811.
This information comes via Usenet from Joe Smith at SU-SCORE.
Another acoustic coupler is made by CP+ Inc (Computer Products Plus,
Inc.) at 800-274-4277, 714-847-1799. It connects to the modem with a
standard modular plug.
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33. HARDWARE/SOFTWARE COMPATIBILITY
33.1 Hardware Compatibility Notes
IBM PS/2 Model 50Z Early samples of this machine have a design error
on the motherboard that causes comms programs to lock up the
machine. Replacing the motherboard with a correctly functioning
unit from current production corrects the problem. The part number
of the replacement PS2/50 Z motherboard is 35F5928. (Information
provided by John M. Choma 73047,3566) In the U.S. IBM has
stonewalled on this issue, but in December 1988 agreed to replace
the defective motherboards under warranty.
Zenith Computers Older Zenith computers may need a ROM update to work
properly with interrupt driven programs such as ZCOMM.
NEC Multispeed The NEC Multispeed computer locks up unless STACKS is
set in CONFIG.SYS. In addition, one should disable floppy disk
power save mode, and set popup program memory allocation to 0. For
best results, use the latest NEC software patches to the NEC MSDOS,
and/or use an IBM PC-DOS instead of the DOS supplied by NEC.
EGA/VGA Multimode Boards Some multimode EGA and VGA boards include an
"auto select" feature designed to configure the board to various
display standards using software trickery. In the case of Paradise
VGA and others, this feature causes excessive interrupt latency and
loss of data at high speeds. Disabling the auto select on the
display board corrects this problem.
EGA Wonder The BIOS in the ATI EGA Wonder has been observed to
increase interrupt latency to the dismay of 9600 bps operation on an
8 mHz no wait state AT clone. There has also been a report
(unexplained) that an EGA board has induced line noise in one
instance.
Tecmar Graphics Master To use ZCOMM with this display board, give a
mode mono command before running ZCOMM.
Leading Edge MODEMS and I/O BOARDS Some Leading Edge modems and
interface boards use 8250 UART devices that do not respond correctly
when the software turns the transmitter interrupts on and off. High
performance communications programs such as ZCOMM require properly
functioning UART chips, such as the National Semiconductor 16450 or
16550A.
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33.2 Brain Damaged UARTS
Omen Technology has received reports of problems with buggy 8250 type
UART integrated circuits in Leading Edge modem boards, serial port
interfaces, and computers. The defective chip logic affects high
performance software. Replacing the buggy chip with a newer chip
(NS16550AFN) corrects the problem.
The UM82450 chip in the Zoom 2400HC also appears to cause problems.
Zoom Telephonics advises that this problem is limited to their old
model. The old model has an external volume control.
You can identify an old chip by inspecting the serial interface board
for 8250 or UM82450 type devices. A service technician or hardware
hacker can help if you are not familiar with reading chip numbers.
Dsz users can identify old chips with the following software command:
EXAMPLE: dsz port 1 speed 2400 p
The resulting value for the P numeric parameter should be 1. A value
of 0 indicates a non-buffered chip or a chip with a defective buffer.
ZCOMM and Professional-YAM users can look at the printout produced by
the s command; old UART chips register as TYP 0.
Some internal modems and PCMCIA cards use a firmware simulated UART
that is not detected as a buffered UART. Properly designed firmware
UARTs provide excellent buffering.
The National Semiconductor NS16550AFN is a pin compatible plug in
replacement for 8250 and 16450 serial chips. Omen Technology PCDOS
software enables the FIFO buffer in the NS16550AFN to prevents loss of
data from poorly written device drivers, TSR programs, etc.
We are also using the Goldstar GM82C550 chip with a 9025 date code.
This Goldstar chip is plug compatible with the National chips. No
problems have been discovered with this chip.
The NS16550AFN has better electrical characteristics than the older
UART chips. 386 and fast 286 machines should use the NS16550AFN for
best results. Omen Technology software has been written to allow time
for the older UART chips to operate. However, there is a limit to how
much the software can rearrange chip accesses without resorting to
performance robbing wait loops. Some other software is not as
forgiving of slow chips.
Fortunately the FIFO UART chip situation continues to improve. As of
this writing, the following plug compatible chips are known to work.
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+ Goldstar GM82C550,
+ National Semiconductor NS16550AN and NS16550AFN
+ Startech 16550
Current Western Digital WD16C550 chips do not function properly at low
speeds.
The Startech 16C552 contains two UARTS and a buffered parallel
interface.
If your UART chip is soldered in or otherwise not replaceable, you
will need a new plug-in board with a good UART chip. Byte Runner
Technologies 800-274-7897 offers a variety of boards and chips.
