Amiga.org

Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: AmmoJammo on October 06, 2013, 06:46:09 AM

Title: Amiga 500, 1meg on board, fail!
Post by: AmmoJammo on October 06, 2013, 06:46:09 AM

I've just soldered an extra 512k to a rev 6a motherboard...

When I set JP2 to make it chip ram, the machine fails to boot and just flashes the power light at me.

Set JP2 so its "fast" ram, and it boots up, showing about 900k free in workbench.

Running sysinfo shows 512k chip ram.... and 506k fast.... ah...

I assume this means the ram is broken?

*sigh*

Title: Re: Amiga 500, 1meg on board, fail!
Post by: Tenacious on October 06, 2013, 07:02:36 AM

Off the cuff.  It may take more than JP2 to map the ram you added to the MB to the correct address space.

You didn't mention if you also have trap door memory installed.

Title: Re: Amiga 500, 1meg on board, fail!
Post by: AmmoJammo on October 06, 2013, 07:11:30 AM

No trap door memory, I got this memory of a bad motherboard... so its quite possible the issue was the memory...

Title: Re: Amiga 500, 1meg on board, fail!
Post by: AmmoJammo on October 06, 2013, 07:22:23 AM

I'd changed JP7A...

It seems JP7A shouldn't be changed position, it should be completely removed ;)