Obviously it needs a full check up and test.  It’s 28-29 years old and these things need to be handled very carefully.  It’s just a shame  that I can’t play as well as I could when I was 17.  Best start practicing!

Just for reference, here are a few Defender Settings, accessed using the three buttons inside the coin slot:

BOOKKEEPING AND EVALUATION TOTALS (Functions 1-7)

1. In game over mode, set switch to AUTO-UP and depress ADVANCE. The CRT indicates Function 1 and total left chute coins.
2. Record audit totals and depress ADVANCE for functions 1-7. To review a total that has been advanced past, set switch to MANUAL-DOWN and depress ADVANCE.  Functions are displayed one at a time as follows:-

Function    Total    Description
——————————–
1          0      (Total) COINS LEFT
2          0      (Total) COINS CENTER
3          0      (Total) COINS RIGHT
4          0      TOTAL PAID (Games)
5          0      (Total Bonus) SHIPS WON
6          0      TOTAL (Play) TIME (Minutes)
7          0      TOTAL SHIPS (Played)

3. Operate ADVANCE to display Function 28, SPECIAL FUNCTION. From Function 28 you can return to game over or zero audit totals and return to game over.
4. With switch set to AUTO-UP, perform a. or b. as desired.

a. To return to game over depress ADVANCE.
b. To zero audit totals and return to game over, operate HIGH SCORE RESET to indicate “35″ on CRT Function 28 and then depress ADVANCE.

GAME ADJUSTMENTS (Functions 8-27)

In game over mode set switch to AUTO_UP and then depress ADVANCE. The CRTindicates Function 1 and total left chute coins.
To raise Function number on CRT, operate ADVANCE pushbutton with switch set to AUTO-UP. To lower Function number operate ADVANCE with it set to MANUAL-DOWN.
With desired Function indicated, raise adjustment value by operating HIGH SCORE RESET with switch set to AUTO-UP; lower value by operating HIGH SCORE RESET with it set to MANUAL-DOWN. Value left on CRT is new  setting.  For values, see below and, for pricing, Table 1.

Function   Factory Setting   Description
—————————————-
08           10000        BONUS SHIP LEVEL (0=No Bonus Ships)
09               3        SHIPS PER GAME
10               3        COINAGE SELECT
11               1        LEFT COIN MULT
12               4        CENTER COIN MULT
13               1        RIGHT COIN MULT
14               1        COINS FOR CREDIT
15               0        COINS FOR BONUS
16               0        MINIMUM COINS
17               0        FREE PLAY (Set to 1 for Free Play)
18               0        STARTING DIFFICULTY (0=LIB; 1=MOD; 2=CONS)
19              10        PROGRESSIVE WAVE DIFFICULTY LIMIT (4-25)  e.g. 5-LIB; 10=MOD; 15=CONS;
20               1        BACKGROUND SOUND (0=OFF; 1=ON)
21               5        PLANET RESTORE WAVE NUMBER
22               0        NOT USED
23               0        NOT USED
24               0        NOT USED
25               0        NOT USED
26               0        NOT USED
27               0        NOT USED

4. Repeat steps 2 and 3 until all desired adjustments have been made.
5. Operate ADVANCE until 28 0 SPECIAL FUNCTION is indicated on CRT. From Function 28 you can return to game over or restore factory settings. Perform step 6 or 7 as desired.
6. To return to game over, depress ADVANCE with switch set to AUTO-UP.
7. To restore factory settings and zero audit totals:

a. Operate HIGH SCORE RESET in AUTO-UP to indicate “45″ on CRT Function 28.
b. Depress ADVANCE. The game returns to audit Function 1.
c. Set switch to MANUAL-DOWN and depress ADVANCE to indicate Function 28 on the CRT.
d. Set switch to AUTO-UP and depress ADVANCE.