Need a bit of help with 512K upgrade (Rambo/Buchholz)

[Gunstar]

I finished this upgrade to my 1200XL with the Rambo XL 256k upgrade already installed, but after testing it's not working. But before I go searching for the problem, I may know what it is already, but need some verification: The upgrade instructions detail desoldering one end of a 33 ohm resister at R108 on the motherboard, this is the proper location of this resister on the 800XL, but not on the 1200XL, the instructions suggest to trace from pin-15 on the memory chips back to the proper 33 0hm resister on the 1200XL. I did this and the location I thought was right was the 33 ohm resister at R100 on the 1200XL. Can somebody who has done this 512k upgrade please verify that I'm using the right resister/location or if I'm wrong and if so, where is the correct resister location? It's the spot where pin-1 of the 74LS139/74S139 chip is connected at the pad where the 33 ohm resister lead was removed and where pin-5 (74LS139) or pin-4 (74S139) are connected to the lifted lead of the 33 ohm resister(location R108 on the 800XL).

Edited March 8, 2007 by Gunstar

[Gunstar]

Well, never mind, I figured it out, and it was just a simple problem, as they usually are; I had the location of R100 on the 1200XL right, I just lifted the wrong end of the resister and had the wires going to the pad and resistor lead crossed. My 512K XL is up and running!

[mimo]

If my 1200 ever turns up I will be wanting to do this one

[Gunstar]

I'm done upgrading this one for a little while, though I'm seriously considering and internal SIO2CF or similair type mod. And if that new graphics board for the 8-bit is ever released I'll be upgrading to that. Maybe a 65816 upgrade someday?