=====A2000 Motherboard Revisions=====

^Revision Number^Board Change^
|3.9|first 2 layer board, dealer demo only; 256KBx1 memory chips|
|4.0|last 4 layer board, has German part number|
|4.1|video fix, first 2 layer board released to consumers|
|4.2|fix for HITEK type keyboard, by removing two capacitors (the first character typed on the HITEK keyboard was lost)|
|4.3|new Gary (MOS) chip used, pull-up resistors added to support it|
|4.4|production improvements (previous modifications now included in layout), cost-reduction|
|4.5|pull-up on U605 (74ALS245) to support certain accelerator cards with the Signetics buffer chip; KS 1.3 ROM  as the new default|
|5|all brown boards, all from Germany, falls into the 'Holy Grail' territory; if you see one of these buy it at any price;  supposed to be a 4.5 with the 256KBx4 memory layout of a rev 6 board|
|6.0|new layout for 1 meg RAM chips; all RAM now CHIP memory|
|6.1|fix to clean up RAM-retention by adding a reset IC (RAM-retention occasionally caused a guru on power-up though the system would start normally if the left mouse button was pressed); Agnus 8372 (1MB) used|
|6.2|fix to get certain expansion boards to work correctly with 256Kx4 DRAMs and Agnus 8372|
|6.3| KS 2.04 ROM, Agnus 8375, and SuperDenise 8373 as the new default|

Check out [[http://w8.ca/technical/a-2000.shtml]] for some more details.