RS6k 7012/320H woes

Carlos E Murillo-Sanchez ce.murillosanchez at
Tue Nov 6 18:39:51 CST 2018

Paul Berger via cctalk wrote:
> Those code you highlighted are only a problem if it halts on that code 
> if it continues on then its ok, in fact it is finding something to 
> boot off of 299 means that it has loaded the bootable code from 
> somewhere, in your case likely the disk and has transferred control to 
> it.  Do you know if this machine ever had a graphics card of some kind 
> installed?  if so then it would likely have been defined as the 
> console, if not then it may be a matter of finding out which serial 
> ports where set up as TTYs.  If the disk does in fact have AIX 
> installed on it you will only see activity on ports that have a getty 
> running on them.  Do you have anything like diagnostic diskette or 
> original install  media you could boot from?  Either one of those 
> would check all the serial ports for a terminal.  The RS/6000 is very 
> picky about the serial connections and does want to see certain 
> signals present before it will talk to a serial port.   Search for the 
> manual "Adapters Devices and Cabling Information for Microchannel 
> Systems" near the back there is a section about cabling  pay attention 
> to the device called printer/terminal interposer there is a wiring 
> diagram, it is effectively a null modem.    Another potentially useful 
> manual is "Diagnostic Information for Microchannel Systems"  There are 
> equivalent manuals for the early PCI systems as well substitute 
> "Multibus" for Microchannel"
Since it does not stop after the "290 IOCC POST error (irrecoverable)." 
code, then perhaps there's hope.  I made diagnostic diskettes from 
images that I found on the net, and the system reads the diskette on 
power up, but after a while it goes back to reading the HD instead.  
When it reads the diskette it does not sound like it fails to seek or 
read, but it is possible that the diskette was not written correctly.  
As for the null modem cable, I actually tried several schemes in an 
RS-232 break-out box, but none worked.  Just silence, and most 
important, no assertion of the DTR or RTS lines on the part of the 320H, 
even when CTS, DCD and DSR are being asserted from my terminal.

I am pretty sure that this machine was always headless;  it was used for 
accounting and inventory in a small business and all it had was 
terminals, a printer, and the tape drive.

If it seems like it can be revived, perhaps I will invest in a LAN card 
for it.

My only experience with AIX was as a user in a big SP system at Cornell 
in the 90's; I loved  it, but it was only from a user's perspective, not 
an admin.


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