Sage II - Power-Up Routine; Initialization Overview; PROM Versions and ROM Locations; Initialization Tests Sequence

sAcE
Ir SERVICE
MANUAL
[1.0]
POWER-UP
ROUTINE
VI I
POTER-UP
ROUTINE
:
The
power-up
routlne
ls
a
diagnostlc aid
wlthin
itself.
Thts
sectlon
explains
how
lt works
and
how
to use it
for troubleshootlng.
If the
early
porElons
of the
boot fail,
Do
error
messages are
glven
but
the
processor
LED
will-
turn
RED.
An
oscilloscope is
necessary
to lsolate
the
problem.
verstons
of Lhe
PROMS before
3-Jan-83
do
not
have
all of
features
descrtbed
here.
The
dlfferences
are explalned
updaEes found
in
the front
of
your
SAGE
Users' Manual.
The
power-up
routine
resides in
an
8K byte boot
ROM.
slmplex non-interrupt
drlvers for
self-test
of memory,
devlces.
Normally,
the
PRoI"lS reside in
memory at
address
reset
they
are
switched to
reside
at
000000.
the
diagnostlc
ln the
release
It
contalns
processor
and
F80000 but
on
On
power-up
or when
the
processor
is
RESET, the
processor
starts
executlng
the boot
program
at
memory locatlon
0. The
processor
reads
Ehe lnttial
stack
polnter
and lnitlal
start vector from
ROM locatlons
0
and
4
respectlvely,
The
start
vector
polnts
to
the address
of
Ehe
tnittallzation
code.
After
the initial
Eests, the executlon
of
an
address
over F80000
causes the hardware
to
swltch the
ROMs back
to thelr
hlgh
memory location.
Program execution
continues
out
of
the
new
ROM
location.
DescriptLons
of
the lnitial-ization
tests fo1low.
Note that
the
entire
initlalizatlon
test
sequence
can be
contlnuosly repeated
by
setting
the
swltches
as described
at the
end
of
this
sectlon.