[net.unix] Need help getting v7m to run on 11/23

dan@rna.UUCP (Dan Ts'o) (06/19/84)

Hi,
	Re: your clock problems.

	UNIX can't use a KWV-11C. That is a programmable real-time clock and
unless you hack your UNIX, it expects a simple line clock.
	Most 11/23 systems have a LTC (line-time clock) hardwired into the
backplane from the power supply. The 60Hz signal is applied to the BEVENT
line of the Qbus.
	UNIX expects a hardware device register at 177546 to be able to switch
the 60Hz interrupts on and off. There a few Qbus modules which implement this
function, for example the BDV-11 bootstrap board implements the LTC switch by
clamping the BEVENT line on the bus. The KPV-11 also implements this clock
register.
	If you don't have any of these clock boards, you can still run UNIX by
commenting out the references to 177546, I believe in clock.c and main.c.
Most Qbus chassis provide a switch to turn on and off the 60Hz signal to the
BEVENT line. So 1) comment out the references to 177546 and recompile the system
then 2) turn off the LTC before booting, then 3) turn on the LTC after booting.
	You could, I suppose, cheat by putting a parallel interface (or maybe
even serial) at 177546 to avoid recompiling the system since all UNIX does is
to write a 115 (clock on) into 177546.
	To avoid the inconvenience of having to turn off and on the LTC during
booting you must add code into UNIX and the UNIX bootstrap to ignore the LTC
interrupts during a boot. Basically run the bootstrap at spl7() (I believe all
the old bootstraps only do polled I/O, not interrupt I/O). Then add code in
main.c to spl7() and include code in clock.c to ignore clock interrupts until
the kernel is initialized (e.g. iinit(), cinit(), etc. done).

	I hope this helps.

						Cheers,
						Dan Ts'o
						...cmcl2!rna!dan