• Please review our updated Terms and Rules here

Can't get File Maven null modem program to work via parallel port

Bill-kun

Bill-kun

Veteran Member
Joined
Nov 2, 2020
Messages
686
Location
Michigan
File Maven is a very good modern DOS program for null modem file transfers. I've successfully connected several of my computers to each other (no more than 2 at a time) for file transfer. All have been by serial port, though, because I have yet to get File Maven to connect any two computers by parallel null modem. I am using DB25 cables, and a DB25 null modem adaptor.

It's not necessary that I use parallel, but after trying between 4 different vintage PCs, and none of them will connect that way, I am wanting to find out why. Maybe I can even "fix" it so it will work.

Does anyone have any success in using File Maven in parallel connections?
 
Null modem is serial. You will not be able to use a serial cable to connect two parallel ports.

I’ve never heard of file maven, but most programs will use a laplink parallel cable. I’ve got a Symantec pcanywhere cable that works too.
 
From the FAQ:

I am unable to get the PARALLEL connection to work. What should I do?
Make sure you have a true parallel transfer cable and not a plain parallel cable. Transfer cables have their transmit/receive and handshaking wires crossed. They are sometimes referred to a "LapLink" cables. This can be checked with a multimeter device against the parallel pinout chart.

Next, try connecting in 4-bit mode by unchecking the 8-bit setting on both PCs under Configure/Link/Parallel. Many modern PCs use advanced ECP/EPP parallel ports that will not support 8-bit transfers. You can use an 8-bit cable in 4-bit mode but you cannot use a 4-bit cable in 8-bit mode. Also check under Configure/Link/Parallel/Port on both PCs to make sure the correct LPT ports are selected.
Click to expand...

Got it? LapLink parallel cable. Also works with MS Interlink, Norton and other transfer programs.
 
Right, I now remember the pinout diagram. Thank you for the reminder. I checked the pinout diagram versus the 25-pin null modem adaptor I have (continuity via multimeter), and they do not match.


I'll either find a DB25 Laplink cable on eBay, or I'll get a project box, small breadboard and some wires, and DB25 connectors, and make my own. I think I'll make my own transfer box that way; it would be a great experience.

So, the DB25 null modem adaptors that I have are for 25-pin serial ports, not parallel ports?
 
Last edited:
Bill-kun said:
I'll either find a DB25 Laplink cable on eBay, or I'll get a project box, small breadboard and some wires, and DB25 connectors, and make my own. I think I'll make my own transfer box that way; it would be a great experience.
Click to expand...
See [here]. I made those up donkeys years ago; parallel Laplink on the left, serial Laplink on the right. Plug into one of the computers, then extend using a 25-wire DB25 ribbon cable.
 
The LapLink cable arrived in the mail today. It works great in 4-bit mode in File Maven. Using it in 8-bit mode almost works; the host computer appears to have all of drives A-Z active plus more ASCII characters after Z. Trying to select any of the drives results in an error.
 
Generic parallel Laplink cables are 4-bit beasts. They also work with Microsoft Interlink and Norton's (whatever it was called). Few early PC-compatibles had EPP or ECP capability. One first saw it in the PS/2 line.
 
So—cut of curiosity—what would an 8-bit LapLink cable be? I see the 8-bit parallel wire mapping table on File Maven’s help site. I tried making my own using a breadboard, 2 breakout connectors, and a lot of short wire pieces. Something must not have been connected properly, though, because there was never acknowledgment of a connection. Or the computers I was using it with (a KLH 195/286 and a JPL 386) were not advanced enough to recognize it?
 
It's a big maybe. Your system has to support it. You can get a clue in the BIOS setup. If there's a choice in there of "Legacy/EPP/ECP", then 8 bit transfers are supported. File Maven's 8 bit cable is detailed here. AFAIK, there was no standard common 8-bit cable connection--and even when supported, was a bit twitchy. If you want to get deep into the ECP/EPP technical end, check out the Wikipedia page on IEEE 1284.
 
You must log in or register to reply here.
Back
Top