Another is the KW-524E-1 Serial/Parallel/Game card, $30.90 from TSD
Systems, 800-331-9130 (FAX 407-331-8130). A board populated with two
FIFO UARTS is $41.85.
The Hayes ESP board comes with two serial ports with NS16550AFN
devices. The ESP definitions for COM3 and COM4 agree with the
industry standard definitions used by Omen Technology. All option
switches on the ESP board should be OFF except those used to select
the port number (COMn).
The $99 "WinSport II" from Boffin LTD 612-894-0595 has two NS16550AFN
FIFO UARTS and also supports MobyBaud (18.432 MHz clock). This card
also supports higher IRQ numbers, freeing up the low IRQs for other
applications.
Software Electronics 503-640-1946 sells a $59 board with two FIFO
UARTS and a bidirectional enhanced parallel port.
The following information comes from a number of people:
"I have located a small dealer in New York who has the cards with or
without the 16550. I believe the price is around $50.00. The company
is RJK Consulting and the number is 718-968-9167. The gentleman to
speak to is a Mr. RJ Kulman. ... I got this information off the
"Interlink" BBS system." Fm: Nick Braak [TRICON] 75156,1254
Fry's - 415-770-FRYS. This is a Silicon Valley electronic department
store.
Jameco Electronics at 415-592-8097 800-538-5000 sells National
NS16550AFN chips mail order (credit card) in small quantities.
Unfortunately, we received a number of reports (none recently) that
their serial i/o card was supplied with the defective WD16C550
soldered in, even when ordered with specific instructions to include
16550AFN chips.
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TSD Systems advertise a 2 serial/parallel/game card with one or two
NS16550-AFN chips. 800-331-9130(voice) 407-331-8130(fax)
Microprocessors Unlimited, 24000 South Peoria, Beggs, OK. (918) 267-
4961. The price for the chip is $13.50 plus shipping costs.
Consolidated Computers 4 Shoppers Lane Suite 121 Turnersville, NJ
08012 (609)751-9595(voice) (609)751-3843(bbs) (609)751-3840(fax)
Arrow Electronics at 800-932-7769 (516-467-1000).
Willies Computer Software Company: 800/835-4832.
N.B.: Current Western Digital WD16C550 chips do not function properly
at low speeds. This has been confirmed with samples received directly
from Western Digital. WD is aware of this problem, but has not
informed us of a corrected chip.
33.3 Software Compatibility
Some programs and device drivers affecting the operation of PC-DOS may
interfere with ZCOMM, especially when ZCOMM is operating at high baud
rates. Historically, loss and corruption of data have been caused by
memory resident programs. Some of these programs increase interrupt
latency preventing ZCOMM from reading a character from the UART
holding register before the next character comes in on top of it. In
other cases, programs do not properly restore the state of the machine
when they exit from interrupts.
If such a problem is suspected, run ZCOMM without any memory resident
programs or special drivers to locate the source of the problem. Once
the offending program is identified, a call to the program's vendor
may obtain a corrected version.
The design of memory resident programs is a little known black art.
Subtle bugs, non reproducible interactions, and magic combinations are
commonplace results of attempts to impose various aspects of
multitasking on top of an operating system that was not properly
designed to permit such extensions. Omen Technology Inc may be able
to help identify these interactions if provided with the source code
of the offending programs.
Some of the known troublemakers are mentioned below.
Smartdrive This disk cache program (Windows 3.1 version) has been
observed to cause communications errors even when a FIFO UART is
used.
BREAK ON This DOS command causes ^C to be intercepted by DOS at
various, sometimes awkward, times. BREAK ON must be used with
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extreme caution as interrupting most programs with ^C compromises
the integrity of the file system. If a program is interrupted by ^C
or Ctrl-Break, the file system should be immediately checked with
CHKDSK. In some cases it may be necessary to reboot DOS with Ctrl-
Alt-Del if DOS runs out of file descriptors. A synonym for BREAK ON
might be NUKE FILESYSTEM ON.
Someday MicroSoft may discover what to do with ^C (DEC figured it
out about two decades ago). In the meantime, we recommend you not
use it. When ZCOMM starts up, it stores the status of the BREAK ON
flag, then clears it. On Exit, or when calling a DOS program, ZCOMM
restores the BREAK ON flag to its previous state.
Disk Cache Programs Microsoft SMARTDRVIVE Norton NCACHE Multisoft
PCQWIK Many disk cache programs tie up the computer long enough to
lose modem data. (It only takes a few thousandths of a second!)
