A500 Rev5 3.1 KS upgrade Questions

[psxphill]

is it possible to get like a Rom socket adapter thats prejumped/wired to fit in over it to go w/ a KS 3.1 Rom?  or should i keep mine @ 1.2?

An original 3.1 ROM from the 1990's will work with just a jumper between pin 1 & 31. This would be my recommendation, but cost may be an issue.

eproms need more work.

1. Bend up pin 31, solder it to pin 21 to keep it in word mode.

then to get A17 on pin 1 either

2a. build a tower with two rows of pin headers and solder a wire from pin 1 of the rom to the empty hole of pin 31. This has the disadvantage of making the rom higher, which can cause a problem for some expansions.

or

2b. solder a wire from pin1 to pin 46 of the 68000.

I wouldn't hack a revision 5 motherboard. I think the ACA500 would allow you to run kickstart 3.1 without even opening the case.

[psxphill]

Not that it's terribly helpful but a quick search on ebay shows a bunch of Rev. 6 A500 motherboards starting in the $60-$70 USD range.  With the newer board it's just "pop right in", you don't have to do any soldering or modifications.

http://amiga.resource.cx/mod/a500.html

You also get to take advantage of the higher density ram chips & newer-model Agnus.  

If you want > kickstart 1.3 and a newer agnus then I'd have thought an a500+ would be a better starting point. Back in the day I had my rev 5 tricked out with 2mb agnus plus an extra 1.5mb in the trapdoor and a home made gary tower to make it all work together with kickstart 1.3 and 3.1. But today I would just leave everything stock and just use trapdoor and maybe an expansion port accelerator + hard drive + ram.