RCA 18V100 Keyboard Tests, Malfunction. If Tester is unavailable, the keyboards can be, Studio

Page 8

The keys of Keyboard B "write" on the screen according

to the white arrowheads on the keyboard (Fig. 15). To form

an interesting pattern, press "Clear" key, then A2, B2 15

times, B6 once, and then BO. The memory stores up to 130

key entries or "moves". After 130 moves, the computer auto'

matically starts to repeat the pattern. For 129 or fewer moves.

Key BO must be pressed to start the repeat cycle.

Keyboard Tests

If "Tester I" cartridge is available, use it to isolate keyboard

malfunction. If Tester is unavailable, the keyboards can be

tested using the built-in "Addition" game:

Step 1 Punch up "Addition" game (Key A5). Sound switch

must be "on".

Step 2: When the three-digit number appears on screen,

enter a series of wrong answers, beginning with A1 As each

button is pressed, the beeper sounds, indicating the particular

button is operational. The beeper sounds only during the five

seconds that the random-orderdisplay is on screen. Usually,

the entire keyboard can be checked during the five-second

display. If any key fails to sound, that key is faulty and the

entire keyboard should be replaced.

KEYBOARD A

KEYBOARD B

nanaha B

Studio II

a©

CLEARKEY#0

STARTS

COMPUTER

PATTERN

Figure 15. Keyboard "B" Moves Spot According to White

Arrowheads on Panel

"Doodles" Function

Press "Clear" key. Press A1 Single dot appears on screen at

lower left corner. Use keys on Keyboard B to move spot

according to white arrows on panel (Fig. 16). Key B5 leaves a

trail as player "writes" with Keyboard B. Pressing Key BO

leaves no trail. Retrace steps to erase lines already written.

Figure 16. In "Doodles", etch a sketch electronically with the

"B" keyboard

 

 

am

ana

 

 

 

 

 

 

 

13D

 

 

 

 

KEY #5 START

 

 

 

 

 

 

 

\___

 

 

 

 

 

 

r\~~.

io

ni

B

 

 

 

 

\

 

 

 

 

 

 

 

o\po

 

 

 

 

 

PLAYER A

 

DDD

 

Studio 11

 

 

PLAYER B

ENTERS

Q

 

DDD

DDD

]

ENTERS

 

DDD

 

©

DDDD

'

SUM

 

 

a

 

 

 

 

 

I

 

<

CLEAR

 

 

 

^

 

 

 

 

 

Figure 17. Using "Addition" to Check Keyboards

"Double-Hit" Keyboard Complaints

Some early production units (Serial Nos. 37125 and lower)

occasionally exhibit a keyboard malfunction termed "double-

hit" when Studio II operates in the "Patterns" mode (un-

wanted dots appear on the screen, and the beeper sounds

twice for only one key entry). The only remedy for double

hits is keyboard replacement.

Coaxial Cable Tests

The coaxial cable carries modulated RF from the console

and DC from the power unit. Use an ohmmeter to test the

cable from the plug end (Fig. 1 8). A good cable measures 5 to

CABLE CONNECTOR

 

I—/©n

 

Z>««">

N s~^

OHMMETER

 

4-

 

""J

Figure 18. Checking Continuity of Co-ax Cable

*J

J

8

Image 8
Contents Itc/i Table of Contents Power Supply Keyboard ON/OFF Indicator LightSelector Switch SwitchTest Procedures To Antenna PowerSystem Checking System ConnectionsOne at a time of Keyboard A, and then Keyboard B. As 9a appears on screen immediately, and TesterBoard must be replaced Overall Block Diagram of Studio II System £ sjThree Numbers to be Added Punch up Addition game Key A5. Sound switch Must be on Keyboard TestsMalfunction. If Tester is unavailable, the keyboards can be Enter a series of wrong answers, beginning with A1 As eachPletes the DC circuit between the console and power supply With the switch in the TV position, it disconnects the conComponents Coaxial cable from the console to the twin lead and comStudio II Console Assembly Component Replacement Procedure Console DisassemblySaw. See for dimensions Minimize radiation of modulated carrierClock Frequency Adjustment Procedure Scope Time-Base Locked to 60Hz Power LineReconnect black, white and yellow leads from PC board Milliseconds or more sync on Line and vertical inputExchange Plan Description PC Board Packing and ShipmentReturn Shipping Label RCA Distributor and Special Products Division Deptford NJ Form 3E4589