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Updating 1980s X Terminals? Answered

Okay, so I've been trying to solve this problem for quite a while now, and I've simply run out of ideas.

In my father's optical store, all of the POS computers are X Terminals. They are all connected to a main server in the back. The server is connected to a device which is kinda like an ethernet hub - on its a box with 16 RJ-45 jacks, and a cable coming out of it which connects to the server's parallel port. Each of the jacks are connected to a small adapter cable (filter? crossover cable?) and that cable has an ethernet cable coming from it into a patch bay on the wall. I'm almost completely sure that the cable is *not* carrying a tc/ip signal, because the back of the hub-box-thing explains that each of the wires in the cat-5e cable are assigned to carry specific parallel port signals. So, I'm pretty sure we have a parallel connection running over cat-5e. Also, I'm pretty sure the server is running red hat Linux, which is running an x-11 emulator. Anyway, from the patch bay, all the signals continue through Ethernet cable until they reach the terminal. There, the cable is plugged into an RJ-45 to parallel adapter, which then plugs into one of the two parallel ports on the back of the terminal.

What I'm trying to do is to replace all of those huge, old and ugly X terminals with newer computers and monitors. I've tried connecting the parallel connector on the adapter to various computers and trying a bazillion programs, but I can't seem to emulate an x-terminal. So, any ideas?

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steveastroukBest Answer (author)2010-12-30

X terminals ? Are you sure ? 1980s generation POS was usually done over RS232 serial. Linux came some time after the 1980s,

Put a screenshot up.

Steve

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aelias36 (author)steveastrouk2010-12-30

Well, *late* 1980s. And, no, I can't take a screenshot. The window manager is super-dumbed-down. (Either that, or I'm just linux-ly challenged.)

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aelias36 (author)aelias362010-12-30

Wait a sec, are you saying I should use an RJ-45 to serial adapter?

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steveastrouk (author)aelias362010-12-30

What terminal are you using ? Show some pictures of the connections on the back.

Steve

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aelias36 (author)steveastrouk2010-12-30

1
I'm not sure at the moment, but it's made by IBM, and I've gotten no hits by searching it up on google.

2
Unfortunately, its about 25 miles away from where I am right now, so I can't get any photos at the moment. I might ask my father to take the pictures to bring back home. Anyway, there's an ethernet cable running from the ceiling down a pillar, into the desk, and up through a hole leading to the back of the terminal. That's connected to an adapter described below:

        Parallel Conector (Only 3 Pins. Weird, huh?)
                       (Plugs Into Terminal)
                   ____|_______|_|________
                   |                                           |
                    \                                       /
                       \                                  /
                          \                             /
                            ‾‾‾‾‾|            |‾‾‾‾‾
                                  ‾‾‾‾‾‾‾‾‾‾‾
                            RJ-45 Connector
                          (Cable Goes Here)

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steveastrouk (author)aelias362010-12-30

Are they perchance pins 2,.3 and 7 in the 25 pin D connector ?????

Steve

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aelias36 (author)steveastrouk2010-12-30

I don't have it with me, but that sounds right! I remember that there were two pins close together on one side, and a third pin on the other side.

You seem to have used 5 question marks. You're on to something, aren't you?

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aelias36 (author)aelias362010-12-30

Wait a sec, those are the send, receive and ground pins, right?

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steveastrouk (author)aelias362010-12-30

Yep. We have it nailed, they're serial terminals, using software handshaking via XON XOFF probably.

Now you COULD use a terminal emulator on a PC, but you have to seriously consider WHY you are doing this. I would have to agree with Frollard, that, apart from the intellectual thrill of chasing these things down, swapping the terminals for something new is a bit of a waste of time, and, from now on, anything that goes wrong WILL BE YOUR FAULT, (even though it isn't)

Dad should seriously consider a new system - things like Adempiere would work well in a commercial sales environment.

Migrating ALL his data is going to be the trick.

If you can, ask for a complete copy of the data files, and see if you can set up a parallel independent system that he likes. If you can, THEN see if he wants to deploy it.

This is a deeply non-trivial problem.

