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.
Last modified: le 2023/09/12 19:25