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With System 80 starting with Mars God of War, Gottlieb introduced their
sound/speech board. This new board supported sounds and also made
the game "talk" (speech). Prior to Mars God of War, Gottlieb
used a simple sounds only board (as used on Spiderman and prior games).
This document applies to the sound and speech board only used from Mars God of War to Qberts Quest. This board was Gottlieb’s first attempt at speech and by today’s standards the speech is robotic and crude.
Sounds are generated on the sound/speech board ONLY. Data from the CPU is only in enable form. An example of this would be you imitating a CPU as a guy holding a CD player remote and the sound board as a 16 track CD. The CPU can change the tracks, but the sound board has all the music. That is why sound boards have game specific sound ROMs.
- Mars God of War #666, 4/81
- Volcano #667, 7/81
- Black Hole #668, 10/81
- Haunted House #669, 2/82*
- Devil's Dare #670, 8/82
- Caveman #810PV, 9/82
- Rocky #672, 9/82
- Spirit #673, 11/82
- Punk #674, 12/82
- Striker #675, 1/83
- Krull, #676, 2/83
- Q*bert's Quest #677, 3/83
These are the System80 games which use the Sound/Speech board covered in this document:
Starting with Super Orbit (5/83, the game right after Q*bert's Quest), Gottlieb went to a policy of "cheap is better", using particle board cabinets, small crappy coin doors, and a thinner head with no extra room inside. Also, the speech chip was already obsolete, so Gottleb just went with background music and sound effects. The weirdest thing they did with speech was on Bad Girls (10/88), where they implemented a seperate board that only said one word, "BAD", over and over (the only variation was to change the frequency so the voice went higher or lower). After playing about two games, the sound of "BAD" over and over got really annoying.
Important Note: some European export versions of Volcano, Black Hole (with 668A/S roms), Devil's Dare and Eclipse games were also fitted with the earlier sound (only) system80 board. Apparently just these games, as exported to Europe, where sometimes *not* fitted with the sound/speech board. This was a cost saving method Gottlieb used to lower the retail cost of exported games. But most examples of these games *do* have the speech/sound board.
Some Gottlieb video games also used the sound/speech board. The best known example was Q*bert. These video game sound/speech boards are fully interchangeable, but of course need the correct ROMs fitted for the game they are going in.
For the games following Q*Bert's Quest, the sound board becomes more complicated. For example, Super Orbit and Royal Flush Deluxe use the Sound/speech board but only the sound channel is used. Hence all the components related to speech are not installed (to cut costs). Also Amazon Hunt went out in two versions: one version with a modified sound/speech board (like Royal Flush Deluxe and Super Orbit), another with an earlier sound only board modified with a piggyback board in place of the 6530 RIOT and ROM chips. This piggyback board had a 6530 RIOT chip plus a 24 pin socket with a 2716 EPROM (instead of the outdated 7643 PROMs used on the older sound board). Games from the Mylstar era (Ready Aim Fire, Touchdown, Jacks to Open, Alien Star, The Games, etc.) also all used the older sound board with the piggyback board. Rack'em up and Premier-era games like Eldorado, Ice fever and games with alphanumeric displays up to and including Tag Team again have this same sound board/piggyback board combo as well. With the introduction of Rock, a new sound/speech board appeared (also used on Goldwings, Hollywood Heat, etc.).
First Step: Testing the Sound/Speech board & Speakers.
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Before doing anything, some simple tests can determine if the sound/speech
board itself is at fault, or the communications lines to the sound/speech
board.
- Pin 1 = +12 volts DC.
- Pin 3 = -12 volts DC.
- Pin 5 = +5 volts DC.
- Pin 6 = Ground.
- Pin 10 = +30 volts DC.
- Turn the game off.
- Set ALL the DIP switch on the sound/speech board to OFF.
- Turn the game on.
- Press the black sound/speech board test button - a tone should sound. At this point the board is testing its internal RAM and ROM chips.
- If the sound/speech board's RAM fails, "RAM TEST FAILS" will be heard.
- If either sound/speech board's EPROMs fails, "EPROM x FAILS" will be heard (where "x" is either "one" or "two").
- If these two test pass, the board will say "OFF", signifying that all the DIP switches are turned off.
- Now turn all the DIP switches ON. As the last DIP switch is turned on, the board should say "ON", and a tone sound.
- Turn all the DIP switches OFF, and the tone will stop.
- Press the black sound/speech board test button, and the board will say "COMPLETE".
Check the Sound/Speech Board Voltages.
The first thing to check is the voltages at the sound/speech board. The
sound board needs these voltages at the sole sound board connector A6P1:
The +5 volts is generated by the power supply board A2. So if this is not working, the sound board will not work! All other voltages supplied to the sound/speech board come from the A7 sound/speech board power supply (a smallish board with a large metal heat sink). This A7 power supply gets unregulated 24 volts DC solenoid power (from the large bottom panel transformer, through a bridge rectifier and no capacitor), and 12 volts AC (from the small bottom panel transformer). This A7 power supply then outputs +12vdc, -12vdc and +30vdc (all regulated) to the sound/speech board. If any of these voltages are missing, check the A7 sound/speech power supply.
Loud pulsating Ground Hum when Game Idol.
Always make sure the voltages are good. For example, on a Haunted House
the music was very poor, and there was a loud ground hum when the
game was in attract mode. Swapped sound boards but nothing changed.