Steve

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aelias36 (author)steveastrouk2010-12-30

(Adding for the fourth time)

I can use these to connect the existing adapters to computers, right?

http://www.amazon.com/Male-DB25-Female-Serial-Adapter/dp/B0016O9L9A/


And then just use something like this?

http://www.chiark.greenend.org.uk/~sgtatham/putty/

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aelias36 (author)steveastrouk2010-12-30

(adding to previous comment)

Oh, by the way, if I *would* want to migrate the data, how should I do that? Or is there no standard procedure?

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aelias36 (author)aelias362010-12-30

(I un-best-answered you so the thread can keep expanding if it needs to. Apparently, having a best answer means no one can comment anymore. If no one writes anything for a period of 2 days, I'll re-best-answer you.)

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aelias36 (author)steveastrouk2010-12-30

Oh, wow! I think I just solved months of frustration in hours! Oh, and see my comment to Frollard.

Thanks a *whole* lot!

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steveastrouk (author)2010-12-31

Yes, those adpaters look fine. I wouldn't mess around with the cheapest serial to USB adapters, make SURE you buy FTDI chipset ones, they aren't the cheapest but they are close to bomb-proof as you can get.

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aelias36 (author)steveastrouk2010-12-31

Um, those are *not* serial to USB adapters. They are DB25 to DB9 adapters.

Also, the reason I didn't respond in so long is because it was 3:55 AM when you answered. I live on the east coast.

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steveastrouk (author)aelias362010-12-31

Yes, I realised that, but I was referring to the 9-25 bits and extending the comment to the USB bits.

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aelias36 (author)steveastrouk2010-12-31

Can't I just use the serial ports on the computers?

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steveastrouk (author)aelias362010-12-31

You still GOT serial ports ? I can't remember the last time I bought one with a native port.

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aelias36 (author)steveastrouk2010-12-31

(Adding to the previous comment)

So I *can* just use this adapter, right?

http://www.amazon.com/Male-DB25-Female-Serial-Adapter/dp/B0016O9L9A/

Also, does the whole lower-price-means-lesser-quality thing still apply to these type of adapters?

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aelias36 (author)steveastrouk2010-12-31

Okay. And you said you made a program? Or could I just use PuTTY?

http://www.chiark.greenend.org.uk/~sgtatham/putty/

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steveastrouk (author)aelias362010-12-31

PUtty will replace exactly what you have, I was referring to getting the old data out of the system.

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aelias36 (author)steveastrouk2010-12-31

Oh, I see.

Are these parameters okay, and if they're unknown to me, can you tell me what they are?

Connection type:Serial
Serial line: COM1
Serial line:[9600, 19200, 38400 or 57600?]
Data bits:[7 or 8?]
Stop bits:[1, 1.5, or 2?]
Parity:[None, Odd, Even, Mark, or Space?]
Flow control: Xon/Xoff

Are the correct answers 9600, 8, 1, and None?

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steveastrouk (author)aelias362010-12-31

Here, you are on "suck it and see" unless you buy a tool.

This is the first analyser I could find

It should help you work it out.

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aelias36 (author)steveastrouk2010-12-31

Okay then. Well, I guess I have the problem completely solved. Thank you *very* much for all of your help! I'll re-best-answer you after there are no new comments for a period of two days, (as stated earlier.) I'm off to a new years party, so you won't be hearing from me until tomorrow.

Thanks!
A.E.

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aelias36 (author)steveastrouk2010-12-31

The machines there are either pretty old laptops that still have all the legacy ports, or mini-towers, which almost always (I think?) have serial ports.

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frollard (author)2010-12-30

May I recommend by any chance - picking up an off-the-shelf point of sale program, and migrating the data -- ditching ALL the original hardware? Very powerful, inexpensive, expandable solutions are available -- and running new hardware on ancient protocols is like having an english to chinese interpreter who operates via snail-mail to send messages to a chinese-to-english interpreter in another part of the same room. It's slow, inefficient, and when something goes wrong, there are WAY too many steps to troubleshoot.

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aelias36 (author)frollard2010-12-30

Although this is usually the best option to go with when upgrading, I don't think it's the way to go. New pos programs have been tried, but they are *less* powerful than the one currently being used. Optical stores call for *very* specialized pos programs, and there are only a few in the market. They aren't exactly a huge industry, so they are generally slow and programmed without the optician in mind.

