Classic Mode

Star Tech Journal

Issue: 1982-November - Vol 4 Issue 9

10
-sTAR*TECH JOURNAL/NOVEMBER 1982
A Regular Monthly Feature Technically Outlining a Newly Released Game
NINTENDO'S "DONKEY KONG JUNIOR"
By Joe Connor, Active Amusement Co., Philadelphia, PA
After the great success of Nintendo's first big hit game,
"Donkey Kong" , it's only natural that a sequel to the
original should be released. At one time, it could be said
that remakes always seemed to be disappointing, falling
well short of the players', as well as the operators',
expectations. The recent success of "Ms. Pac-Man",
however, indicates that remakes can be very profitable if
they manage to stay close enough to the original game, yet
(and this is the hard part) provide new and varied
challenges for renewed player interest. Initial response
would seem to indicate that "Donkey Kong Junior" is
generating this kind of interest and is going to be a
successful remake. There have been slight variations to
the original game theme (" Donkey Kong" has been
captured and now Mario is the "heavy") but the same
basic elements of game play still exist - the player starts
at the bottom of the screen and must run, jump, and climb
his way to the top, avoiding a brigade of snapping jaws,
ape-eating birds, and energy pods launched at him. Like
"Donkey Kong", there are four distinctly different screens,
each providing a new challenge with varied sound effects
and outstanding visual imagery.
The electronics package is almost identical to that in
"Donkey Kong" . There are minor changes to the board
set, but the monitor, wire harness, and power supply are
identical in both games. The overall game design is all
Japanese right down to the high quality components,
switching power supply, and non-existent self test.
SYSTEM POWER
The system power (see diagram) is provided by a single
isolation transformer and a switching power supply
mounted on an assembly in the bottom of the cabinet. The
switching power supply negates the need for any additional
transformers since the input for it is I OOvac.
Traneformer - There are two secondary windings
coming off the isolation transformer. One winding supplies
SYSTEM POWER
Power
Supply
(Switching)
10Ovac
Line
Voltage
On/Off
Switch
Isolation
Trans.
JOOvac (1.2 amps) for the monitor and fluorescent tube.
The other winding (JOOvac, 1.6 amps) supplies the input
to the switching power supply. Since most domestic line
voltages are usually between 115 and 120vac, this
transformer is not only isolating the incoming line voltage
but also stepping it down slightly. The transformer is
protected by a 5-amp fuse screwed in next to the line cord.
Switching Power Supply - The power supply, like
those used in some other games (Centuri "Phoenix"), is a
switching power supply. It is capable of delivering + 5 and
-5 volts at 5 amps as well as + 12 and + 24 volts ( using 3-
pin package regulators). By using numerous low power
transformers and an array of inductors, rectifiers, transis-
tors and capacitors, this power supply can operate
extremely efficiently (no heat dissipation), wasting much
Jess power than the standard power supply. The switching
power supply used in "Donkey Kong Junior" is the same
one used in "Donkey Kong" (PP-7B). There is a single 4-
amp fuse located in the power supply, protecting the
lOOvac input voltage. Voltage adjustment pots are also
located inside the power supply, but usually no adjustments
are necessary.
Principle advantages of this power supply are its
reliability (no heat buildup), inexpensive (hard to believe,
but using all these parts is cheaper than purchasing a high-
power multi-tap transformer), and it's lightweight.
Principle disadvantages all involve servicing. Just
opening up this power supply is an accomplishment in
itself. A trained gorilla must tighten the machine screws
holding the power supply together! The fuse usually
doesn't blow, but when it does, it usually means there are
other problems with the supply. After opening the power
supply, you are greeted by two printed circuit boards
interconnected by numerous cables. If you're lucky enough
to isolate the failing parts (NEC type), you probably
won't stock them or be able to find a cross reference on
them. Using the " one handed" method of troubleshooting
10Ovac
A.C.
Outlets
(2)
Clrc ■H
11111
LlcallH
Line-in
(12Ovac)
SA
Screwed in next to
line cord bracket on
bottom right side of game
Power Supply
Input (1 OOvac)
4A
Inside power supply cage
Monitor
Input (1 OOvac)
4A
Monitor
Monitor
B+ voltage
.3A
Monitor
Video
Board
+Svdc------4
-Svdc -----➔
+12vdc---,
+24vdc
10Ovac _ _ _ _ __,
1 OOvac - - - - - - ,
CPU
Board
1
Monitor
1
Fluorescent
Tube
N1t11:
1. On/Off switch located below back door, right side.
2. There are NO interlock switches.
3. A terminal block for varied line voltage is mounted next to
transformer.
4. AC outlets may appear as utility outlets, but are provided for
fluorescent tube and monitor.
*Isolation transformer provides 1 OOvac output for 12Ovac input
11
STAR*TECH JOURNAL/NOVEMBER 1982
is probably the most efficient andsqfest. With one hand in your pocket, use your
other hand to call up Nintendo and receive a return authorization number. After
receiving a return number, send the supply to Nintendo and let them work on it.
Fortunately, these power supplies are very reliable and usually no problems are
ever encountered with them, but when they are ... !
VOLTAGE
+ Svdc
Svdc
+ 12vdc
+24vdc
DESTINATION AND FUNCTION
Video and CPU Boards (VCC)
