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View Full Version : Can the ST us a CentreCOM 210T tranceiver??



NathanAllan
October 9th, 2006, 12:03 AM
The part is not vintage, but I wanna use it on the Atari ST if at all possible. To get a good look at it do a google or ebay search and there's a bunch of them.

So what the heck can I do with it? Can it be wired to the serial or parallel port? Or both? I can't find much about a workstation with an AUI port anywhere, only things that connect to them, like this tranceiver. Or hubs, or cables or whatever, but no actual workstations or anything (correct me if I'm wrong and don't really know what I'm looking at).

Nathan

modem7
October 9th, 2006, 02:50 AM
In the early days of Ethernet (before 10Base2 [thin coax]), you had a thick coax cable (10base5) running through the building and through the ceilings. Computers and workstations didn't connect directly to that thick coax. As required, boxes commonly known as multiplexers tapped into the thick cable (either directly or indirectly). Your desktop computer or workstation had an AUI port and you used a long AUI cable to connect your AUI port to one of the AUI ports on the multiplexer.

Workstations (such as the Sun 3/60) usually had the AUI port as a standard port on the rear of the machine. Desktop computers (such as the 5150/5160) usually needed to have a network card fitted.

The CentreCOM 210T tranceiver was a very common AUI/10BaseT transceiver. Such transceivers were mostly used to connect older network equipment (such as old Cisco routers) to more modern network equipment.




┌───┐
│ │ Terminator
└─■─┘
║ ┌────────────────────┐
║ │ │
┌─■─┐ │ │
│ ║ ├───────────────┤ FILESERVER │
└─■─┘ │ │
║ │ │
║ └────────────────────┘




┌───■─────────────────┐1 ┌─────────────┐
│ ║ ├──────────────┤ workstation │
│ ║ │ └─────────────┘
│ ║ │2 ┌─────────────┐
│ ║ MUX ├──────────────┤ workstation │
│ ║ │ └─────────────┘
│ ║ (Multiplexer │
│ ║ Box - │ ↑
│ ║ contains 8 │ ↓
│ ║ transceivers) │
│ ║ │8 ┌─────────────┐
│ ║ ├──────────────┤ workstation │
└───■─────────────────┘ └─────────────┘




┌───■─────────────────┐1 ┌─────────────┐
│ ║ ├──────────────┤ workstation │
│ ║ │ └─────────────┘
│ ║ │2 ┌─────────────┐
│ ║ MUX ├──────────────┤ workstation │




↓ Ethernet Cable





┌─■─┐
│ │ Terminator
└───┘

mbbrutman
October 9th, 2006, 06:37 AM
Another interpretation:

If you look at an Ethernet card there are three possible types of connectors:


AUI/DIX: DIX stands for Digital, Intel and Xerox and it refers to the signals coming out of the port. AUI refers to the DB-15 port. This connector is used with an external 'transceiver'.
BNC: This connector is used with 'Thin-net' cabling
RJ-45: This is the familiar RJ-45 8 pin connector that most of us are familiar with today.


AUI/DIX is the oldest type of connector, and it dates back to the very origins of Ethernet. Back then, the 'Ether' was a big cable and the transceivers were attached directly to it. The transceiver was responsible for detecting the carrier and collisions, and sending and receiving the raw data.

Thin-net was a big improvement on the cabling. It was a smaller cable, and easier to hook up to. Instead of piercing the 'Ether' to attach a transceiver, you used BNC connectors and T adapters. Also, by this time the electronics were small enough to integrate on a card.

RJ-45 was the next connector type, and it carries the signal over telephone type wiring. The wiring is 'twisted' to prevent cross-talk on adjacent wires. Not all cards with RJ-45 ports use the standard Ethernet twisted pair signalling and voltage levels! Some manufacturers had their cards and switches out before the standard was approved, so there are non-standard ones out there.


Some examples of cards and hookups ..

My Western Digital 8003 card has a DIX/AUI port and RJ-45. I thought I was in luck with the RJ-45, but my hub wouldn't light up when it was connected. It turned out that the RJ-45 was non-standard signalling (Lattisnet), so I wouldn't be able to use it. So instead I added a Centrecom AT210 to the card. The Centrecom is a transceiver that goes from AIU/DIX to standard twisted pair wiring. As far as the Western Digital card is concerned, it just knows it has an external transceiver .. how the signal gets out really doesn't matter. See http://www.brutman.com/PCjr_WD_small.jpg for a picture.

