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ZUAC??: NIE Exerciser Diagnostic. This is a tool which allows discovering nodes on the network. Does not seem to be very useful.
ZUAD??: Functional Diagnostic. This test needs a loopback connector on the AIU connector, and consists of 27 subtests.
Running the test, however, does not go well:
| Code Block |
|---|
BOOTING UP XXDP-SM SMALL MONITOR
XXDP-SM SMALL MONITOR - XXDP V2.4
REVISION: D0
BOOTED FROM DL0
28KW OF MEMORY
UNIBUS SYSTEM
RESTART ADDRESS: 152010
TYPE "H" FOR HELP
.R ZUAD??
ZUADB1.BIC
DRSSM-G2
CZUAD-B-1
DELUA - PDP11 FUNCTIONAL DIAGNOSTIC dtd 28-MAR-86
UNIT IS DELUA
RSTRT ADR 145702
DR>STA/FLAGS:HOE
CHANGE HW (L) ? Y
# UNITS (D) ? 1
UNIT 0
WHAT IS THE PCSR0 ADDRESS? (O) ? 174510
WHAT IS THE VECTOR ADDRESS? (O) ? 120
CHANGE SW (L) ? Y
RUN EXTERNAL LOOPBACK MODE TEST (REQ. H4080 OR EQUIV. LOOPBACK ? Y/N (L) N ? Y
TO AVOID MAN. INTERVENTION INSTALL H4080 OR EQUIV. LOOPBACK NOW? Y/N (L) N ? Y
ILL INTER 010
PC 035554 PS 000341 |
It seems to hit a trap 010 which is an “Illegal Instruction” trap. Looking at Joerg Hoppe’s diagnostics database fiches the test documentation states:
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The Unibone emulates a 11/20 CPU, which is one of the earliest CPUs. I checked. That same fiche, for ZUADB0 (we are using ZUADB1, so there will be differences to be aware of) shows this code at the address around 035554:
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This is an instruction from the “Extended Instruction Set”, and so it is logical that we die on it on the Unibone. Trick is going to be to extend the emulator to support the extended instruction set too.