Some disk cache programs are worse than others. Some are so bad not
even a FIFO UART can overcome them.
Some programs (SMARTDRV) can be set to cache disk reads only,
avoiding the delayed writes that disrupt file downloads.
Mouse Drivers Some mouse drivers have been reported to interfere with
file transfers.
DOS append command The DOS append command allows one or more
directories to be partially "grafted on" to a specified directory.
Some DOS system calls "see" files in the new directory, some do not.
This interferes with file transfer options such as -y, -r and -n.
If the DOS append command must be used, use the /x:on switch.
TOPDOS TOPDOS, ver 2.00i by Frontrunner Development Corp., has caused
ZCOMM and other programs to lock up. Disabling TOPDOS restores
normal operation.
DOS 3.2 DOS 3.2 introduces the concept of a fixed number of interrupt
stacks. The default value chosen is not always sufficient, and DOS
3.2 sometimes prints the infamous Internal Stack Failure message and
cheerfully halts the computer. Adding the line STACKS=20,128 to the
CONFIG.SYS file should correct the problem. Lacking any useful
documentation from Microsoft, you may wish to experiment with
different values.
Extended Memory RAMDISKS Extended Memory electronic disks (ramdisks)
require the 80286 chip to switch in and out of protected mode during
block transfers. A hardware reset pulse is used to switch back to
the "real mode" required for DOS. This causes loss of modem data at
high speeds.
It may be possible to reduce excessive interrupt latency by reducing
the length of protected mode block transfers to 128 or less. In one
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instance, replacing the ROM BIOS with a newer version increased the
maximum transmission speed without losing characters to 9600 bps.
This problem has not been observed with expanded memory
(Intel/Lotus/AST/etc.) ramdisks.
The new generation NS16550AN or 82510 serial interface circuits
should be used instead of 8250's for best results at high speed.
The NS16550AN allows operation at a communications speed of 115200
bps compared to 9600 bps (typical) for the 8250 and 16450.
Disk Drivers Disk drivers, especially hard disk drivers for 80286
machines, lock out interrupts for varying periods of time. The
actual interrupt latency depends on the speed of the computer and
the particular BIOS code used. In one case, upgrading to a newer
BIOS allowed operation at 38400 bps, compared to 4800 bps
previously. Such an improvement is well worth the small ($25
typical) cost of a new set of ROM BIOS chips.
DOS 3.x Each new version of PC-DOS adds new features and eats up more
of the 8088's meager resources. DOS 3.2 increases interrupt latency
enough to interfere with ZCOMM's operation at 19200 bps on an IBM
PC. If this is a problem, switching to DOS 2.1 will reduce the
interrupt latency. Replacing 8250 and 16450 serial interface chips
with the new NS16550AN chip allows ZCOMM to operate smoothly at high
speeds.
FANSI-Console Versions of this program before 1.07 did not maintain
the pointer to the active display board in the IBM documented memory
location. A DOS mode command may cause ZCOMM to reference the wrong
display adapter address. This caused incorrect sync signals and
possible damage to certain monitors. Current versions (2.X)
increase interrupt latency enough that the serial line drops
characters when the keyboard is touched.
Seaware Batch Versions of this program has been known to cause loss of
data.
Spotlight/Lotus Metro This TSR program has been reported to cause
ZCOMM to lock up.
Pathname Modifiers Programs such as FILEPATH and GLOBALS allow files
to be visible in more than one directory at a time. Such programs
may interfere with security when ZCOMM is restricted, since that
security is based on restricting access to directories. In general,
sensitive files should not be made global when ZCOMM is made
accessible to outside callers.
ZCOMM may not recognize file names generated by such programs unless
the program traps the DOS FINDFIRST calls as well as the file open
calls.
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We have received various reports of strange behavior which have been
traced to filesystem modifications caused by such programs,
including damaged file systems. We recommend such programs be
phased out as soon as possible, as they may not operate at all with
future versions of DOS or distributed file systems.
BRKBOX This program locks out interrupts up to 17 milliseconds while
waiting for the vertical retrace. For a communications program, 17
milliseconds is a very long time, and data will be lost at speeds
above 300 bps.
CGCLOCK Programs such as CGCLOCK.COM use clock interrupts to update a
time display on the screen. Some increase interrupt latency so much
that ZCOMM cannot respond in time to accept characters from the
remote, even at 1200 baud.
Concurrent PC-DOS ZCOMM runs under Version 4.1 of Digital Research
Concurrent PC-DOS (CPCDOS). The - numeric parameter must be set to
0. The CPCDOS "addmem" command should be used to allocate extra
memory if DOS Gateway are to be used.
