Running System 4-6 Games on a System 7 MPU board:

 

Any System 4-6 Game will work on a System 7 MPU.

Williams added backward compatibility with configuration jumpers when they created System 7.

It meant operators could hold spares of the System 7 MPU board going forward, and it could still work in the earlier games.

The jumper settings for using a combined Flipper ROM have been documented at   pinrepair.com ;  let’s call that Method A.

Here are some additional explanations and an alternate Method B for true System 3-6a MPU emulation.  This works for Sys 3-6 games,

and there is also a Method B for Firepower (80) below.  Firepower was where my personal pinball obsession began.

 

Normal System 3-6 Game on a System 7 MPU -Method A:

Uses the same jumper settings as System 7 games.

3-4-5,  6-24,  7-8,  9-10-28,  11-12,  13-14-15,  16-17,  18-1920-21,  22-23,  26-27.

FACTORY JUMPERS ARE:  2, 25, 29-30    RED means IN (jumpered) and Black means OUT.

    1.  Leave the MPU board jumpered for a standard game, as shown just above.   An explanation of jumper functions is here.

    2.  Download the right color “Combined Flipper ROM” code here:     Sys4-Sys6 Flipper ROMs for Sys7 MPU

    3.  Burn a 2532 EPROM with the Flipper ROM 1+2 code and that goes in IC17.
    4.  Finally put the Standard 2716 Game ROM in IC14.  IC20 and IC26 are not used.    

          Done.  It’s not very hard to do. 

 

Press the diagnostic Switch on the MPU:

The System 6 Game ROMs will flash a "u" twice on the 7-segment display twice, and both LEDs (if installed).

The Sys 7 numeric diagnostics will not be available without the Williams test chip in IC17, or a complete set of System 7 EPROMs.

 

Normal System 3-6 Game on a System 7 MPU - Method B:

This is System 6 MPU emulation, and uses the original 2716 ROM code in the correct locations.

3-4-5, 6-24,  7-8,  9-10-28,  11-12,  13-14-15,  16-17,  18-19,  20-21,  22-2326-27.

FACTORY JUMPERS ARE:  2, 25, 29-30   As before: RED means IN (jumpered) and Black means OUT.

    1.  Set up the game with the special jumper settings given just above.

    2.  You don’t need special EPROMs. Put the Game ROM (or a 2716 EPROM) in IC14.

    3.   Flipper ROM 1 (or a 2716 EPROM) goes in IC20 , as usual.

    4.   Flipper ROM 2 (or a 2716 EPROM) goes in IC17 , as usual.

          Done.  Might be useful when you have a soldering iron for the jumpers but no access to a EPROM burner.

          Of course, the same ROM set (Flipper1, Flipper2, and Game EPROMs) work in a System 3-6 MPU board.

          Don’t mess with using Bipolar PROMS, it’s never worth it in the long run.

          This method B will work for all games (except Firepower).   That’s from Hot Tip (Nov. ’77) to Alien Poker (Oct. ’80)

 

Running Firepower ('80) on a System 7 board is an Exception:
First, let’s look at the factory location of Firepower code on a System 6 MPU.

 

Location

Address Range

ROM Type

Name

IC17:

$7800-7FFF

2716     (2K)

Green Flipper ROM 2

IC20:

$7000-77FF

2716     (2K)

Green Flipper ROM 1

IC14:

$6800-6FFF

2716     (2K)

Firepower Game ROM

IC26:

$6400-65FF

(74S)474 (512 byte)

Firepower Prom 3

IC22:

$6200-63FF

(74S)474 (512 byte)

Firepower Prom 2

IC21:

$6000-61FF

(74S)474 (512 byte)

Firepower Prom 1

 

Firepower Method A:    (By far, the best method is to burn a new 2532 EPROM for IC17 and a new 2716 EPROM for IC14)

    1.  Leave the MPU board jumpered for a standard game, as shown underlined here.

    2.  Download all the EPROM code here:    Firepower for Sys7 MPU
    3.  Burn a 2532 EPROM with the custom Green Flipper ROM 1+2 code.  That goes in IC17 , as usual.

    4.  Put the standard System 6 Firepower Game ROM (or 2716 EPROM) in IC20.

    4.   Finally- put a custom 2716 EPROM in IC14 , this is a combination of the PROMS 1+2+3.

 

This is the layout for Method A on the System 7 MPU:

Location

Address Range

ROM Type

Name

IC17:

$7000-7FFF

2532     (4K)

Green Flipper ROM 1+2

IC20:

$6800-6FFF

2716     (2K)

Firepower Game ROM

IC14:

$6000-67FF

2716     (2K)

Firepower Proms  1+2+3

 (Compare this with the factory locations on System 6, notice the starting Addresses have stayed the same).

The game will play as expected, but the diagnostic button on the Sys 7 MPU board does not work (for me) with this ROM setup.

Press the Diag. button and the top LED will stays stuck on (if LEDs are installed), the display shows a character like an “E” without the top segment.

BTW - The decimal equivalent of this display code would be 14, according to the 74LS47 datasheet.  I don’t know why it does this.

 

To do a test, from attract mode you can ground 1J4 pins 2&3 (coin door inputs) together.  See this section for getting into attract mode. 

This is the same as pressing “Advance with the switch set to Manual / Down” from the coin door.

