Apple Orchard 1980 Fall v1n2 reduced

PAGE 34
THE APPLE ORCHARD
FALL 1980
presents a problem, point the
antenna in the direction of the
station. Improvements of an order
of magnitude are common. Most
" log periodic" antennas have a
very good "front to back ratio" and
simply pointing the antenna away
from the source of interference is
very effective.
A very useful, but inconvenient,
step in the analysis of an interference
problem, is to carry a
portable TV set right up to the TV
receiving antenna and connect it
directly to the antenna, via a foot or
so of twin-lead. With all other leads
removed, check for interference. If
interfence persists, then the
radiation from the computer will
have to be reduced . If the interference
has gone away, then the
lead-in system will have to be fixed
somehow.
If the interference is determined
to be from the computer, then the
following procedure should help in
cutting it down. NOTE: This
procedure may void your warranty.
Required parts (Apple Kit Part
#652-0152)
1- Two 0.1 uf capacitors-
Apple part #132-8101
2- Two solder lugs-
Apple part #517-0009
3- Six ferrite beads (Toroids)-
Apple part #159-0001
MOTHERBOARD REMOVAL
1- Power off.
2- Remove Apple lid and any peripheral
card plugged in.
3- Turn Apple upside down and
rest keyboard on protective
foam pad.
4- Remove six flat-head screws
from three outside edges of flat
portion of Apple base. (See
number 6 on figures page).
5- Remove four round-head
screws and lock washers from
front of base; (number 7).
6- Grasping both base and housing,
turn Apple right side up.
7- Gently lift front of housing
slightly off base and unplug keyboard
connector from location
A7 at front of motherboard;
(number 1 ).
8- Lift housing off base and set
aside.
9- Pinch sides of power supply
plug at location K1. Release and
lift it out; (number 2).
10-Unplug speaker connector at
location B8 on motherboard;
(number 3).
11-Remove 5/16 inch nut and lockwasher
in middle of motherboard
(do not forget to reinstall
it later!); (number 4).
12-Push in on flanges with
screwdriver, or needle-nose
pliers, to release four stand-offs
at corners of board and two
stand-offs between 1/0 connectors
4 and 5; (numper 5). Lift
board up and out. Lay gently to
the side.
CAPACITOR INSTALLATION
1- Feed one end of each capacitor
through small hole · (from
uplifted side) of each lug
respectively.
2- Solder lead to lug and cut off
excess.
3- Remove back left and right
stand-offs by removing screw
fi-om underside.
4- Scrape paint off top side of
base plate around mounting
holes of above mentioned
stand-offs.
5- Place lugs, uplifted side
pointing up, one each between
base plate and above meri~
tioned stand-offs. reinstall
standoffs.
6- Reinstall motherboard.
7- Scrape solder mask off motherboard
next to back left and
right mounting holes. .
8- Solder other leads of capacitors
to just scraped areas of motherboard
and cut off excess leads.
9- Reinstall motherboard to base.
10- Add a ferrite bead to the
keyboard cable before
reinstalling it into location A7
on motherboard; (numper 1).
11- Reassemble and test Apple.
FERRITE BEAD INSTALLATION
1- Power off.
2- Take one end of monitor cable
and thread as many turns as
possible through it, then
reconnect it.
3- Repeat procedure at other end
of cable.
4- Add a ferrite bead to any
peripheral cable going out of
the Apple. One or two turns
should be adequate.
(continuccl on page 35)
***SYNTAX ERR
Corrections to "Applesoft Internal
Entry Points", Apple
Orchard Vol. I, No. 1
In HIRES GRAPHICS SUB­
ROUTINES, entry ciddresses
should be corrected as shown
below.
ROUTINE
WAS SHQULD BE
HGR2 F3D4 F3D8
HGR F3DE F3E2
HCLR F3EE F3F2
BKGND F3F2 F3F6
HPOSN F40D F411
HPLOT F453 F457
HLIN F530 F5~A
HPLOT: The entry conditions
are:
. Horizontal = Y,X
Vertical= A
Zero Page locations:
ROT $F9
SCALE $E7
Omitted under STRING
UTILITIES:
FREFAC E600
Frees temporary
pointed to by FAC.
FLASH CARDS -Page 90
(58880)
descriptor
Line 8020 RETURN was omitted.