A500 - Installing the 3.1 Kickstart ROM:
1. Place the A500 unit upside down on a flat surface.
2. Use a #10 Torx driver to remove the six (6) case screws.
3. Turn the unit right side up. Remove the top cover by grasping at the rear corners and lifting up.
4. Note the orientation of the keyboard wires, then remove the keyboard assembly by grasping the keyboard cable harness and gently pulling straight up. If there is a ground strap attached to the keyboard, detach it. Set the keyboard assembly aside.
5. Use needlenose pliers or a similar tool to straighten the four tabs which secure the top shield. Remove two (2) screws at the front of the PCB and two (2) on the left side of the PCB. Now remove top shield by lifting straight up. Set the shield aside.
6. The main printed circuit board is now in full view, except for the portion covered by the floppy disk drive. The operating system ROM IC is located at position U6, just to the right of the 68000 CPU chip. The old ROM chip should be marked 315093-01, -02 or, if your system is already upgraded, V2.04 (37.175).
7. Note the orientation of the old operating system ROM, then remove it from the socket.
8. IMPORTANT: There are several different versions of the A500 PCB: Rev 3, Rev 5, Rev 6A and Rev 7 (The revision number is printed on the top of the main board in the front right corner). Installation differs depending on the PCB revision:
1> For Rev 3 and Rev 5 boards, the ROM socket must have pin 1 connected to pin 31 and the ROM IC must have connected pin 21 to bent-up pin 31.
2> For Rev 6A and above, the ROM must not have any connection.
9. Align the 3.1 ROM with socket U6, and press firmly into place. Be cautious not to bend pins. ROM installation is now complete. It is advisable to re-assemble the keyboard and test the system prior to fully re-assembling the shield and top case.
(C) Copyright Village Tronic Marketing GmbH, Sarstedt, 25.08.1994