This will get the double flash of the “u” on the display (and both LEDs) - provided everything is working OK.

 

Firepower Method B:    (This uses original COMBO ROM code, with jumper settings to emulate the System 6 MPU board)
Jumper settings given in RED below are only for using the Firepower System 6 COMBO ROM code in a System 7 MPU
3-4-5, 6-24,  7-8,  9-10-28,  11-12,  13-14-15,  16-17,  18-19,  20-21,  22-2326-27.

FACTORY JUMPERS ARE:  2, 25, 29-30   As before: RED means IN (jumpered) and Black means OUT.

    1.  Set up the game with the special jumper settings given below.

    2.  Burn the Firepower COMBO ROM code on a 2532 EPROM. That goes in IC14. *

    3.   Any original Firepower 2716 "Green Flipper ROM 1" goes in IC20 (Green1).
    4.   Any original Firepower 2716 "Green Flipper ROM 2" goes in IC17 (Green2).

* Notice that you burn a 2532 EPROM with the 4K Firepower "COMBO ROM" code. 

This contains the code from the 3 original PROMs 1+2+3 and the Firepower Game ROM.  Code is here.

A 2732 Eprom does not work without some board changes or an adaptor. 

If you make a 2732 to 2532 adaptor, instructions here then you can use the normal 2732 “COMBO EPROM” on the System 7 MPU. 

Then it’s possible to swap the same set (Green1, Green2 and Combo EPROMs) back into a System 6 (or 6a) MPU board.

I wouldn’t recommend making the hacks to a System 7 MPU board to use a 2732 EPROM in IC17, unless you feel you have to!

From my experience, it's just as easy to make the 2732 to 2532 adaptor. And, hey, later on you may want back the flexibility to jumper for a 2716 (or 2532) in IC17.

 

This is the layout for Method B on the System 7 MPU:

Location

Address Range

ROM Type

Name

IC20:

$7000-77FF

2716     (2K)

Green Flipper ROM 1

IC17:

$7800-7FFF

2716     (2K)

Green Flipper ROM 2

IC14:

$6000-67FF

2532     (4K)

Firepower COMBO ROM

 

I have tested Method B on a couple of MPU boards. With both Firepower Method A (IC17) or with this RJH Method B (IC14), you have to burn a 2532 Eprom.

But- the RJH Method B jumper settings work, and the diag. button will work as expected! Which may be important to you.

 

How can I tell if my Firepower (or another) game is running on the MPU)?

You need to do this in all cases on the test bench before putting the Sys 7 MPU board in a game for the first time: 

Always connect a known good Driverboard, once you want to test game function and the “attract mode”.

Be sure you have the correct jumper settings and good Game ROMs installed as above. You cannot test the MPU is working fully without the Driverboard attached! 

With no battery connected, (so with factory settings) you will need put the +12v off and back on from 1J2  pin 9  - like switching the game off and back on quickly.

This should get to the “attract mode” if all is OK.  

 

Here’s what to check with your logic probe, test LED or DMM to see if you are in attract mode and Blanking is at logic high:

    1.   Blanking signal should be +5v (or so) at  test point 4 (TP4) on the System 7 MPU.  Check also at pin 37 (4th pin in from left) of the 80-way connector J1.

    2.   Solenoid 16 (coin lockout) is held low in factory attract .  Check 2J9 pin 6 of the Driverboard, or at the metal tab of transistor Q45.  Should be at GND.

    3.  With Firepower Game ROMs, Solenoid 15 (Flashlamps) will be high and pulse low (Flash) about every 4 secs.  Check this at 2J9 pin 5, or at the metal tab of transistor Q43.

    3.  For other Game ROMs you should still get coin lockout low.  For example, I tested Flash ('79) with Method A and B and recommend using Green Flipper ROMs.

          With Flash you get Solenoid 6 (Flashlamps) pulsing, check for this at 2J11 pin 3, or metal tab of transistor Q25.

 

Test the boards in your game.

If this all looks OK, next step is to put the boards into a game with a remote battery pack.  Leave out fuses F2 (solenoids) and F3 (lamps) to start with.

Start the game and check the in-game diagnostics with the coin door switches and displays.  You may have to switch off & back on quickly the first time.

You may see activity on the displays, Firepower will show 000000 and 550000 in the Player 1 score display alternately if you are in attract mode.

 

    1.   Set coin door switch to Manual Down, and press Advance.  The LEDs (or Display) should flash twice and displays go out.

    2.   Press Advance and switch to Auto Up, you should see a display digits test on all the displays. 0-9

    3.   Press Advance for Lamp Test (01 in credits display).  Press Advance for Solenoid Test (02 in credits display).  Nothing will happen for these as you have taken the fuses out.

    4.   Press Advance for Switch test (03 in credits display).  Now pressing switches on the playfield should indicate something.

 

If this looks OK, switch off game.  Add back the Lamp Fuse (F3) and run through tests 1-4 again.  You should get all playfield lamps flashing Lamp test.

If this works as expected, add back the Solenoid Fuse (F2) and run all tests.  You should get solenoids during the Solenoid test.  See your game Instruction booklet for details.

 

 The original ROM source if any links don't work is Planetary Pinball.com ROM LIBRARY , you can get the original Williams ROM source files there, but not as clearly explained. 

 

Best wishes and Happy Flipping!

-Richard