My NE1000 cards and 3Com cards have just BNC and AIX/DIX connectors. That gives me a choice of Thin-net or using external transceivers to go to untwisted pair again.

In case I ever want Thin-net in the house instead of twisted pair, I have a few Centrecoms that have an BNC output instead of an RJ-45 jack. :-)

Something to keep in mind ... This all presumes that you started with an Ethernet card. If you don't have an Ethernet card with an AUI/DIX connector, Thin-net, or RJ-45, none of this applies.

If you want to attach a machine that just has a parallel port to an Ethernet network, try a parallel-port to Ethernet adapter such as the Xircom PE3-10BT. For non-PC users the Xircom is a disappointment because it doesn't have technical specs freely available, so writing your own software to use it is close to impossible. Go for the Dlink parallel-port to Ethernet adapters instead - they were supported under Linux, so the technical specs for talking to it are available.

NathanAllan
October 9th, 2006, 06:58 AM
Well, I totally forgot about that third connector on the back of some ethernet cards. So it's not useable with the atari, as there is no port like it, not usable y a parallel port 'cause the port is not wired the same. Now I know. Thanks y'all.

mbbrutman
October 9th, 2006, 07:50 AM
There are other Ethernet solutions out there. If you can get Ethernet on a C64 you can certainly put it on a later Atari.

Older Ethernet hardware like the NE1000 is dirt simple - it just requires a few I/O ports to talk to. No DMA or IRQs. That hardware would be fairly easy to graft onto any machine. Software would be tricker .. I suspect that writing the code to initialize the card and do data transfers is beyond what most of us here viewing want to attempt.

NathanAllan
October 9th, 2006, 08:50 AM
I'm looking for a cheaper-type solution, really. There are a few ethernet implementations for the ST, the latest that I know of being the NetUSBee, a cartridge that has ethernet and USB on a cart, but then you have to get new ROMs to use it.

http://hardware.atari.org/netusbee/index.htm

I've been following the thread over at atari-forum, but as far as I know it's not for sale yet. There's also a serial to ethernet, though the name escapes me for the moment.

/edit The thing I couldn't remeber is the Lantronix UDS-10, serial to ethernet device.

carlsson
October 10th, 2006, 12:15 PM
As a side note, I read that the UDS-10 will be discontinued, in favour of a newer, better model but still functioning with old hardware.

NathanAllan
October 10th, 2006, 03:01 PM
As a side note, I read that the UDS-10 will be discontinued, in favour of a newer, better model but still functioning with old hardware.
I saw that, and hopefully they'll get cheaper in light of the newer-better-shinier model. Or things will change for me and I can get the new model. Who knows. But I'll hold out for the reallycool multi-use device. Only thing I'm concerned about is device drivers for an Atari ST.

DimensionDude
October 10th, 2006, 06:53 PM
I have a UDS-10 and haven't done much with it, but I do have a little knowledge of how it works.

You can, for example, connect it to your ethernet LAN. The setup of the UDS is via ethernet, although it can be accessed through the serial port. It can be set so that the computer (or other serial device) it is connected to will see it as a modem. Therefore, all you would need then is a terminal program.

Kent

NathanAllan
October 10th, 2006, 07:12 PM
I have a UDS-10 and haven't done much with it, but I do have a little knowledge of how it works.

You can, for example, connect it to your ethernet LAN. The setup of the UDS is via ethernet, although it can be accessed through the serial port. It can be set so that the computer (or other serial device) it is connected to will see it as a modem. Therefore, all you would need then is a terminal program.

Kent
THAT just made things easier! Yep, I think I want one, discontinued or not! :D Setup via ethernet. Who woulda thunk it. Time to break out the data switch so I can hook up the Headstart(once it's working), the PS/1 AND the ST or just both ST's!

NathanAllan
February 15th, 2007, 09:25 AM
Schoolwork is making me want to get an ethernet router for practice at home (one hour twice a week is just not enough to learn about routers) so I found one on ebay for cheap. It's older but it speaks the same language and is about the same model as the class uses. PLUS it has an AUI connector on back and NOW I get to use my AUI adapter!

And I can still use the atari via the serial port to configure it.

Since I'm getting a rack mountable router, I have conviced my wife to let me build a wooden, stylish rack in the bedroom. I'm gonna stack as many machines as I can on that rack and free up some hallway space.

Nathan