Zaxxon    High Score Save Kit -- Installation Guide

Step 0: Turn off power to the game

While it may be possible to install this kit without removing your board from its cabinet, you may find it easier to install the kit if you do remove the board. In that case, pay careful attention (or label), any wire connections as you disconnect your board so that you can correctly rehookup the game PCB afterwards. Take note of which side of the PCB edge connector is facing the parts side of the board and which side faces the solder side, This connector is may not be keyed and can be inadvertantly plugged in backwards - ouch! It is recommended that you label the connector faces with something like "parts side" or "solder side".

Step 1: Locate the CPU board

Zaxxon boardset consists of two boards (video and CPU). The CPU board is the top board and has the large heat sink in the corner near the edge connector.
ZAXXON
Zaxxon CPU board

Step 2: Remove the Z80-CPU chip

Locate and remove the Z80-CPU chip on the CPU board. Use the images below to assist in locating it. See Z80 Chip Identification for additional information. The Z80-CPU chip is a 40 pin (large) chip, located at U24. Do not get this chip confused with the 8255 sound controller located next to the Z80-CPU at U23. Remove the chip gently by using a flat head screwdriver to pry it out of its socket from each end. Be careful not to bend any of the pins. If any pins do get inadvertantly bent, you will need to straighten them out before the next step. Needle nose pliers work the best for this.
Z80 Location Z80 Removed
Zaxxon Z80-CPU location (U24)

Step 3: Insert the Z80-CPU into the daughter card

Insert the just removed Z80-CPU chip into the empty 40 pin socket on the High Score Save Kit. Make sure pin-1 is correctly oriented. Pin-1 is marked on the Z80-CPU chip usually by some type of indentation or circle molded into the plastic. The end of the chip with the marking, needs to match up with the socket on the daughter card that also has a marking on the plastic. Pin-1 is also labelled on the kit pcb with a "1".
Pin-1 Identification
Click images for a larger view
Z80
Z80 CPU Chip 		HS2
High Score Daughter Card 		HS2
Pin-1 Identification

Step 5: Insert the daughter card into the CPU board

Insert the daughter card back into the Z80-CPU socket on the CPU board where the Z80-CPU chip was originally removed from. Again, make sure pin-1 of the Z80/daughter card is oriented to correctly match pin-1 on the CPU board. Use the photos as a guide.

The header on the daughter board has pins that are more heavy duty than the original Z80-CPU pins, thus you will need to press very firmly to get the daughter card to be fully inserted into the original Z80-CPU socket.

HS kit Installed
Zaxxon with HS kit installed

Step 6: Double check your work

Review the steps and double check that Z80-CPU is properly installed into the daughter card with no bent pins and that it is correctly oriented for pin-1. (Pin-1 should be on the edge closest to the edge of the PCB). Also check that the daughter card is also installed snug into the Z80-CPU socket at U24 with pin-1 matched up.

Step 7: Powerup and game and enjoy!

Reinstall your board into the cabinet if necessary, and then powerup your game.

If the game does not come up, turn power off immediately, double check your work, and read over the trouble shooting section.