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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: christine5 on May 31, 2005, 10:22:54 PM

Title: Kickstart 3.1 ROM on A500 revision 5 board
Post by: christine5 on May 31, 2005, 10:22:54 PM

I have a revision 5 A500 motherboard which I want to upgrade to a kickstart 3.1 ROM.

Does anyone know what jumpers need to be added or pins bent out etc for this conversion?

I seem to be getting different opinions on this???

TIA

Christine

Title: Re: Kickstart 3.1 ROM on A500 revision 5 board
Post by: Bandaid on May 31, 2005, 11:10:24 PM

Christine5,

On revision 5 A500 models you must make sure that pins 1 and 31 on the Kickstart 2.x or 3.x ROM are connected with a jumper wire.

Revision 6A and 7 A500 models should have the jumper removed (i.e., do not connect pins 1 and 31 on the Kickstart ROM).

On ALL A500 models (Rev 5, 6A, 7) when using Kickstart 1.x ROMs you do not use ANY jumper because 1.x ROMs are 128kbit X 16 ROMs (i.e., 256Kbytes).

The later motherboard revisions (6A, 7) have pin 1 redefined to be the A18 address line.  This enables the use of 512KByte ROMs (256kbit x 16) without jumpering.

Hope that helps.

Title: Re: Kickstart 3.1 ROM on A500 revision 5 board
Post by: Doobrey on May 31, 2005, 11:22:11 PM

There's a short description at http://www.nyx.net/~rdavis/AmigaHints2.html#v31rom (http://www.nyx.net/~rdavis/AmigaHints2.html#v31rom)

Pretty much as the previous post described, but it also mentions bending pin #31 so it doesn't go in the socket.

I think there's more information in the dc-kf500 archive on aminet about this too.