Sage II - Page 2 of Schematic Diagrams; System Clock; Address Decoding

SAGE
II
SERVICE
MAI\ruAL
I
I.OJ
SUBSYSTEM
MODIFICATIONS
xv
SUBSYSTEI.{
}IODIFICATIONS
:
SAGE has
made
the
followlng
modificatl-ons
l-n-house.
Ttrese
changes are
fully
supported
by
SAGE.
I'TICROPOLIS
DISK
I'IODS
Install
a
Jumper
at
positlon
ll22
on rhe
disk
drlve
clrcuit
board.
I'IICROPOLIS
DISK
SETUP
For
left
hand
drlve lnstall
one
shortlng
block
at
positlon
Wl
of connector
J2.
For
rlght
hand
drlve lnstall
one
shorting
block at
posltlon
W2
of connector
J2.
There
shal1
be only
one
SIP termLnatlon
reslstor
pack
(locatlon
RNI)
per
computer
and
1t
shall
be
lnstalled
ln
the
righr
hand
drLve.
I.TITSUBISHI
DISK
I,TODS
}TITSUBISEI
DISK
SETUP
TANDON
DISK
}IODS
TANDON
DISK
SETUP
None.
The
seven resl-stor
pullup
straps
should
be
removed
on a
drlve which ls
closest
to
the
cpu in
a two
drlve
system
the
iiead
load
Jumper
should
be ln
the
'rl$fr
posl_tl_on.
The
drlve
should
be
selected for
the
approprlate
posltion.
A
Jumper
wire ls
connected
between
pin
2
of
J4
and TP13.
Resl-stor
(
R49) has
rhe
end
towards
the strapplng
block
moved to
the
adJacent
pad
(n50;.
The
strapplng
bLock
determines
the
drlve
device
number.
Normally the
left hand
drlve
ls
devlce
4,
the rlght hand
drive
ls
device
5.
For
the
left
hand
drlve
count from
the
edge
closest
to the
edge
of
the
circuit
board.
Remove
all
but the
first
two
straps.
For
the rlght
hand
drlve remove
all
but
the
flrst
and
third
straps.
ltrere
shaLl
be onl-y one
dtp
termlnatlng
reslstor
pack
(Zf;
per
computer
and
lt
shall
lnstalled
ln the
rlght hand
drive.
50