Sounds like an interrupt problem.
XXDP don't use the interrupt system, so that will work.
Check bus grants.


Will Kranz wrote:
> While I am slowly getting somewhere.
> Dad had 3 full systems which haven't been booted in over 5 years.
> Looking closely at some of the terminals I find the note that it
> was know to be good in Nov 1992. All three were working with RL02
> boot disks at one point in their lives. All three seem to have at
> least partially functional CPUs.
> One system boots and runs RT11 from both RX02 and RL02.
> Two others, an 11/23 and 11/73, will boot XXDP from my TU58
> emulator which is promising. However they will not boot RT11 V4.0
> which I've previously used as my baseline. Its odd, very early
> on in the boot process (possibly after loading the boot block, but
> I'll verify this) for RT11 the 'Run' light on the front pannel goes out.
> However it does NOT fall into ODT, ie I don't get an @ prompt and
> address on the console. It does not respond to ^C etc, just hung.
> I can to a restart and repeat this, or boot into XXDP from the other
> tape image. This is new behavior to me, and I'm open to suggestions.
> Meanwhile I will reseat some boards, and do some poking around
> with XXDP and ODT to verify things.
> Will

Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol

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