Turned out to be missing -12 volts DC from the AUX power supply.
The fix was an open R2 100 Ohm (1/2 watt) resistor. Also diode CR2 1N4742A was shorted,
and C2 Cap 47Uf (25 volts) was bad.
The Speakers
After all the voltages are measured at the sound/speech board itself
and are correct, if there is NO SOUND, the next thing to check are the speakers!
Obviously if the sound board is making some sound you can skip this part.
Most system80 games have TWO four ohm speakers. If one of the two serially connected speakers are damaged, no sound will be produced! Also note that one connection of the speaker goes to ground, and the other connection goes to a 100 ohm volume pot. This in turns goes to the sound/speech board at connector A6P1 pin 7. If bad speaker(s) are suspected, a logic probe can be put on A6P1 pin 7 to see if any signals are being output.
The speakers can also be tested using a 1.5 volt "AA" battery. Connect the battery to each speaker lugs, and the speaker cone should push out or pull in. Only do this for a second so not to damage the speaker. If nothing happens with the battery, the speaker is dead. Also make sure the volume adjustment pot is hooked up and moving freely. A dirty pot will make sounds scratchy, but usually these don't go bad to the point of complete failure.
A set of headphones can also be used on the sound board. Hook an alligator lead to the part of the headphone plug closest to the plastic plug handle, and connect the other end of the alligator wire to ground. Now use another alligator lead and connect it from one of the other two sections of the headphone plug, to the lead of R15 (or R16) furthest away from the edge of the sound/speech board. Sounds from the sound/speech board should be heard in the headphones. If sounds can be heard in the headphones, but not at the speakers, then the sound/speech board's audio amplifier may have failed (or +30V at the sound board is low/missing).
Sound/Speech Built-in Test.
After checking the voltages and verifying the speakers work,
next try the sound/speech board's
internal tests. Depending on the sound/speech board's ROM software
and the actual game, the internal test acts differently. For
example, Haunted House uses the Sound/speech board, but has
no speech (unlike say Black Hole which does talk).
The following assumes you have a U14 speech chip installed (most games except Haunted House). If you don't have a U14 chip, skip down to the Checks part of this document for the non-speech version of this test, or check the game manual.
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The most common problem with the sound/speech board
is missing sounds, wrong sounds, or a board that won't "talk".
If the board is completely dead, it should be troubleshot like any
other MPU board (check voltages, check 6502 CPU chip's Reset line
to make sure it goes high, check clock signal, check all address/data lines).
A "DOA" sound/speech board won't be covered here in
much detail because it's not usually the problem.
Again the most common problem are missing sounds,
wrong sounds, or a board that won't "talk" (assuming
it's a game that does have speech).
Missing or wrong sounds usually relate to a problem with the communications between the CPU board and the sound/speech board. There are a number of "signals" that come from the CPU board that are munipulated by the driver board, and then sent to the sound/speech board. If any link in this chain is broken, problems will occur.
The Sound/Speech Input Lines S1,S2,S4,S8.
Before proceeding further, understand the sound/speech board has but SIX
sound "lines". These are identified as Sound1, Sound2,
Sound4, Sound8, Sound16 and Sound32 (aka S1,S2,S4,S8,S16,S32). Though all System80
games have more than six distinct sounds, it is these six
sound lines, used in combination, that determine which
sound is desired by the game. For example, if the game
wants to play the coin tune (the sound made when a coin is
dropped through the coin door and a credit is added),
Sound1 and Sound4 are similtaneously pulled low, and
the sound board responds with the desired sound.
Sound implementation S1,S2,S4,S8 on all system 80 games is the same. It starts out at the CPU board U6 RIOT chip as four line data signals P0,P1,P2,P3. They travel through chip Z27 (a 7404 inverter). At this point the sound and coil data look identical, except for a sound enable line PA4 that goes through it's own gate on chip Z27. Then these signals go to CPU chip Z31 (7408) where they are AND'ed together. If the PA4 sound enable line is high AND a P0,P1,P2,P3 line is high, the Z31 outputs a high signal which goes to the driver board Z13 chip (7404 inverter), and then to the sound board, which triggers that sound. The key is the PA4 sound enable line. If this is not high, yet a P0-P3 line is high, the signal is not output by Z31, and hence no sound (instead a coil is fired). That's how the P0-P3 lines can be used for coil signals and sound signals.
S1-S8 Sound/speech lines at the CPU board.
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I would rule out the CPU U6 (RIOT 6532) and Z27 (7404)
chips if all your coils are firing OK, but your sound is not. A problem
could still be in that one gate of Z27 though, but this is rare. This would often cause
NO sound since this is the sound enable line. Remember chip Z27 is also using the same P0-P3
line for coils, if the coils are working, chips Z27 and U6 probably are too.
But this still leaves CPU board chip Z31 as a problem (remember this chips ANDs
the P0-P3 and P4 enable lines together, which gives a sound signal to the
driver board and to the sound board).
Next down the line is the driver board's Z13 (7404), an inverter chip that takes the signal and outputs the exact opposite. So a "high" input sound signal will produce a "low" output signal through this driver board Z13 chip. Sound S1,S2,S4,S8 all go through the driver board Z13 chip, and then go to the sound board as low signal triggers.
