RS6k 7012/320H woes

Paul Berger phb.hfx at
Tue Nov 6 19:24:13 CST 2018

On 2018-11-06 8:39 PM, Carlos E Murillo-Sanchez via cctalk wrote:
> Paul Berger via cctalk wrote:
>> 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.
> Carlos.
For loading the diagnostic from diskettes diskettes see the section 
"running diagnostic program from diskette" in the previously mentioned 
"Diagnostic Information for Microchannel Systems"  the key switch has to 
be in the service (wrench) position insert the appropriate boot diskette 
there are two  8MB of memory and >16MB of memory turn on power and after 
the self test it should start reading the diskette and when it finishes 
it will display C01 to prompt for the next diskette if that does not 
happen either the image is bad or there is a problem with the diskette 
drive.  There is a reasonable good chance that there is an issue with 
the diskette drive, especially if it was sitting on a carpeted floor.  
Typically the diskette drive was rarely used and the fans in the system 
will draw air in through the diskette drive carrying all kinds of 
contamination with it, you may want to open the drive up and clean it 
out and clean the heads.  It is very likely that the diskette drive in 
the machine has the power lines in the ribbon cable instead of a 
separate power connector making replacements hard to find.

As for the serial there is only one scenario that works fully pined 
cables with a null modem that matches the wiring of   the printer 
terminal interposer.

I don't think that an ethernet card is going to be a big help if you 
want to use the AIX that is on the disk as you have no way of 
configuring the ethernet network unless you can get a terminal working.  
Another roadblock may be the root password, it is possible to break in 
when you have physical access to the machine however you still need a 
terminal and you also need original install media at the same level of 
AIX or a mksysb backup tape from the same level of AIX to boot into 
maintenance mode.  The original install media for a machine of this 
vintage would have been a tape or lots and lots of diskettes.

Getting diagnostics to work would be a really good start.

The AIX on the SP2 would have been the same, in fact the hardware on the 
SP2 nodes was similar to the regular RS/6000 boxes except the console 
was through a special serial network in the frame and accessed through 
the control workstation.  Most regular users likely accessed the nodes 
through a LAN.


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