RAM testing & ROMs

[Ron Bean]

In Article <1990Dec12.065224.10906 at i88.isc.com>, botton at i88.isc.com
(Brian D. Botton) writes:
 
>......my machine started having memory problems in low memory, i.e., the area
>of memory that the diagnostic disk doesn't check because it that's where it
>get loaded.  The technical reference manual talks about a memory diagnostic
>ROM as well as a monitor ROM.  If anyone out there has either one of these,
>please let me know, I'd like to make a copy of them.
 
   My first reaction is that you should be able to test that memory without
changing the ROM. Since you know how the boot loader works, why not write a
floppy-based diagnostic program that starts by relocating itself into some
other area of memory?
 
>  I am looking for suggestions for addition to the ROM.  As it sits now, the
>ROM uses only ~4k out of a possible 32k.  What would you like to see?  Is it
>worth the trouble to put a monitor program in so you can hack at the lowest
>level?  How about being able to tell the system to boot from a different
>disk then drive 0?  I'm wide open for suggestions, and possibly some help.
 
   I'd like the ability to boot the regular diagnostics disk (or
equivalent) from a terminal on the serial port. Someday the CRT will go up
in smoke and there may or may not be spares available by then. Unix itself
shouldn't care, but can the diagnostics be redirected? I should memorize
the keystrokes to park the disk heads (I've never understood why it
couldn't park the heads just before it prints "Press RETURN to reboot").
 
   Someone mentioned the possibility of using a multisync monitor (are they
available in monochrome?). Does anyone know anything about the CRT
controller? Maybe it can be reprogrammed for a cheapo monitor? Lots of time
to work this out before the supply dries up, but let's not wait until it's
too late...
 
==================
zaphod at madnix.UUCP (Ron Bean)
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