S1-S8 Sound/speech lines at the driver board.
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The S1,S2,S4,S8 sounds are now seen by the sound board.
These four lines can be interpretted as sixteen different sounds/speech,
depending on which ones are on or off at the same time.
- Connectors. Check the CPU to driver and the driver to sound board. These are often corroded, broken, or just not making contact. Reseat them a few times to see if they come back. If they do this is an indication that the connectors are bad! Fix any pins that look troubled.
- Bad speaker terminals and dirty volume pot. Check both and move the pot back and forth.
- Z13 buffer on driver board. This chip is often the cause of no sound of some missing sounds. Usually one gate (inverter) is not working and you lose one of you S1,S2,S4,S8 data lines. These are cheap and can be replaced pretty easy with a socket and a new chip. Got another system 80 game? Pop in that driver board and check to see if your sounds come back. ALL system 80 games used the same driver board, so any will mix and match.
- Bad 6532 RIOT on the sound board and U6 at the CPU. Try swapping these with others if socketed. U4, U5, U6 and the sound 6532 chips are all the same. The sound board RIOT is always socketed. The CPU ones usually are not. I would suspect the sound board RIOT first if your coils and lamps are working OK. These all come out of U6 on the CPU.
- Z31 at the CPU. This is rarely bad, but might be the case.
- Z27 at the CPU. Four out of the five gates control coils and sounds, so your coils should be OK too. There is one gate that is sound only, so that one might not work. You won't get sounds if that one last gate is dead since that is the sound enable line.
- Dead sound board. Did you do the suggested sound board checks (if any) listed in the manual? This will help determine if the data chain is bad or if the sound board itself is toast.
- With ALL the DIP switch on the sound/speech board to OFF, and the game on, press the black sound/speech board test button. A single tone should sound.
- The board should say "OFF", signifying that all the DIP switches are turned off.
- Now turn all the DIP switches ON.
- Press the sound/speech board test button again, and a tone should sound.
- One at a time, momentarily connect the following connector pins of A6J1
on the sound board
to ground (pin 1 is the top most pin closest to the heat sink):
- Pin 8 - sound board should say "one" to signify Sound 1.
- Pin 9 - sound board should say "two" to signify Sound 2.
- Pin 11 - sound board should say "four" to signify Sound 4.
- Pin 12 - sound board should say "eight" to signify Sound 8.
- Pin 2 - sound board should say "sixteen" to signify Sound 16.
- Pin 4 - sound board should say "thirtytwo" to signify Sound 32.
- Press the black sound/speech board test button, and the board will say "COMPLETE".
The Dreaded S16 Sound Line.
There is another sound line called S16. Many sound board problems
relate to this line. For example, on Haunted House if S16 is missing,
the pop bumpers when hit will play the game's start-up tune (instead
of the pop bumper sound). And the upper playfield standup targets will
give the Tilt sound.
S16 comes from a lamp driver transistor Q10 (MPS-A13) on the driver board. This transistor is an add-on function to give more sound abilities (giving the sound board a total of 32 different sound triggers). The S16 sound is triggered differently than the S1,S2,S4,S8 sounds. Basically S16 is triggered like a playfield lamp, since it is driven by a MPS-A13 lamp driver transistor on the driver board. Hence it is controlled by the Z3 chip (74175), which is triggered by the U6 CPU board RIOT (6532).
The S32 sound line (the sixth line) works exactly like the S16 sound line. That's the bad news. The good news is S32 is not implement on most System80 games. In fact I can't think of single game that uses it. Therefore you can pretty much ignore S32.
More Sound Board Explainations.
The Sound/Speech board is a little computer.
This board has a 6502 microprocessor and 6532 RIOT just like the CPU board.
Problems with sound are best broken down into situations and solutions.
Most people present me with sound problems and this is the best way to
narrow down the solution, but a breakdown of things to check is listed below:
Testing Sound1 to Sound32 using the internal sound/speech board test.
Because all the sounds are generated by the S1,S2,S4,S8,S16 sound
lines (S32 is not used), Gottlieb has a sound/speech board test to activate
these sounds individually. If even one of the six sounds
is missing, this can cascade and make many sound not
work for the game (it should be noted that most system80
games do not use the Sound32 line).
With this in mind, now the next sound/speech board test can be performed.
The following assumes you have a U14 speech chip
installed (most games except Haunted House). If you don't have
a U14 chip, skip down to the
Checks part of this document for the
non-speech version of this test.
The sound/speech board connector with the pin numbers labeled.
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Testing the Sound/Speech board with Game in Attract Mode.
- Power the game on.
- Attach one end of an alligator test lead to ground.
- Momentarily touch the other end of the alligator test lead
to the sound/speech board A6J1 connector:
- A6J1 Pin 8 - sound board plays a game tune for S1.
- A6J1 Pin 9 - sound board plays a game tune for S2.
- A6J1 Pin 11 - sound board plays a game tune for S4.
- A6J1 Pin 12 - sound board plays a game tune for S8.
- A6J1 Pin 2 - sound board plays a game tune for S16.*
- A6J1 Pin 4 - sound board plays a game tune for S32.* Note MOST system80 games don't use this sound, so if no sound comes, that is OK. This is unlike the other sound test above where the game says "thirtytwo".
