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getting rid of dumb terminals

By mike.kl ·
Hi, i hope someone can assist. We have approximately 20 dumb terminals at our office connected to an old ibm controller (3174 I believe) then to a router and a dedicated link which goes back to our client located in a different part of the city. We would like to replace these dumb terminals with pcs, have those pcs on our own internal network (to maximize their use) but still be able to access the clients mainframe (I guess we would have to use some terminal emulation software??). And I guess we'd have to make a connection from our internal lan to the router? What is the best way to do this with the least cost? Would we have to purchase only software and make configuration changes on both ends? What would the client have to do? Or would we have to purchase additional hardware?

Thank you all.

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by CG IT In reply to getting rid of dumb termi ...

dumb frontends huh so what does the clients mainframe run Unix? thats the biggest hitch is finding out what protocol and applicationyou'll need to run on the PCs to talk to the mainframe. as long as you know which protocol to run and if the application that needs to run is compatible with Windows [or requires legacy support ].

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by In reply to getting rid of dumb termi ...

Hello Mike...

This is a dinosaur question :-). As you already know, the answer to your question is not simple, but there is an answer.

- Firstly, "dumb terminal" is an old term that applies to character-based terminals that merely send and receive a stream of ASCII bytes. You must be using IBM 3278 terminals. They're dinosaurs, but they're not dumb.

- A modern IBM mainframe and PC client configuration would have the mainframe accept 3270 terminal connnections over an IP network. Both the mainframe and the PCs would be connected to IP networks. Routers would join the networks so the two can communicate.

- Some models of modern 3174 controllers can support ethernet and LAN connections. So, your router could be routing IP packets. But, since you're using old 3278 terminals, I doubt this is the case. You likely have an old 3174, and old-style synchronous SNA network, and your mainframe router is not routing IP packets (may not even be capable of it). Is this correct?

- If the above is correct, you could replace the 3278 terminals with PCS without making any other hardware changes. The PCs would have two additions beyond a normal PC: (1) A 3278 coax card, and (2) 3278 terminal emulation software. You would connect your existing 3270 coax cables to the 3270 coax cards instead of the existing 3278 terminals. There would be no hardware changes on the mainframe or the mainframe SNA network. This probably sounds appealing. But, 3270 coax cards are a special-purpose technology investment and they are relatively expensive at over $400 each.

Does this help?

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by In reply to

Q: Can someone tell me what actually has to be done on it to allow connections via IP?
A: Usually, in a modern IBM mainframe that accepts IP 3278 terminal connnections, the front-end communications controller must be of such a model that can be so-configured. It's really too deep of a discussion to explain it all here. The datacenter IT staff need to get in contact with their IBM sales reps, discuss, and work out what additional mainframe-side equipment must be acquired, installed, and configured.


Q: And wouldn't software like Attachmate Extra allow the new pcs to connect to it (given the proper config was done on the router, etc) or would there have to be an intermediary device like a new server..?
A: Yes. Attachmate Extra would be exactly what you would need on the PC client side in order to connect to a mainframe that accepts IP 3278 terminal connections. Of course, in order for your PCs to actually connect, you'll need the appropriate IP network components to get there. That could be a dedictated IP comm link between the two buildings with routers at each end. Or, it could be an Internet connection at each site with a VPN server. Or.... There are many possibilities here. A server that performs a "gateway" function is also one of them. But, this is not necessary.

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by mike.kl In reply to getting rid of dumb termi ...

Thank you for your replies. We thought about using coax cards but the costs were too high. The mainframe is hosted at a remote site. Can someone tell me what actually has to be done on it to allow connections via IP? I have no familiarity with mainframes at all. And wouldn't software like Attachmate Extra allow the new pcs to connect to it (given the proper config was done on the router, etc) or would there have to be an intermediary device like a new server..?


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by Info-Safety, LLC In reply to getting rid of dumb termi ...

Actually, this is not at all that difficult. If you install TCP/IP on the IBM, you can use 3278 emulation software on the PCs to connect. One good product is QWS3270 Plus, from Jolly Giant software.

This is the commercial version. You may still be able to find the freeware version of this software, but it is not as nice.

Good luck.

Craig Herberg

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by dplewis In reply to getting rid of dumb termi ...

Everyone's been on the right track but you have the following issues:
Tn3270 would seem to be the easiest way of doing this. The Attachmate software you mentioned is capable of this, but there's many other options (I've used Reflection with some success).
Your host needs to have TCP/IP support. Most importantly, the Apps on it need to support TN3270 access (shouldn't be a problem - TN3270 is very similar to 3270 emulation).
Your host needs to have IP network connectivity - this could be via a 3746 FEP, a 2216 Router or a big Cisco router. In most cases these would be channel-attaced. I think some hosts also support direct LAN attachment (i.e. Ethernet). You'd then need ethernet support for your PCs and a LAN, WAN or both, capable of carrying the IP traffic between clients and hosts.
Basically you need to talk to someone who specialises in this. Most importanty, you need to enlist the people who look after your mainframe, to find out what it can and can't do now.

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by wlbowers In reply to getting rid of dumb termi ...

A lot will depend on what you are doing on the mainframe.

Are you accessing a database, running applications, updating software.

As some have said there are hardware and software solutions for you. Both will require some mods on one or both ends.

With a dedicated link you have more options that you would have if you had to dial in.

A little more information will get you a lot more options.


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