3.1 ROM upgrade

[spaceman88]

I bought a 3.1 ROM on EBay for my A500 (Rev. 5, 1 meg chip RAM). My 1.3 chip has 40 pins the new one has 42, I THINK the seller says to leave pins 1 and 42 disconnected in this case (I say "think" because I emailed him twice with no results). Of course it doesn't work. Is there something else I'm supposed to do? Thanks.

[spaceman88]

That is a picture of an a600 motherboard, they either have 40 pin or 42 pin sockets. I can't tell from that angle as there are too many optical illusions going on with the lighting and the angle. Here is a less insane picture http://www.bigbookofamigahardware.com/bboah/media/download_photos/a600mb_rev15_2.jpg

This is a rev 5 a500 http://www.bigbookofamigahardware.com/bboah/media/download_photos/a500mb_rev5_3.jpg, which only has a 40 pin socket (the a500+ has a 42 pin socket).

Normally you would only use 42 pin sockets for 1mb kickstart roms (i.e. 3.9 etc), 2 extra pins means there is up to 4 times the capacity. If he programmed each part of the rom with the same contents then you may get away with leaving the extra pins floating (1mb rom would need two copies, 2mb rom would need 4 copies). I'd personally bend the extra pins up and solder a wire to ground to avoid any doubt.

I believe the extra pins that don't go into the socket are the ones at the end with the notch, because when you go the other way and put a 40 pin rom into a 42 pin socket then these are the pins that are empty.

That's the way I installed it, with pins 1 & 42 (by the notch) hanging over the end. It's supposed to be a regular 3.1 (licensed from Cloanto). I didn't think of AmigaKit at the time!
Mike- Yes socket 40 pins- 1.3 ROM 40 pins - 3.1 ROM 42 pins

[spaceman88]

You say Cloanto.  Is it a standard 3.1 ROM or the special Cloanto "3.X" ROM?  If it's a 3.X, you may have it installed properly, but have myriad completely unrelated problems because of the changes they made in it.  

What color is your screen when you try to boot with the ROM installed?  Any clicks from the floppy drive, does the power light go bright or stay dim, stuff like that?

This is the EBay link... http://www.ebay.ca/itm/152218201029?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT  
I'm using a Dell monitor which takes a few seconds to show a screen then goes black, but I think I saw a pink flash before it went black. No floppy click, not sure about the light. If I put 1.3 back in the 1.3 "hand" comes back.

Amiwest- Very interesting link, would have been nice for the seller to share this info. Would be nice for him to answer my Emails!!

[spaceman88]

Just a quick update... After 3 emails to the seller, no response. Great customer service! I didn't want to solder the jumpers on the chip in case it didn't work and the seller claims I "damaged" it. I took apart my A2500 which has 3.1 and found an Escom 40 pin ROM chip, I removed it and put the 42 pin EBay chip in the 2500 and it worked. So I kept the Escom chip for the 500 and ordered a socket so I could do the soldering on it instead of the ROM chip in case I swap things around again :-). Thanks to everyone for the links and info about jumpers.