This is an old revision of the document!


A2000 Motherboard Revisions

Revision NumberBoard Change
3.9first 2 layer board, dealer demo only
4.0last 4 layer board, has German part number
4.1video fix, first 2 layer board released to consumers
4.2fix for HITEK type keyboard, by removing two capacitors (the first character typed on the HITEK keyboard was lost)
4.3new Gary (MOS) chip used, pull-up resistors added to support it
4.4production improvements (previous modifications now included in layout), cost-reduction
4.5pull-up on U605 (74ALS245) to support certain accelerator cards with the Signetics buffer chip; Kickstart 1.3 ROM used
5all brown boards, all from Germany, falls into the 'Holy Grail' territory; if you see one of these buy it at any price
6.0new layout for 1 meg RAM chips
6.1fix 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 used
6.2fix to get certain expansion boards to work correctly with 256Kx4 DRAMs and Agnus 8372
Last modified: le 2023/09/12 19:05