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Program to Transfer Files from Modern Machine to PC

After some serious trial and error, I finally got the terminal programs (Hyper Terminal & Telix) working and I sent files from the Win XP machine to the 5150 using the Zmodem protocol. I tried it at 2400, 4800 and 9600 baud, but it would only work reliably at the lower two speeds. I also had to turn the FIFO buffer off in the Win XP machine. With 9600 baud, if I tried to transfer a file of any size (say 64K), I would receive bad packet errors and the connection would eventually timeout.

Unfortunately, my 5150 serial cards are all 8250 UART based, so 9600 would be the maximum transfer rate I could get. I am not sure whether faster cards, based on the 16450 or 16550 UARTs, would work in the 5150.

9600 should work, both machines support that transfer rate. I wonder if the cabling is too long from one machine to the other. Would a shorter cable improve reliability?
 
On a 5150 class machine using an 8250 UART the BIOS supports a maximum of 9600 bps. But with careful programming faster rates can be used. The careful programming includes not doing screen I/O, not polling the keyboard very often, etc - you are trying to poll the serial port for incoming bytes as quickly as possible, and those other things take time. The 8250 UART only has a one character buffer. There were many programs that adjusted the divisor rates for the UART themselves to get faster speeds.

Serial should be good for many tens of feet. If you are under 10 feet and it is a reasonably good cable then I would not worry.
 
I just tried it on my Win 9x machine (still using Hyper Terminal) and eliminated a USB cable and USB-to-Serial adapter. 9600 baud is still giving me "subpacket too long" type errors with Telix, leading to timeouts.

But with careful programming faster rates can be used. The careful programming includes not doing screen I/O, not polling the keyboard very often, etc - you are trying to poll the serial port for incoming bytes as quickly as possible, and those other things take time. The 8250 UART only has a one character buffer. There were many programs that adjusted the divisor rates for the UART themselves to get faster speeds.
Click to expand...

Do you know if Telix is one of them? Perhaps Hyper Terminal is not the best Windows program to make such transfers from the machine.

I will also try using a true IBM Asych card instead of the Six Pak Plus card I have in the machine now.
 
Maybe it's time to step back a notch or two.

If this were my setup, I'd probably, as another poster has said, transfer the files via CD-ROM (scsi adapter). But I understand that you may not have that.

My next choice would be floppy or zip drive.

You can get the files to a Win9x machine--great! That also means that you can shutdown to a DOS prompt on it and not have to deal with the Windows drivers.

Isn't there a version of LapLink that runs on a 5150 via parallel port? That would be the next choice after that.

Finally, I'd probably just grab an old copy of Qmodem or Procomm from the Simtel library and use it on both ends (but I would do this on the Win9x machine with real serial ports, not a USB adapter). The old versions were well aware of the limitations of the old systems and are worth a try.

If you can rig up serial ports with hardware handshking, so much the better. The receiving machine can then tell the sending system when it's safe to transmit.
 
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You might look for a small utility called ZIP 2.21. I never tried it on an XP machine, but the only requirements are it must be installed on both machines and it connects through a null-modem cable.
 
Don't forget that the 16550 has the broken FIFO and you need to get the later version if you want to make use of that. :)

Anyway, something doesn't add up here... unless I missed something again. Since you say you have paralell ports on both machines, and those should work at 115200, why aren't you using those???
 
Telix & Hyperterminal

Telix & Hyperterminal

Have you tried any other of the older file transfer protocols, such as XMODEM or Kermit ? Hyperterminal supports them, don't know about telix.
Have you played around with handshaking at all ?
And, last and least, on the 5150, do you have any drivers loaded for anything that might be slowing things down ?
I'd try booting with no drivers first, to see if it works any better.
patscc
 
When I used the IBM Async card, I was reliably able to transfer at 9600 baud between the 5150 and the modern machine. I had also reformatted the hard drive, but only had 256K in the machine (as opposed to 640K earlier). The only driver I have loaded is ANSI.SYS.

For the files I need to transfer, 9600 will do. I might even try zip again.
 
Chuck(G) said:
Isn't there a version of LapLink that runs on a 5150 via parallel port? That would be the next choice after that.
Click to expand...
The suggestion of Laplink for old computer to new computer transfers has been made a few times on these forums.

One problem is that Laplink requires the use of computers that are running at a similar speed. For example, if I connect my 6 MHz 5170 up to my 486DX-66 clone (via serial or parallel Laplink cable) and start transferring files, I find that after about a minute, Laplink goes into perpetual 'timeout' (continually displays 'timeout'). If I then switch the 486DX-66 out of turbo (goes to 8 MHz), then restart Laplink at both ends, all goes well. Others on this forum see the same problem.

The other problem I've come across, which I haven't seen written about on these forums, is that I can't get different versions of Laplink to communicate at all. So for example, I can't get Laplink 3 to communicate with Laplink 4, and I can't get Laplink 4 to communicate with Laplink 7.5 (for Windows 95). It's as though the authors have made changes to the transfer protocol at each version, dropping support for the earlier protocol. And so the idea of using an old version of Laplink on the old computer, and a newer version of Laplink on the new computer goes out the window. It may not have worked anyway because of the earlier described 'speed' problem.
 
Great Hierophant said:
For the files I need to transfer, 9600 will do. I might even try zip again.
Click to expand...

Yes, I remember in the day that 9600 was regarded as blazingly fast. Unless it's a huge zip archive, most PC files of that vintage are pretty small and don't take that long to transfer at that rate.

I used to do a lot of file transferring from an NEC 8201a to an IBM PC back in 84-85. I used 2400. Although 9600 (and perhaps even higher) was available, 2400 was very reliable and didn't take very long for the 25k or so text files I often transferred.

I loved that little NEC 8201a. The diamond cursor key arrangement was so much more sensible than the TRS-80 Model 100, and made editing quick and easy.

I'd love to own one again, just for nostalgia's sake.

Tez
 
file transfer freeware

file transfer freeware

I stumbled across yet another DOS serial port file transfer utility, which I'm attaching in case anyone wants to try it. It does start up under XP's command prompt, but at the moment I can't try to transfer.

patscc
 

Attachments

  • link.zip
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