Mmmm...
l'A2000 dovrebbe partire e funzionare anche col semplice 68000 , con le ROM 3.1.
Cit.:
Kickstart ROM Installation Instructions
for Amiga A500/2000
WARNING: Use anti-static precautions while handling and installing integrated circuit chips.
I) A500 SYSTEMS - INSTALLING THE KICKSTART ROM.
1. Place the A500 CPU 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 or 315093-02.
7. Note the orientation of the old operating system ROM, then remove it from the socket.
8. IMPORTANT NOTE: 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 2.04 ROM IC must have pin 1 jumpered to pin 31. This connects A17 (pin 1 on the ROM chip) to A17 (pin 31 from PCB). Align the jumpered 2.04 ROM with socket U6, and press firmly into place. Check for bent pins.
2> For Rev 6A and above, cut or remove any jumpers from the top of the chip. Align the 2.04 ROM with socket U6 and press firmly down into place. Check for bent pins.
9. 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.
II) A2000 SYSTEMS - INSTALLING THE KICKSTART ROM
1. Remove the top cover. One (1) screw on the back and two (2) on each side secure the top cover to the Main Assembly. With the front of the computer facing you, grasp the sides of the top case and carefully slide it towards you and up.
2. IMPORTANT NOTE: If the system includes an A2620 or A2630 Accelerator Board, an upgrade of the board's ROM chips may be required. For A2620, the ROM chips at position U4 and U5 must be revision -06 or higher.For A2630, the ROM chips at position U102 and U103 must be revision -06 or higher.You can check the revision without opening the case; at the processor selection screen press SHIFT-M to enter the A26x0 monitor. From the monitor use the "version" command. The ROM chips are ok if a date of 01/15/91 or later is displayed. If the ROM chips are old, then remove the accelerator board from the Amiga Coprocessor slot. For A2620, locate and remove the chips at positions U4 and U5. Location U4 is updated with the Low ROM, P/N# 390282-06 or 390282-07, location U5 is updated with the High ROM, P/N# 390283-06 or 390283-07. For A2630, locate and remove the chips at positions U102 and U103. Location U102 is updated with the Low ROM, P/N# 390282-06 or 390282-07, location U103 is updated with the High ROM, P/N# 390283-06 or 390283-07. Align the ROM IC's with the sockets and press firmly into place. Re-insert the board and test the system before proceeding with the Kickstart ROM installation.
3. Remove the seven (7) screws that secure the power supply and drive assembly to the base. Next, remove cables from the power supply sub-chassis, and carefully lift it out of the way.
4. Locate the operating system ROM (see below). The old ROM should be marked 315093-01 or 315093-02. Note the orientation of the old ROM, then remove it. IMPORTANT NOTE: Installation for the 2.04 Kickstart ROM differs depending on the PCB revision:
1> Newer A2000 motherboards are marked "B2000-CR" in the lower-left corner. The Operating System ROM, U500, is located just to the right of the 68000 and below Fat Agnus. Pin 1 faces rear. For Rev 4 and above, cut or remove any jumpers from the top of the 2.04 ROM chip. For Rev 3 boards, the 2.04 ROM I must have pin 1 jumpered to Pin 31.
2> Older machines are marked on the left side with the "(c) 1986 COMMODORE", "AMIGA 2000" and "MADE IN GERMANY (BSW)". The Operating System ROM, U2, is located just to the right of the 68000. Pin 1 faces forward. For these boards, the 2.04 ROM IC must have pin 1 jumpered to pin 31. This connects A17 (pin 1 on the ROM chip) to A17 (pin 31 from PCB). Align the 2.04 ROM with the socket and press firmly into place. Check for bent pins.
5. Installation is now complete. It is advisable to test the system after reassembling the sub-chassis and drives, but before replacing the top case.
Ti "bruci" un po' di RAM, però la macchina deve funzionare; funzionano pure gli A500.