[LinuxBIOS] Cheap self-built BIOS saviour for 8M/16M parts?

[Tom Sylla]

Carl-Daniel Hailfinger wrote:
> So you'll need:
> * 2 identical flash chips
> * intermediate switch (can be hardware)

You need to disconnect ID0 from the board to the ROMs also, bending the 
J-Lead of that pin on the bottom part up is possible, and it won't break 
if you do it only once. (boards sometimes short ID pins to ground, with 
no pulldown to defeat)

> * a way to drive RST# to GND without shorting the board
> * serious soldering skills to solder two chips to each other

It is not that difficult. Straighten out the J-Leads on the "top" PLCC. 
Stack the parts, and just keep the solder from messing up the pins on 
the bottom part, and you are fine. Thirty-two pins soldered will be 
quite strong. You'll end up with two roms stacked up, and a jumper super 
glued to the top one. If you want to make 100, you'll want to just make 
a pcb.

> Sounds nice?
> Surely there's a catch. It can't be that easy, right? Tell me!

Production lines utilize this same feature, the bed of nails controls 
the ID pins to allow automated test and programming by using 2 LPC parts 
on the same bus. It will work fine.