Another way to test the sound board is with the game in attract mode (or game mode, but it's easier in attract mode as the sound/speech board should be silent). This test works better than the above test (using the DIP switches) if your game isn't a talking game (like say Haunted House).
More on Missing Sounds.
If any of the sounds S1 to S16 are *not* present in the above test,
then the problem is with the sound board itself (opposed to the
path from the CPU board, to the Driver board, to the Sound board,
which is used for S1-S8 to activate those sounds).
If all the sounds do test correctly, the problem is in the communications between the CPU board, the driver board, or the connectors going between these boards and to the sound/speech board. Components on the CPU board and/or driver board could also be damaged. The remainder of this document covers these details.
If the sound board itself is at fault, there are some easy things to check/replaced. First is sound/speech board chip U16 (7404) and U17 (74LS30). These two chips are the input inverters leading to the U15 RIOT chip. Often the U16 (especially) can fail. Next check the U15 RIOT (6532) chip. This is the same RIOT chip used on the CPU board, so you can swap two 6532 chips and see if any changes result. Next check the two sound/speech EPROMs. Normally if the sound board does anything, these are probably fine. Finally, if the game will not "talk" (and it is a talking game, which not all system80 games are), suspect the speech chip U14. Non-talking games will be missing this chip completely.
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System 80 games with this board fitted generate 5 separate sound signals –
Sound 1(S1), Sound 2(S2), Sound 4(S4), Sound 8(S8) and Sound 16 (S16).
The sound board also has provision for a Sound 32 (S32) but this is not
often used. A combination of these signals generate each individual sound.
For example, Sound 1, Sound 2 and Sound 16 generate the top spinner sound on Black Hole
Schematic of the System80 CPU board, where sounds S1,S2,S4,S8 originate.
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Sounds are triggered from the CPU board (aka "A1"). S1,S2,S4 and S8 originate
from the 6532 RIOT (U6). They then pass through a 7404 (Z27) then a 7408
(Z31) and onto the CPU connector A1J4. Pin 12 from chip Z27 is the sound enable
line.
Sound16 and Sound32 are generated from the lamp circuit on the driver board. From the CPU RIOT 6532 (U6) signal D53 comes from the CPU at lamp control 7417 (Z32) and signal LD4 comes from lamp latch control 7404 (Z34) then both pass onto the CPU A1J4 connector.
Schematic of the System80 Driver board, where sounds S16,S32 originate.
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Power up the game and start a new game with the playfield glass off.
Using a logic probe check for a pulse on pins B,A,Z &Y (S1,S2,S4,S8)
whilst triggering sounds on the playfield. These are the four pins on the
right front of A1J4. To test S16 check for a pulse on pins 5 and E of A1J4
whilst triggering sounds on the playfield.
If you are missing pulses I’d replace the RIOT (U6) if you have a spare. However you can work out which sound is missing and step back through the associated chips checking for a pulse.
If you are having problems with sound fading away after a period of time check again after the machine has been powered up for a while. Also check that Z27,Z31,Z32 and Z34 are not getting hot – this is often a sign of a chip failing.
Testing the Data Pathway, Easy Method.
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After the sound/speech board itself is tested (as described above),
it's best to test the pathway from the CPU board to the Driver board
to the Sound/Speech board. This will test the chips and connectors
in this pathway. There is no sense changing chips if the connectors
are at issue, or vice versa. And this test will identify these
problems in a very easy manner.
- Step 1: Test the Sound/Speech board. This is described above. If the sound/speech board is missing any sounds S1 to S16, stop now. Fix or replace the sound/speech board.
- Step 2: At the driver board find chip Z13. Game on and in attract mode. Using an aligator test lead with one end connected to ground, touch the other end of the lead to Driver board chip Z13 pin 2 (s1), pin 4 (s2), pin 6 (s4), pin 7 (s8). A game sound should be heard for each sound S1 to S8. These are the output pins of Z13, so this tests the connection from the driver board to the sound/speech board. If any sound is missing, check the driver board A3J5 connector (upper left) pin 6 (s1), pin 5 (s2), pin 1 (s4), pin 7 (s8). If OK examine the sound board connector A6J1 pin 8 (s1), pin 9 (s2), pin 11 (s4), pin 12 (s8).
- Step 3: At the driver board find chip Z13. Game on and in attract mode. Using an aligator test lead with one end connected to +5 volts (I use the POSITIVE lead of CPU board capacitor C1 next to connector A1J1), touch the other end of the lead to Driver board chip Z13 pin 1 (s1), pin 3 (s2), pin 5 (s4), pin 9 (s8). A game sound should be heard for each sound S1 to S8. These are the input pins of Z13, so this tests the chip Z13 on the driver board.
- Step 4: (Does not work for Black Hole.) At the driver board find chip Z3. Game on and in attract mode. Using an aligator test lead with one end connected to ground, touch the other end of the lead to Driver board chip Z3 pin 7 (s16). A game sound should be heard for sound S16. This is the output pin of Z3, so this tests transistor Q10 (MPS-A13) and the connection from the driver board to the sound/speech board. If this sound is missing, replace Q10 and check the driver board A3J2 pin 9 connector (lower right). If OK examine the sound board connector A6J1 pin 2 (s16).
