Sage II - Page 89

sAcE
II SERVICE
MANUAT
[1.0J
HARDI^IARE
CHANGES
ON
SAGE
II
CHANGES
FROM
CB0000
TO
CB000l
(conr)
The delay
1lne
layout
was
changed to
make
types
of delay
lines.
(See
the
Delay 1lne
The
parlty
clrcuit
was
changed:
U50-l
to
U32-12 to
U41-1
(BRw+)
U50-2 to
pin
14
of
Lower
Parity
U50-3
to
U64-4
tI32-13
to
pin
14
of
Upper Parity
U32-11 to
U31-4
Pin
2
of
Lower
parlty
RAM ro
U64-6
Pin
2
of
Upper
Parlry
RAM ro
U3l-6
U39-14 to
U37-9
U37-8
to
U5l-10
mods easler
for
the
dlfferent
notes in
thls sectlon.)
RAI'{
RAM
xrx.04
CHANGES FROIi
CBOOOI
TO
C80002 :
The
CB0001 was not
modifted
to
conform electrlcally with
the C80002
except
where
speciftcally
detalled below.
One side
of
ground
on the floppy
ribbon
connector
(pln
34
of
J4)
was
cut
to remove
a
ground
loop.
Factory
mod
was
done
to
some
CB000ru.
The
Reset
swltch
layout
had
a
ground
loop whlch was removed.
CB000l
had
these
chips
silkscreened
wrong:
U35 was
shown as
LS245 should
be
LS240
U59,61 was
shown
as
75189
should be
1489
U60 r^ras
shown
as
75188 should be
1488
The CB0001
had
one factory
mod
to
connect the termlnal
port
CTS
(J10-5)
to
U5l-4.
The
CB0002
changed
the termlnal
port
CTS layout. +5V
hTas removed
from
pln
4 of termlnal
port
U51.
Pln 4
was
connected to strap
S05
lnput.
*l2V
was connected
to
A
of 506.
Pln
5
(CTS)
was
connected to
B of
506.
thls
connects
all three
points
of
the strap
so
that
CTS
normally
hlgh.
To drlve
CTS, the
connectlon
to
B
(+12V)
must be cut
flrst.
(See
the
506
strap
mod
for
the
C80002 as the
change
for this
was not
quite
rlght.)
The
C80002
changed the
termlnal
port
DSR
layout.
Pl-n
6
of the termlnal
port
was
connected
to +L2V.
(User
DSR) Pln
20
of the termlnal
port
was
connected
to
u51
ptn
13.
(SAGE
DSR
)
This wtll allow
a
user
cable ro be
made whlch
holds
DSR high
by wlrlng
pln
6
to
20
on
the termlnal
connector.
Thts
was
done as
a
convenlence
to the
user so
that tt ls
not
necessary
to
change
an lnternal
strap.
80