Supply voltage/all ICs
Video Board (VEE)
HD10124,HD10125,MB7074RAM,HD10116,HD10105,
MB10136. (Power inputs pin 8 on all ICs except MB7074
RAM (pin 12).
CPU Board
DAC 08 (pin 3)
MB3614 (pin 11)
CPU Board
Not used ( optional on-board audio amp not installed in
"Donkey Kong Junior").
CPU Board
Outputs to coin counter.
volts is primarily used to power a group of ECL ICs on the video
The -5
board.
HD 10105 -
HD 10116 -
HD 10124 -
HD10125 -
HD 10136 -
MB 7074 -
Triple 2-3-2 input Or/Nor gates.
Triple line receiver.
Quadruple TTL to ECL translator.
Quadruple ECL to TTL translator.
Universal hexidecimal counter.
ECL RAM (with heat sink).
ECL stands for emitter coupled logic. This type of logic works on current
instead of voltage; a "l" is so many microamperes and a "0" is so many less
microamperes. This is the fastest memory circuitry available and usually
requires triple layer PC boards (not in this case). These ICs are "power hogs"
and require hefty power supplies (-5 volt supply in "Donkey Kong Junior" can
deliver up to 5 amps).
PIN CONFIBUIIATION
I/OR
I/OW
MEMFi
MEMW
MARK
READY
HLDA
ADDSTB
AEN
HAQ
cs
CLK
RESET
DACK2
DACl<.3
DRO3
DRO2
DRO1
DROo
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
CPU Board (DJRJ-01) - The CPU board, as the name implies, is the
home of the central processing unit. This processor circuit consists primarily of
a Z80A microprocessor, which can access 24K bytes of program memory. There
is also an 8275-5 DMA controller for rapid access to the large memory. In
addition to the game microprocessor, there is also a separate sound micropro-
cessor (MBL 8035) which controls the sound circuitry. This processor, in
conjunction with a 4K program ROM, is responsible for all sound generation
except for the climbing, jump and thump sounds. These individual sounds are
controlled by circuitry external to the sound processor. All sounds are summed
together at the base of Q 1 and sent out to the audio amplifier in the monitor. The
CPU board also contains all input circuitry ( switch inputs) and output circuitry
(coin counter, sync and color information).
HARDWARE
Game microprocessor (7C) - Z80A
Program PROMs (SB, C, D) - 2764
Sound microprocessor(7H)-MBL 8035
Sound program PROM (3H) - 2732
DMA controller (7E) - 8257-5
Output color PROMs (2E, 2F) - 24S10
DMA Controller(8257-5)-The above hardware listing identifies aDMA
controller in position 7E. This IC (8257-5) is designed to simplify high speed
transfers between peripheral devices and memories. Essentially, it allows the
processor ( Z80A) to carry out other tasks while the DMA controller generates a
sequential memory address. In "Donkey Kong Jr.", these transfers appear to be
from one memory area ( display ROM) to another memory area ( display RAM).
This IC is one way that Nintendo manages to display numerous screens, each
one with very detailed images,
29
28
14
27
15
16
17
18
19
26
25
24
23
22
21
20
A7
A6
A5
A4
TC
A3
A2
A1
Ao
Vee
Do
D1
D2
D3
~
DACKo
DACK1
D5
D6
D7
PIN NAIES
D7-Do
A7-AQ
I/OR
I/OW
MEMR
Oita Bus
MEMW
Memory Write
CLK
RESET
READY
HAO
HLDA
AEN
ADSTB
TC
Clock Input
Address Bus
1/0 Road
1/0Writt
Memory Flt.S
Reset Input
Ready
Hold Roquost ho 8080AI
Hold Acknowtadgt I from 8080AI
Addrtu Enable
A.ddrns Strobt
DRO,-DR0o
DACK:tDA~KQ
T 1rmin1I Count
Modulo 128Mork
DMA Roquost Input
OMA Acknowtadgt Out
cs
Chip Select
Vee
+5Volts
GND
Ground
MARK
BOARD SET
Unlike "Donkey Kong", which used 2 and 4 board logic sets, "Donkey Kong
Junior" uses only 2 board sets. There are slight variations in design, but
essentially the boards are the same (a "Donkey Kong Junior" board set and
"Donkey Kong" board set are interchangeable in the games). The boards are
mounted back to back on a metal bracket and interconnected by two SO-pin
ribbon cables. The set consists of a CPU board on the top end and a video board
on the bottom.
µPD
8257/
8257-5
40
39
38
37
36
35
34
33
32
31
30
Even though this board closely resembles a "Donkey Kong" CPU, it is not
quite the same. This board has been redesigned to accommodate 28-pin, 64K
(2764) program PRO Ms. The program PRO Ms used on "Donkey Kong" were
24-pin, 32K (2532) PROMs. Obviously, interchanging 24-pin PROMs and
28-pin PROMs is impossible and prevents PROM only conversions from
"Donkey Kong" to "Donkey Kong Junior''. In addition, there were 2 2716
sound PROMs on "Donkey Kong". On "Donkey Kong Junior", however,
there is only a single 27 32 PROM. Even the two color PRO Ms (2E, 2F) are
different in each game.
TEST POINTS
TPl - Ground
TP2 - Reset
TP3-V. BLK
TP4- V. Sync4'
TPS - H. Sync4'
•No post mounted on board.
Video Board (DJRl-01 or modified TKG4-14) - The bottom board
contains all circuitry having to do with video generation, including the master
oscillator and sync circuits. There are separate circuits dedicated to the display
of the background objects as well as all the moving objects. The principle
elements include the image PROMs, color RAMs, object RAMs, and horizontal
data RAM.
HARDWARE
Image PROMs (moving images) (7C, D, E, F) - 2716
Background PROMs (3P, 3N) - 2732
Object RAMs (6P, 6R) - 2148
Horizontal Pos. RAM (7M) - 93419
Background Color RAM (2P, 2R) - 2114
Color PROM (2N) - 24S10
Moving Color RAMs (attack) (2E, 2H) - MB7074

Download Page 10: PDF File | Image

Download Page 11 PDF File | Image

Future scanning projects are planned by the International Arcade Museum Library (IAML).

Pro Tip: You can flip pages on the issue easily by using the left and right arrow keys on your keyboard.