View Full Version : 3Com Etherlink II upgrade - Is it worth it?

May 22nd, 2012, 05:28 PM
So I have an IBM XT with a 3Com Etherlink II and an AUI to RJ45 transceiver. I was wondering if there is a big enough speed difference in a network card with rj45 built in to trade the Etherlink II for one.

May 22nd, 2012, 05:44 PM
I wouldn't bother. Might be handy not needing a transiever, but no matter what you do it's still going to be slow. Even on serial port transfers my host has to wait for the poor XT to catch up.

What transfer speeds are you getting?

May 22nd, 2012, 05:46 PM
None, yet. I haven't loaded the packet driver yet. I am about to purchase a cdrom drive and controller so I can transfer files from my laptop.

May 22nd, 2012, 05:49 PM
2 X Serial Port or 2 X Parallel Port + Laplink = easy transfer.

May 22nd, 2012, 05:54 PM
Well, my laptop doesn't have a serial port and I have heard of problems with usb-to-serial adapters. Plus, I just found a huge stack of CD-RWs and want to use them.

May 22nd, 2012, 07:06 PM
That ancient CD-ROM drive (assuming its a Panasonic/Mitsumi/Sony interface since I know they have 8-bit cards) isn't going to read CD-RWs.

May 23rd, 2012, 02:51 AM
The drive is an SCSI NEC 6x Multispin Caddy loader. Will it read cd-r if it is already written to?

May 23rd, 2012, 05:44 AM
It should do, disc-at-once would be safest. Note CD-R, not RW.

Shadow Lord
May 23rd, 2012, 12:23 PM
So I have an IBM XT with a 3Com Etherlink II and an AUI to RJ45 transceiver. I was wondering if there is a big enough speed difference in a network card with rj45 built in to trade the Etherlink II for one.

I have three of these in my systems (one in a 5150, a 5160, and a 5155) and they are great.... if you really need 8bit NIC w/ Ethernet connectivity. I basically have all my systems tied into the main house LAN. On the server I have a share setup for just these old systems and I have my disk images and files there. So no need in figuring out how to get a program from one system to another! ;) But don't expect to be streaming any videos any time soon! ;)

Speed wise the Etherlink IIs will all perform the same. Your AUI should not make a difference at all. Of course it is a big piece of plastic that is sitting somewhere so for neatness sake a native Ethernet port might be better (my reasoning when I bought my cards plus I got three NOS cards for $12 each so it was an easy decision).

May 23rd, 2012, 02:11 PM
You can also get an old 3com home office hub that had AUI, coax, and cat5 as a bridge between the older machines that use coax.


May 23rd, 2012, 02:22 PM
Just curious... What would happen if I connect one end of an rj45 cable to my laptop and the other to my old PC?

May 23rd, 2012, 02:26 PM
Like serial, when you connect machines directly you need to swap a few wires, but some adaptors can detect this and switch around automatically. Normally you'd actually buy a Crossover network cable (network version of a null modem cable).

May 23rd, 2012, 02:29 PM
Well, assuming one of the random cables I have in my box of parts upstairs is that what software would I need/how would I use this?

May 23rd, 2012, 02:35 PM
Update: When I connect the XT to my laptop, the twisted pair transceiver says there is a link, but Windows 8 just says "Identifying".

May 23rd, 2012, 02:35 PM
Going direct with a crossover cable is the same as going through a hub, just without the hub, nothing special to do.
You don't really see crossover cables very often, since most network hubs/switches/routers have an Uplink port for this purpose, but you can still buy them new (or make them).

Just remember things like your router which normally provide DHCP etc wont be available - so set up static IPs etc.
What method were you planning to use to transfer the files? FTP?

Edit: in reply to above, yeah you need a crossover cable by the sounds of it
Edit2: actually if Windows is looking for a DHCP address... try a static IP

May 23rd, 2012, 02:38 PM
Wait - I don't think this is a crossover cable, but I do have a wifi router. If I connect them both to it directly will it work like a crossover cable? Also, how do I make one?

May 23rd, 2012, 02:50 PM
yeah just use the router if it's not an issue.
And yes hubs/routers/switches do the crossover for you, thats why you rarely see crossover cables.