- Step 5: At the CPU board find chip Z31. Game on and in attract mode. Using an aligator test lead with one end connected to +5 volts (I use the POSITIVE lead of CPU board capacitor C1 next to connector A1J1), touch the other end of the lead to CPU board chip Z31 pin 6 (s1), pin 3 (s2), pin 11 (s4), pin 8 (s8). A game sound should be heard for each sound S1 to S8. These are the output pins of Z31, so this tests the connection from the CPU board to the driver board. If any sound is missing, check the A1J4 to A3J1 connector.
- Step 6: At the CPU board find chip Z31. Game on and in attract mode. Using an aligator test lead with one end connected to +5 volts (I use the POSITIVE lead of CPU board capacitor C1 next to connector A1J1), touch the other end of the lead to CPU board chip Z31 pins 4&5 (s1), pins 1&2 (s2), pins 12&13 (s4), pins 9&10 (s8). A game sound should be heard for each sound S1 to S8. These are the input pins of Z31, so this tests the chip Z31. Note you are touching the aligator test lead to *two* pins of the Z31 chip at the same time. This is an ADD chip, so for the output to trigger both chip legs must go high at the same time.
The only thing left in the chain to test are CPU chips Z27 (7404) and RIOT U6 (6532). Unfortunately this can't be done with just a test lead. Must do this with a logic probe as described below in this document. The easy way to test the U6 RIOT chip is to swap it with U5 or U4 (assuming all are socketed). If any change is noted, this indicates a bad 6532 RIOT chip.
The CPU to Driver board connector – A1J4 to A3J1
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This connector is a source of many problems on System 80 games
including sound issues. It is frequently found damaged from CPU board battery corrosion and
should always be inspected for signs of corrosion and dull or bent pins.
If it is not squeaky clean it’s going to cause problems. Clay’s site
covers the procedure to replace pins completely-
marvin3m.com/sys80/index1.htm
If this connector looks OK I’d still suggest continuity testing for the connectors carrying the sound traces and also check the driver board connector A3J1 pins B (S1), A (S2), Z (S4), Y (S8) for a pulse with a logic probe whilst triggering sounds on the playfield. As these connectors are at the rear of the driver board and hard to get to it may be easier to check them at Z13 on the driver board - Z13 pins 2 (S1), Z13 pin 4 (S2), Z13 pin 6 (S4), Z13 pin 8 (S8).
For Sound 16 check CPU to driver board connnector pins E (D53) and pin 5 (LD4) on A3J1 for a pulse with a logic probe whilst triggering sounds on the playfield. Again it may be simpler to check these signals on the driver board at Z3 pin 9 (D53) and Z1 pin 13 (LD4).
I’ll stress again that this connector is a pain and it is crucial to ensure it is connecting well. I thought mine was clean until I wobbled it with the game on and got intermittent sounds occurring - a sure sign of a bad connector.
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Sounds S1,S2,S4,S8 pass though a 7404 (Z13) on the driver
board. Z13 is an inverter that converts sound signals from High to Low or
visa versa. The sounds enter Z13 pin 2 (S1), pin 4 (S2), pin 6 (S4), pin 8 (S8).
They exit on Z13 pin 1 (S1), pin 3 (S2), pin 5 (S4), pin 9 (S8).
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This is a simple chip to test. For example if a high signal is present on Z13 pin 1 then a low should be present on Z13 pin 2 - a logic probe will determine this. Use the same procedure for the remaining sounds. If in doubt change the chip and socket in a new one.
Another crude test is to check if the chip is hot - it shouldn’t be.
Sound 16 goes through another section of the driver board. It arrives at the driver board at A3J1 Pins E (D53) and 5 (LD4). From there D53 goes through Z3 pin 9 and LD4 goes through Z3 pin 13. It outputs through Z3 pin 7 (74175) to a transistor Q10 (MPS-A13), then onto connector A3J2 pin 9.
Check the connector A3J2 pin 9 with a logic probe to test S16 – you should see a pulse when activating sounds on the playfield. My test for this is to flick the spinner for the entrance to the black hole - it uses S1,S2 and S16 to generate the sound.
If driver board Z3 was faulty you should have some controlled lamps also affected- although it is possible that just one gate is faulty, but unlikely. More likely is the Q10 transistor – but again the failure rate is low. You can check this transistor using Clay’s method- marvin3m.com/sys80/index2.htm#test
Schematic of the System80 driver board, where sound S16 originates.
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Finally it’s worth checking the pins in connector A3J5 pins 6,5,1,7,
and A3J2 pin 9. Again they should be shiny, not dull or
corroded. Replace suspect pins as per Clay’s site -
marvin3m.com/sys80/index1.htm#connect
If you’ve got to this point and found no fault them you can reasonably assume that you have no problem with the CPU board, the driver board or the connections between the two. Now the fun begins.
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What it does: This jig allows you to "see" the sound signals as they are
generated. It also lets you generate sound without having to utilise the
playfield.
- 5 x 1.7-2.8V LEDS (Different colours for each make it easier)
- 5 x 1K resistors
- 5 x momentary make Push Button Switches
- 1 x Breadboard or punched laminate board – at least 3" X 5"
- 7 x 24" long wires- (wire wrap ok and 7 different colours help)
Each led represents each of the sound signals. The leds light as each signal is sent and confirms that both the CPU and driver board are handling the sounds correctly. It allows you to track intermittent sound signals (such as caused by faulty connectors or overheating chips). For me it confirmed that my problem lay within the sound board itself as all sound signals were present regardless of whether the incorrect sound was played or not.
