A10001986 wrote: ↑
Wed Oct 13, 2021 7:03 am
nonarkitten wrote: ↑
Sun Oct 10, 2021 12:35 pm
intric8 wrote: ↑
Sun Oct 10, 2021 12:06 pm
Let me ask some of the hardware gurus if any of the other A500 revisions are compatible as I don't remember.
Speaking on behalf of no gurus, the 8372ab and 8372b are the only two, 2MB options that are pin compatible that I know of.
No. The 318069-18 (PAL) and 318069-19 (NTSC), apart from pin 41, are, too. Pin 41 needs to be "connected" to gnd through a 100nF cap, and any pull up (if present) needs to be removed. On the A3000, for instance, this means "bridging" the PAL/NTSC jumper J200 with said 100nF cap, and cutting R203.
Yeah, Commodore's numbering for Agnus is all over the place. Okay, referring the list online (https://bboah.com/?action=artikel&cat=51&id=2174
... if you only want 1MB, you may use an 8372 (318069-02), 8372A (318069-029), 8375 (318069-16 or 318069-17). Basically any Fat Agnus pulled from an Amiga 500 or 2000.
... if you want 2MB, you may use an 8372AB (318069-03), 8372B (318069-03) or 8375 (318069-19). Basically any Fat Agnus pulled from an Amiga 3000 only
The more common 2MB 8375's from the 500+ and 600 (318069-10, 318069-18, 390544-01, 318069-11 or 390544-02) should work with an adaptor board similar to the DKB MegAChip or ACE2.