ANSI.SYS ZCOMM uses direct keyboard input from the ROM BIOS because
the DOS keyboard input calls do not handle Ctrl-BREAK properly. As
a side effect, keyboard keys redefined by ANSI.SYS have no effect on
ZCOMM's operation. It is possible to program some of the keys to
call ZCOMM with arguments. The following file, reassigns ALT-C,
ALT-H, and ALT-V to execute the commands shown below. The $
character represents ESCAPE.
$[0;46;"cd \tmp";13;"ZCOMM call -200 cbbs-r";13p
$[0;35;"ZCOMM call host";13p
$[0;47;"cd \tmp";13;"ZCOMM call cissig";13p
ZCOMM uses the ROM BIOS CRT functions and direct output to the
display, bypassing any processing provided by ANSI.SYS. Perhaps
someday Microsoft will enhance ANSI.SYS to make it useful for
programs like ZCOMM ...
PRINT.COM Once the DOS PRINT program is memory resident, file
downloads at high speeds (38kb on a PC) suffer from interference,
even if a file is not currently being printed.
With certain printers, the DOS PRINT command will preempt the
running program for several seconds at a time. These "swapouts" can
be confusing when you are accessing an interactive application.
They may interfere with file transfers, especially if the remote
program uses "tight" timing. If this happens, PRINT should be
suspended during file transfers. Operation of the PRINT command
does not appear to cause loss of data downloaded from timesharing
services at 1200 bps, as long as the interruptions last less than
ten seconds. Perhaps IBM or Microsoft will someday fix this bug in
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the DOS PRINT command. PRINT should not be invoked from ZCOMM for
the first time as DOS memory allocation will become fragmented.
If PRINT or some other spooler is outputting to a serial port using
the BIOS INT 14h serial port driver, ZCOMM's "!~subprogram" command
will redirect the printer output to the remote and thus should be
avoided.
SWITCHAR = - ZCOMM will work properly when the DOS switch character
is set to "-", allowing Unix style pathnames. The - numeric
parameter must be set non zero to allow ZCOMM DOS Gateway to use /
to delimit directories.
It may be necessary to remove this line from CONFIG.SYS and reboot
DOS before using the IBM dump and restore commands.
N.B.: DOS 3.0 does not support SWITCHAR in the config.sys file. A
short program, DASH, will set switchar to -. It prevents many
oaths. Microsoft has removed all SWITCHAR support in DOS 5.0. So
much for POSIX compliance.
For demanding applications requiring sophistication, power and support
not provided by any user supported communications program, Omen
Technology provides Professional-YAM Integrated Communications Tools.
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ZCOMM User Manual 300
34. BACKGROUND OPERATION
ZCOMM and the help processor YHP run under TopView, DESQview,
Carousel, and Windows, PC-DOS based multiprogramming systems that
support virtual video memory access.[1]
These operating environments allow multiple programs to run
concurrently on the same computer. Vertical applications can use the
high level menus to simplify the customer interface.
The default "performance settings" allow nearly full speed file
download and scripted data capture from dial-up services when other
processes are not accessing the floppy disks. Launching programs and
manipulating windows may cause communications errors.
NOTE: Do not run multiple windows with programs accessing the same
COMM port. If you wish to run more than one program accessing a
specific serial port, close (terminate) the window running each
program before opening a window for another program addressing that
port.[2] It is not sufficient to merely suspend a comms program, it
must be terminated before another program can access that port without
interference.
Tell DESQview to use the SPECIFIC port number you are using, and not
"Y" to the question: "Uses serial Ports (Y, N, 1, 2)" DOS's file
system semantics can cause unexpected results when one program is
writing to a file while another program is reading the file. Unlike
Unix, data written by a program does not become visible until the file
is closed.
Program Information parameters: 256k is suggested for ZCOMM. If
memory is scarce, ZCOMM can run in about 196k with no DOS Gateway
allowed and the circular buffer made smaller with a "set CBSIZE=4000"
command given to DOS before starting HK. ZCOMM* and YHP do not write
directly to screen, do not access system keyboard buffer, run in the
background, use their own colors (optional), accept keyboard
typeahead, and the window may close on exit to DOS. ZCOMM cannot be
swapped because modem interrupts call ZCOMM directly.
__________
1. BIOS interrupt 10h, ah=0FF and ah=0FE
2. Some programs, such as ProComm, lock two ports at the same time
even when using only one port. Such programs will interfere with
comms programs running in other windows.
(C) 1994 Omen Tech Inc Chapter 34 Background Operation