Components required:
Circuit Diagram:
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This jig gets attached to the driver board – whilst still leaving the
sound board plugged in.
I built this in around 30 minutes based on a design from Clay’s TOP videotapes. I solder tacked the sound leads onto the board at the points shown on the circuit diagram but you could use test clips. I took the +5VDC straight from the power supply board (A2) test point and attached the ground to the common ground wire implemented by Clay’s and John Robertson’s System 80 ground modifications. However any common ground will do.
You can use this Jig to test sounds without a game in play. As each button is pressed you’ll get the corresponding sound played. Note that combinations of these sounds produce all the various game sounds- see the Black Hole matrix diagram below.
| Sound | s1 | s2 | s4 | s8 | s16 |
| Coin Tune | x | x | |||
| Start sound | x | ||||
| Background Music/Lower PF wind noise | x | x | |||
| Upper PF Target in G-Force sequence + lower Targets | x | x | |||
| Upper PF Target not in G-Force sequence | x | x | |||
| Extra Ball sound | x | ||||
| Game Over sound | x | ||||
| Upper PF random sound 1 | x | ||||
| Upper PF random sound 2 | x | x | |||
| Upper PF random sound 3 | x | x | |||
| Upper PF random sound 4 | x | x | x | ||
| Upper Pf Spinner (Entry to lower pf) | x | x | x | ||
| Lower PF bonus count sound | x | x | |||
| Lower PF scoring Random sound 1 | x | x | x | ||
| Lower PF scoring Random sound 2 | x | x | |||
| Note: Upper PF Random sounds used by 10 Point targets upper PF, upper three lanes on top PF, 1000 point rollover left hand top PF, Pop Bumpers, Slingshots, Yellow Spot targets for captive ball. Lower PF uses all random sounds except captive hole and targets | |||||
| Speech | s1 | s2 | s4 | s8 | s16 |
| Tilt | x | x | |||
| Slam Tilt (Oh No) | x | x | x | x | |
| Captured | x | x | x | x | x |
| Re-entry attempt has failed | x | x | x | ||
| Re-Entry accomplished | x | x | x | x | |
| Shoot for Special | x | x | x | x | |
| Shoot Captive Hole | x | x | x | x | |
| Enter Gravity Tunnel | x | x | x | ||
| G Force Accelerated | x | x | x | x | |
| Complete Bank for Re-entry | x | x | |||
| Lost (Entry to Lower PF) | x | x | x | ||
You’ll find it is near impossible to press say four buttons at the same time. To overcome this short out the sound lines AFTER the buttons – eg to play S1,S2 and S3 together short the three lines and press any of those three buttons. I used a piece of wire wrap and wound it round those lines I wanted shorted.
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Who knows what the designer of this thing were thinking. I suppose it
was built because of the limitations of available technology but probably
because it was cheap! There are three revisions of this board- all are
interchangeable.
The sound/speech board A6.
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This board has it’s own unique power supply board (A7) supplying
30VDC (A6P1-Pin10) (for the LM379 amp) 12vdc+ (A6P1-Pin 1) and 12VDC-
(A6P1-Pin 3). The board also receives +5VDC (A6P1-Pin 5) straight from the
main power supply board (A2). Check out all these voltages before you
proceed.
Schematic of the System80 sound/speech board.
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The sound board has five distinct sections as shown in the diagram.
The Green area is the Sound Input section of the board. This section receives
and readies the incoming signals for the logic section. The Pink area is the
logic section of the board. This section decides what to do with the signal with
instructions from the ROMs The Blue area is the speech output section of the
board. It processes the speech requests from the logic section and instructs the
SC01 speech chip (U14) to produce the speech The Yellow area is the sound
output section of the board. It processes the sound request from the logic section
and produces all the sounds The Red area is the Speech and Sound Output section
of the board. It receives both speech and sound, amplifies them and sends the results
to the speakers
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Problem Parts.
Before we start there are several parts that are unavailable for this board and some that are extremely hard to get.
The SC01 (U14) speech chip is no longer available and has been for some time. If you have no speech whatsoever it’s possible this chip is dead and it’s time to start looking for a replacement board (or you have a non-talking game like Haunted House).
The Digital to Analogue converters (DAC) 1408-6P (U19 and U20) are no longer made and extremely hard to find. A replacement can be found at Jameco.com under chip number DAC0808LCN, or Jameco part number 14947.
The main amplifier for the sound board LM379 (U23) is no longer made but still available from GPE - www.greatplainselectronics.com. Alternatively Kirb has come up with a modern replacement - www.geocities.com/kirbseepe/repairAMP.html. Both of these are far superior to Gottlieb’s attempts at a daughter board and messy mods
The RIOT 6532 (U15) and MPU 6502 (U3) aren’t made any more but GPE still has these - www.greatplainselectronics.com. The RIOT’s are also used on the CPU board so having a few spares is worth while as they often fail.
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Sounds enter the sound board from connector A6P1 – Pins 8 (S1), 9
(S2), 11 (S4), 12 (S8) and 2 (S16). Sounds 1,2 4 and 8 are inverted by a
74LS04 (U16) and also go to a 74LS30 (U17) which then pass them to the
RIOT 6532 (U15). Sound 16 passes though a lamp driver interface LM393
(U24) which ensures that a low signal for this sound is delivered to U16.
