IBM

I've had this thing kicking around for a while. Over time I gathered up some twinax terminals here and a few lengths of twinax cable there and now again I'm curious what exactly can be done here. Kjaer's being tight lipped on me. It's either because I'm insane to fiddle with twainx while lacking ANY AS/400 gear...or I'm plain insane to begin with.

That however is my question. While this is just a multistation twinax terminal controller the main system interface is from what I read an RS-232 (x.21 and x.25 compatible) port that talks in EBCDIC.
Is this REALLY only compatible with OS/400 and I series? Nothing from AIX? Not even from Linux?

All the IBM docs have the 5394 firmly in the "I" camp (AS/400). It's very likely to only work with AS/400s (and you don't want to go there unless you get an absolutely complete AS/400 including software or have good friends at IBM).

Lovely.

I've wanted to play with an AS/400 or System i machine for awhile, and my POWER6 could run System i, I guess, but it's going to wind up being an expensive, heavy doorstop since my workflow is heavily Unix centric. So the POWER6 runs AIX.

I simply can't see myself doing ANYTHING with an AS/400.

Neither can I. And it's sad, because those systems do some heavy lifting.

AS/400 had some neat ideas, but they're so difficult to lay hands on (complete with OS/400) used at hobbyist prices that nobody's really had the opportunity to figure out what can be done with them (beyond DB stuff). My suspicion is that OpenVMS would be in the same boat (MPE certainly is), but for two things: it's more accessible and OVMS's former penetration of academia exposed more people to it than AS/400's "backroom commercial" market.

The system seems to work for IBM, though. They don't "look the other way" for OS/400 the same way they do for AIX.

Tight lipped? I told you that this was absolutely, utterly useless without an AS/400 host. You chose not to believe me. There wasn't much else to say.

It just seems so absurd, that's all.
A serial communications device that only works with one lump of software. No alternatives and no open-source projects.


....But okay, I'll take your word.

pentium wrote: It just seems so absurd, that's all.
A serial communications device that only works with one lump of software. No alternatives and no open-source projects.

Welcome to the World of IBM. Yep, it only works with one machine - but you can bet that it works very well with that machine.

The lack of open-source alternatives is a result of IBM's "two minds" - some things they're very open about, other things Klaus Fuchs probably couldn't get his hands on if he tried. Most of the second category is the mini-and-mainframe stuff.

pentium wrote: I've had this thing kicking around for a while. Over time I gathered up some twinax terminals here and a few lengths of twinax cable ...

I should throw rocks at you.. I had the misfortune being exposed to one of these many years ago

Ryan Fox wrote:

pentium wrote: I've had this thing kicking around for a while. Over time I gathered up some twinax terminals here and a few lengths of twinax cable ...

I should throw rocks at you.. I had the misfortune being exposed to one of these many years ago

Let him who is without 5394s (or other specialized IBM hardware) throw the first stone.

There are those who would say that being stuck with one of these type of things that they need to get working and absent the budget to get IBM support is sufficient punishment.

pentium wrote: I simply can't see myself doing ANYTHING with an AS/400.

What, does ERP-at-home not appeal to you?

thread hijack...
http://www.ebay.com/itm/NuBus-Twin-Axce ... 0962679781

Clearly not a video card, this is a biphase communications processor for use with 3270s and 5250s. I don't know the pinout of the DA-15 connector but maybe it can talk to a 5394.

The wiring is different, but the modulation is very similar (although the protocol is different). The DP8344B datasheet shows the connections: 3270 cables are transformer-coupled, 5250 cables are driven from balanced current-mode amplifiers. The card requires adapter cables.

I've only know of Apple's in-house built twinax card. I've only seen it ONCE and apparently they DID sell them but they were obviously not a hot seller.
I'm pretty sure one of IBM's twinax cables for their own cards and terminals will work fine with that card but if it isn't the Apple card I have no idea where you could find extensions.

robespierre wrote: The wiring is different, but the modulation is very similar (although the protocol is different).

That sounds like a description I once read of the difference between RS-232 and current loop. "They are very similar but totally different"

yeah that sounds about right. you can convert rs232 <-> 20mA with a simple circuit that uses optoisolators and emitter followers.