Stupid question about Fat Agnus

[Ilwrath]

Do you have to replace Agnus with another version to do the 1mb alteration?

Depends on which Agnus you have.  As I understand it, you need at least an 8372A.  I think some A500s with 6a motherboards were sold stock with that chip and just need a little jumper modification to enable 1MB, while others need the chip and the jumper.  As far as I know, no Rev 5 or earlier A500s had the 1MB Agnus stock.

[Ilwrath]

Then you had an A500 with 2 Meg Chip!

Yeah, I've seen A500's with 2MB chip.  I thought there was a custom 68000 socket board that needed to be installed along with the 8372B, though.  Maybe that just added the extra RAM sockets if your A500 didn't have them, though.

My original A500 was a 6a with the 8372A.  I modified it up to 1MB chip and then had 4MB fast on my DataFlyer HD/RAM card.  Assembled, the whole unit was so wide it barely fit on my desk.  :lol:

[Ilwrath]

Is there a plain 8372?  If so, I imagine it's just a bugged version of the 8372A.

8370 is NTSC only 512k Agnus.
8371 is PAL only 512k Agnus.
8372A is NTSC/PAL switchable 1MB Agnus (will work as a drop-in replacement for an 8370/8371.)
8372B is NTSC/PAL switchable 2MB Agnus.
8375 is another NTSC/PAL switchable 2MB Agnus.