Sound 1,2,4,8 Inputs.
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Sound 16 Input
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I used the sound test jig to generate the sounds here but you could activate them from the playfield.
Test to see that the sounds are coming into the board. Check for a pulse with your logic probe whilst triggering sounds on pins 8 (S1),9 (S2), 11 (S4), 12 (S8) and 2 (S16) on the A6P1 connector on the sound board. If any of these signals are missing check the pins in the connecting plug to the board in the same manner mentioned earlier and replace any suspect pins.
If the sound signals are all present now check U16 pins 13 (S1),11 (S2),1 (S4),3 (S8),9 (S16) for a pulse whilst activating sounds. Note whether they are high or low. Now check the other side of the signal on U16 for the opposite results to what you’ve just found – Pins 12,10,2,4,8 in order. EG- If you had a high on pin 13 you should see a low on Pin 12. If S1,2,4 or 8 are missing on the output side replace the chip.
If S16 is not present check U24 Pin 7 for a pulse. If no pulse is present or it doesn’t change from high to low replace the chip.
If all signals are present repeat the tests on the RIOT (U15) Pins 8,9,10,11,12. These are the inputs to the riot and if not present may suggest a broken track on the board.
I normally replace the RIOT 6532 (U15) as one of my first steps when the board plays up- but I have the luxury of spares. To further test this chip with your logic probe, Pin 29 should go low when sounds are activated. Pin 29 is the IRQ line and tells the MPU to read ports PA0-PA5 (the sounds into the RIOT).
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Here’s where some real electronic engineer knowledge is needed –
that’s not me. Sound and speech instructions are stored in the Rom’s
(U5 & U6). These in turn feed these to the MPU 6502 (U3). The MPU then
feeds the Device Select 74LS138 (U4).
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The G1 line is tied High whilst G2A and G2B are tied Low. Devices are
selected according to the binary condition (0 or 1) of inputs from the MPU
at A (U4 Pin1) B (U4 Pin2) and C (U4 Pin3). The following chart explains
the logic used.
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To check that the board is booting test the MPU 6502 (U3) with a logic
probe. Pin 40 should be low when the board first starts and then change to
high. The pulse will be momentary as the timing is 30ms so you’ll need
to have your logic probe attached and on the pin before you power up the
game. Next check the RIOT 6532 (U15) pin 34 the same way. The RIOT is
known to fail and also cause other symptoms such as missing or incorrect
sounds if faulty.
Another test for the MPU (U3) is Pin 4 should go low when sounds are activated. It is the IRQ line for the MPU.
Check the clock is ok by testing for a continuous pulse at Pin 37,3 & 39 of the MPU 6502 (U3). If there is no pulse at the MPU check the crystal (Y1) for a pulse then the 74LS74 (U2 – Pin 6). If there is a pulse at the crystal but not U2 suspect the 7404 (U25) first- this "squares up" the output from the crystal then U2.
As to the device select chip (U4) you can test for a pulse but as the logic is so complex especially when dealing with an intermittent fault, I’d simply socket and replace it- they are cheap and common. The test will take you longer than it’s worth I haven’t thought of a way to test either the ROMs (U5 and U6) without a scope so I’d have spares handy to substitute. However the sound board test procedure should indicate if these are faulty in most cases- not always.
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This is where the designer of this board was seriously off his face. It’s
really quite clever but unnecessarily complex compared to what modern
machines use.
This circuit all revolves around the now defunct SC01A chip (U14). This chip produces phonemes (I had to look this word up)- basic units of speech. Vary the clock frequency to it (Pins 15 & 16) and it speaks- Wow! It can also produce sound effects the same way.
See the diagram where I’ve outlined the sections of the board and look at the speech output section. Basically two latches (7475 – U11 and U18- controlled by U10) receive data from the MPU , pass it through a DAC (U19) which converts the signal into a proportional current. This then passes through a frequency adjust LM741 (U21), a couple of transistors (Q1 and Q2) then into the speech chip (U14) at pins 15,16. This is the variable clock signal for the speech chip. The pot R16 controls the speech volume. The R6 is a "frequency adjust" pot, and R13 is an "amplitude adjust" pot.
Data is also sent to the speech chip from MPU to the Level Shift 74LS05 (U13), pulled up by a Dip resistor (RP1) and into pins 9 to 14 of the speech chip.
Voice and effects pitch is varied from the MPU by making Pin 13 of Latch 7475 (U9) high then transferring the data to U12 then onto Pins 2 & 3 of the speech chip(U14).
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If you’ve got sounds and no speech then this is the area to examine
once you’ve established that sounds are arriving from the A1 CPU board
and that the sounds are passing through the input section of the board OK.
Chips to suspect are the latches (U11, U18) then the DAC (U19) then
the Frequency adjust chip (LM741). U10 has been known to fail but also
controls sounds so it would be one gate only. I’ve never heard of the
transistors going but I suppose it is possible. After this you’re
possible facing a dead speech chip (U14) – and it’s time to source
another board.
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Sound effects start the same way as speech- two latches (7475 – U7
and U8- controlled by U10) receive data from the MPU and pass it through
a DAC (U20). They then pass through an analog inverter LM741 (U22) with
R13 as a trimpot and then onto the main amp (U23) passing through R15
where you can adjust the sounds volume.