The current program is *extremely* fast, because there is *no* lag time between any interaction. Also, I'd think that upgrading would actually *increase* the chance of something going wrong, because of the increased complexity and the fact that viruses might be an issue.

So, specifically in this scenario, upgrading the program wouldn't work.

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frollard (author)aelias362010-12-30

hmmm...I can see the conundrum -- why upgrade then?

last option -- does the same company still exist/make a modern version of the same thing?
How much dbase construction and programming would it take for a custom solution?

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aelias36 (author)frollard2010-12-30

Firstly, there are a couple reasons for upgrading:

1. These terminals are HUGE. Even though the screen measures maybe a foot diagonally, it's about a foot-and-a-half deep. We're talking about 1980 crt's in 2011, here! They take away from the desk space, and they give a bad impression to the customers.

2.We have a second machine running windows in each POS anyway.

3.Doing this allows for faster transactions.

Secondly, X-Terminals are *not* manufactured anymore. They have pretty much been replaced with slim servers. The average consumer wants windows, not x11.

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aelias36 (author)aelias362010-12-30

*I meant slim clients, not slim servers*

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aelias36 (author)aelias362010-12-30

Thirdly (I forgot to read that part the first time...), the program itself is actually pretty simple. Although it could be reprogrammed easily, and the database transferred, there's no real point in doing it. If you have the option of hiring a programmer for thousands of dollars or simply buying 15 dollar's worth of adapters, I'm sure the latter would seem better seen fit.

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NachoMahma (author)frollard2010-12-30

.  Where's your sense of adventure?
.  You do make a very good point. The cost of upgrading would be much less than the frustration and downtime of one good incidence.

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NachoMahma (author)2010-12-30

. Googling "x-terminal emulator" turns up a lot of interesting stuff.

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steveastrouk (author)NachoMahma2010-12-30

Do you reckon it will be "X" then Nacho ?

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AndyGadget (author)steveastrouk2010-12-30

I agree with Steve that it's probably RS232 (or RS422), so the box will be a serial port server. Are there any markings on the 'hub-box-thing' to identify it?

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aelias36 (author)AndyGadget2010-12-30

Yes, there are markings. It's not exactly with me at the moment, but I'll get a picture of it.

So, are you saying that I have an RS232 (or 422) connection running over cat5e being terminated with a *parallel* jack? To me, that sounds a bit bizarre. Although, of course, You're definitely on to something.

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NachoMahma (author)aelias362010-12-30

> *parallel* jack
.  Just a wild guess, but could that be SCSI?

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aelias36 (author)NachoMahma2010-12-30

(adding to previous comment)

Then again, I've never inspected the connector to see if it has that little logo above it.

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NachoMahma (author)aelias362010-12-30

.  Judging by other comments, it may be a DB-25.
.  SCSI was most famous as the peripheral i/f for early Macs. One of the SCSI connectors looked a lot like the Centronics connector used for many parallel printers.

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AndyGadget (author)NachoMahma2010-12-30

. . . and the centronics printer interface was based on the IEE488 interface which was a general purpose parallel interface for connecting equipment.

If there's any part numbers on the box we should be able to track down *exactly* what it is immediately.

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aelias36 (author)NachoMahma2010-12-30

I'm almost completely sure its db-25.

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aelias36 (author)NachoMahma2010-12-30

Oh, no, it's not. Isn't that used on older printers?

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aelias36 (author)AndyGadget2010-12-30

Adding for the third time, I think you've got it. A quick look at the RS-323 pinout shows the name of all of the pins, and those *same* pin names appear on the back of the box, (which, I guess, can be rightfully called a serial port server.)

So, back to the main question, would the right thing to do be to get an RJ-45 to Serial adapter?

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aelias36 (author)AndyGadget2010-12-30

Adding to my other comment, this would make a lot of sense, because there are only 3 pins on the parallel-jack-side of the adapter.

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steveastrouk (author)AndyGadget2010-12-30

I'm looking at the putative age and thinking 422 ? Then ?

Steve

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NachoMahma (author)steveastrouk2010-12-30

. I don't know. But I think you're on to something with RS-232.

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