Pinout info is on wikipedia at http://en.wikipedia.org/wiki/Ethernet_crossover_cable and all over the internet. Just need a crimper, connectors and some CAT5/5e/6

I still think, even with a USB adaptor, LapLink/FastLynx 2 are much easier though.
How were you going to use the network? FTP?

May 23rd, 2012, 03:19 PM
Honestly, I have no idea. I just now thought of using rj45 and hoped it would work similar to a laplink connection.

May 23rd, 2012, 04:57 PM
There are also Intel and I think cisco routers with the same basic rj45+aui+bnc connections... I happen to own one, paid a whopping 4.99 for its 32 port goodness! ^_^

May 23rd, 2012, 05:11 PM
Honestly, I have no idea. I just now thought of using rj45 and hoped it would work similar to a laplink connection.
It will kind-of work like that if you install an FTP server application on your laptop, and install mTCP on your XT (configure it, and use FTP client). You'd then open the FTP client, connect to your laptop via an IP address, and be able to download/upload any files to the hosted directory. If you can get mTCP on the machine and installed, then this is a good option because you've already got the hardware/bits.

One advantage to serial (either with Fast Lynx 2 or LapLink) is you do not need to copy any software first, you can install via the cable using one or two basic DOS commands. Good link for a 'how to' with serial is http://www.minuszerodegrees.net/transfer/laplink3.htm which has a section regarding the USB adaptors. You may have already read it but if not, it's a good read.

Hope that helps.

Edit: mTCP linkage http://www.brutman.com/mTCP/

May 23rd, 2012, 06:07 PM
Oh, I was hoping it would be something really similar to the minuszerodegrees tutorial, except instead of this:
mode com1:2400,n,8,1,p
in DOS, you could somehow refer to the network adapter instead of com1.

May 23rd, 2012, 06:36 PM
Unfortunately not, networks are a lot more complicated and DOS doesn't really have any built in support for them.
Only standardised communication ports that don't need drivers in DOS are really COMx (serial) and LPTx (printer).

Trouble is each network card needs it's own drivers to initialise, and then there are different network standards e.g. Ethernet vs Token-Ring, and different protocols IPX and TCP/IP etc, and the machine needs to know how to request something from one of possibly many machines. So DOS (which is quite small) really can't make use of any of it until you've installed a bunch of software to tell it what to do.

May 24th, 2012, 12:02 AM
Ethernet is a lossy shared media packet based standard. So as said the OS needs the rest of the network stack to function by finding target (MAC) addresses, splitting data into packets, coping with packet loss.

One of the simplest protocols is NetBEUI, supported by Win2k3 but not sure about Win7. Obviously if you run IPv4 everywhere it will work, with static addresses unless you have a DHCP server also attached to the network. IPv4 is quite heavy for an XT though. Re the original question, media converters don't affect performance.

May 24th, 2012, 02:29 PM
IPv4 is quite heavy for an XT though.

I beg to differ ...

An XT (or any early x86 based machine) has more than enough CPU power to run TCP/IP. I've measured send and receive rates from 70 to 100KB/sec depending on the network card being used. That's enough to fill the memory a maxed-out machine (640K) in well under 10 seconds, so it doesn't just work - it works with pretty good performance.

Remember, TCP/IP was mostly designed before the XT. The original target machines had better I/O capability than an XT, but comparable (in the same neighborhood) CPU abilities.


May 24th, 2012, 03:37 PM
Its an XT, not like you are going to multitask when doing file transfers over the network.

Shadow Lord
May 24th, 2012, 04:06 PM
Its an XT, not like you are going to multitask when doing file transfers over the network.

What you don't run Doom while copying files in the background on your XT over a LAN? ;)

May 24th, 2012, 04:12 PM

Depends on the application I guess.
I consider the Microsoft TCP/IP driver to be very memory heavy (no idea about CPU usage), but that's only relevant if you were going to run MS LanManager/Client. I never got NetBEUI to work, my W2K Domain Server just refused to authetnicate over NetBEUI.

May 24th, 2012, 11:15 PM
That was my point, that TCP/IP typically has more overhead in general that say NetBIOS so is less preferably for a machine with such limited memory & CPU. There's no need to carry the weight of a routable protocol for what is bound to be a single-segment link.