If you’ve got speech but no sounds then this is the area to examine once you’ve established that sounds are arriving from the A1 CPU board and that the sounds are passing through the input section of the board OK. Chips to suspect are the latches (U7 & 8), the DAC (U20) then the LM741 (U22). This is a small circuit so it’s easy to fix.
Speech and Sound Output section
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This is a common area of failure due to the amplifier used –
LM379s (U23)- and it’s 30VDC voltage requirement.
Basically this section of the board is two trimpots (R16 & R15) and the amp. R16 controls the speech volume. R15 controls the sounds volume. The manual clearly states you shouldn't alter these but provided the changes you make are not large it will probably be ok. I never touch the sound volume but turn up the speech to try and equal the sound volume- it always seems to be set lower.
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If you have no sound and speech and you have checked that all sounds
are coming from the A1 CPU board then this area is worth checking. It’s
usually pretty obvious if the amp is working or not. If you have no sounds
or speech- turn up the volume- if you hear the hum increase chances are
the amp is OK. In the event that it’s dead you can still purchase them from GPE -
www.greatplainselectronics.com
or Kirb has designed a modern replacement
www.geocities.com/kirbseepe/repairAMP.html.
Speech/Sound Board DIP Switches
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Oddly, some strange sound problems can be fixed by just
flipping all the sound/speech board DIP switches a
few times. If in doubt, put them all to OFF.
- DIP S1- used to do self test
- DIP S2- Not used
- DIP S3 and S4- Used for attract sounds and how often they are played. Both off is no attract sounds. Both on is maximum time between sounds.
- DIP S5- background sound enabled during game play if on
- DIP S6- Not used
- DIP S7- Not used
Game Over Sounds.
On Mars God of War (MGoW), game plays fine and sounds fine. But at game
over the background sound wont shut off. Game passes all sound tests and
ground mods have been done. Is there a solution?
The answer is to try turning CPU board DIP switch 25 on, and see if anything changes. Although the MGOW manual states DIP 25 is not used, there is other info provided by Gottleib which states differently. The back page of the June 1981 Gottlieb On-Target newsletter alludes to this. It actually states that if CPU DIP 25 is off, and the game is slam tilted, the BG sound will keep playing. And on Sys80 machines after MGoW, which use a different sound board, DIP 25 is marked with "MUST REMAIN ON." This does not apply to Sys80As though, because DIP 25 controls a completely different option on them.
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The following checks (tests) are taken right from the manuals for the game.
I used games I had manuals for, so if yours in not listed, get a manual!
- indicates an operation by the user (you)
# indicates an operation by the sound board
Gottlieb Haunted House:
Haunted House has no U14 speech chip as the game
did not implement speech. So the internal sound test
is a bit different than a talking game:
-Push test button on sound board
#Board will beep 1 tone if the RAM is bad.
#Board will beep 2 tones if sound ROM1 is bad.
#Board will beep 3 tones if sound ROM2 is bad.
#Board will beep 5 tones after a pause if everything so far is OK
(repeats until you do something)
-Start sound trigger test. The book asks you to ground the pins
on the P1 connector, but I find it much easier to ground the pins
on the U16 chip. Take a metal pick tool and attach a jumper from
it to ground. Use this to poke the pins of the chip. Note that
pin 14 has +5 volts on it!
-ground pin 1 of U16 (s4)
#Board should beep 5 tones
-ground pin 3 of U16 (s8)
#Board should beep 5 tones
-ground pin 5 of U16 (s32)
#Board should beep 5 tones
-ground pin 9 of U16 (s16)
#Board should beep 5 tones
-ground pin 11 of U16 (s2)
#Board should beep 5 tones
-ground pin 13 of U16 (s1)
#Board should beep 5 tones
-Push test button
#Board should beep one long tone
-Push test button
#board should stop beeping.
Test is over. Take notes on what works or does not work.
Gottlieb Volcano or Mars God of War:
-Push test button on sound board
#Board will say "ram test fails" if the RAM is bad.
#Board will say "eprom 1 fails" if sound ROM1 is bad.
#Board will say "eprom 2 fails" if sound ROM2 is bad.
#Board will say "turn DIP switches off" if everything is OK so far
-Turn all sound board DIP switches to the off position.
#Board will say "thank you- turn all dip switches on" if the board can
"see" the DIP switches.
-Turn all sound board DIP switches on.
#Board will say "thank you" if all the dip switches can be "seen". A test sound will repeat.
-Turn the DIP1 switch off.
-Start sound trigger test. The book asks you to ground the pins on the
P1 connector, but I find it much easier to ground the pins on the U16 chip.
Take a metal pick tool and attach a jumper from it to ground. Use this
to poke the pins of the chip. Note that pin 14 has +5 volts on it!
-ground pin 1 of U16 (s4)
#Board should say "4"
-ground pin 3 of U16 (s8)
#Board should say "8"
-ground pin 5 of U16 (s32)
#Unknown since this is not used. It may say "32"
-ground pin 9 of U16 (s16)
#Board should say "16"
-ground pin 11 of U16 (s2)
#Board should say "2"
-ground pin 13 of U16 (s1)
#Board should say "1"
-Push test button
#Board should say "test complete"
Test is over. Take notes on what works or does not work.
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