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RE: [N8VEM-S100:139] File Transfer

Rich, if you have time you may want to try the 'PCGET & PCPUT" programs I
described here

for  quickly moving of files to/from a PC/S-100 system.  They are stripped
down versions of Ward Christenson's MODEM program. Just asks for file name
(erases old file if present) and goes to it.  I have been using it for years
now. With a USB port on the S-100 bus
file transfer is essentially instantaneous. But even old serial ports are

You can use one of the many TELNET interfaces you like on the PC end -- I
use the Celestial Software one "Absolute Telnet"  one.   Using one of those
USB to serial cable connectors/converters the whole thing is simple &
reliable. I leave the connection between the two systems in place and just
use when required.



-----Original Message-----
From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On
Behalf Of Rich Leary
Sent: Saturday, April 02, 2011 10:27 AM
To: N8VEM-S100
Subject: [N8VEM-S100:139] File Transfer

Eventual addition of a CF or SD card interface to my S-100 system should
make file transfers to or from PC and S-100 (or other systems I have
including Kaypro 10, C-128, N8VEM V1, SBC-2, SBC-3, and some others I am
forgetting) easy. In the meantime I have been experimenting with alternative
connection methods. I thought you might find some of those efforts and
results interesting.

a. I tried using the NetBurner SBL2e X Serial to Ethernet device on my
"modem" port on the S-100 Interfacer 4. On the PC end I used Hyper Terminal
Personal Edition as I was using my Windows 7 laptop. What I quickly
discovered is that the NetBurner is a great device (more on that later) but
that using TCP/IP does not work for XMODEM transfers.
XMODEM demands 100% transparency and a TELNET interface is not 100%
transparent. Since I liked the convenience of the TELNET interface that
allowed me to connect to the S-100 modem port from anywhere in the house
including my desk in the loft where I usually like to "work". Note: For
XMODEM I use MDM727 on the S-100 system with an overlay based on the easily
available overlay for the Interfacer 4.

b. Next I worked on impementing ZMODEM capability on my Kaypro 10.
ZMODEM was targeted because it is stated to work over connections like
TCP/IP (TELNET) and is faster than XMODEM. I used ZMP15 and the readily
available overlay for the Kaypro, ZMO-KP12. I initially just wanted to get
ZMODEM working and was able to do that with a direct connection at 9600 bps.
Once I had that working I switched to the
S-100 environment.

c. I built an overlay for ZMP15 for the Interfacer 4 that was limited in
capability - most notably it had no re-configuration capability. I initially
set the Interfacer 4 to 9600 bps and tried a direct connection. It did not
work. Next attempt backed off to 4800 bps and that worked. It turns out that
in the ZMP15 documentation the author notes that ZMP15 is unlikely to work
above 4800 bps due to the design of one area that times out after a 100 ms
timing loop. While I might try to tackle that design limitation in the
future, at this point I decided to switch environments. Note: Why ZMP15
worked with the Kaypro at 9600 must have just been due to minor timing
differences in the read or write rotines. The Kaypro is actually a slower
CPU (4 vs 6
MHz) and like the Interfacer 4 does not use interrupts.

d. I moved the NetBurner from the "modem" port to my terminal port that is
normally connected to a Wyse-50 terminal. I then used Hyper Access on the PC
end because it has a nice Wyse-50 emulation. I left that terminal port speed
at 9600 bps. This combination works like a champ. So my S-100 terminal is
now two floors away from the S-100 system and the view towards the mountains
is much better. :-)

e. This left me without a remote connection to the "modem" port for
transfers so I tried a bit different set of hardware. I used a pair of
Parani SD1000 Serial to Bluetooth devices. One is connected to the "modem"
port on the Interfacer 4 and the other is connected to a serial port on the
PC. So one Hyper Access window is the terminal for the S-100 systems and
another window is the "remote" system. I tried ZMODEM across this interface
and it worked well although was limited by the ZMP15 4800 bps limitation. I
also reset the SD1000s to 19200 bps and confirmend that they work with
XMODEM (again using MDM727 on the S-100) just fine with no issues seen due
to transparency imitations. Speed is so-so as one would expect in XMODEM at
620-720 bytes per second. ZMODEM would be faster.


1. I recommend both the NetBurner SBL2e X and the Parani SD1000 devices as
ways to "break the wires" connecting S-100 or other systems to terminas,
other computers, etc.

2. If anyone has a ZMODEM-capable package that will work at 9600 or
19200 (upper limit of Interfacer 4) I would love to get a copy.