AS/400 9404 and TWINAX questions...

Wolfgang Eichberger &lt;cbmpet2001(a)yahoo.de&gt; wrote: Sorry, too many years have passed... I can't remember. <grin> Try here: http://www-1.ibm.com/servers/eserver/support/iseries/index.html Start with the 3197 terminal. It will either have 1 or 2 twinax ports. If two, just connect a twinax cable between port 1 on the terminal and port 0 on the AS/400. If one, you will need a "t-cable" to connect to it to provide the two ports. Twinax is somewhat like old 10base-2 (coax) Ethernet, where the terminals are "daisy chained" and the end of the cable is terminated. With 10base2 the terminator was a separate item, but with twinax it is built into the device or T-cable - examine it carefully, you will see a small plunger on port 2 which switches out the terminator when a cable is screwed in to extend the chain. You can use CAT 5 with special baluns and filters, but only for short runs. The data rate is only 1 MB/sec but it is susceptible to reflections if the wrong cable is used or it is not properly terminated, even in short runs. Properly run and terminated twinax will work over runs up to 1 mile long. The actual data stream is pure SDLC protocol in multi-point mode - each terminal polled in turn by the controller in the system unit. The OS license is tied to both the machine and the customer. I seem to recall it is a monthly charge, no pay means no valid license. There is no other OS than OS/400, IBM did publish full specs to allow anyone to write their own OS but no-one ever did. The system software comes on tape (QIC-120 or 9-track, depending on the drive in your machine). Some microcode and diagnostics come on 8 inch diskette. Note: Don't just power it off while running after it has IPLed. You'll be in for a very long (up to a full day in some cases) rebuild phase on next power up. That's why many AS/400 systems had battery backup like yours, so they could be shut down properly if there was a power failure. I think I remember the command... PWRDWNSYS *IMMEDIATE Good luck, the AS/400 and OS is different from just about any other machine/OS you may have seen. It's actually quite simple and logical to use, provided you are not familiar with operating other OSes. It is an object oriented system, and with no concept of disks or files. Everything is an object with attributes, and all objects are conceptually in main memory at all times (64 bit address space, so plenty of room). Each sector on the hard disks has its own 64-bit beginning address - each sector is formatted to 520 bytes instead of 512 to provide room for the address. The system maintains tables of addresses versus disk location, and it is these tables that take a long time to rebuild after a forced power off. You really should try to get the manuals, there is online help but the manuals will provide a lot of background information. -- Don Hills (dmhills at attglobaldotnet) Wellington, New Zealand It's ironic that people who are too smart to engage in politics are governed by people who are not as smart.