VA0 Dreamcast BIOS replacement- why the wires?

So for a full BIOS replacement the mmmonkey guide shows 2 wires being soldered on the chip after being installed, one between two pins on the BIOS chip and one going to a flash chip on the Dreamcast motherboard.

What's the actual purpose of those wires?

From what I understand one wire is so that you can flash the BIOS? I have a pre-flashed chip ready to go, so I wouldn't need to do that. Which wire is that, and what's the other one for?

Can I omit one or both of the wires on an install?

 

You need both wires. The 2 pins on thr new chip require connecting to the correct place. Leaving either disconnected will leave them in an undefined state and it won't work properly or at all.

The flashing one you could connect to 5v, which means you can never write to it. But you still need a wire regardless.

 

The wires are to tether the chip down. Prolonged use causes a build up of heat and helium within the chip which melts the solder and causes the chip to float from its contacts. Obviously!

 

That's not correct. It's to pull the /reset signal high, so the chip isn't in reset constantly. Pin 23 is 5v, pin 1 is /reset.

Pin 44 is /we (write enable)

The / or # on a signal name denotes it is active low (I.e. Connected to ground). So that reset isn't enabled, it's connected high.

You have to leave the pins in a defined state, so high or low (connected to 5v or ground respectively) connected to nothing is a 3rd state (floating) and would lead to random behaviour at best.

 

Okay, makes perfect sense, pull /reset and /we high so reset and write modes are both disabled. Thank you for the clarification!

One last question about pinout- for the VA0 guide mmmonkey has pins 23 and 44 bridged on the chip, with pin 1 connected to pin 7 on the flash chip. Does this mean for a VA0 the pinout is-
1- /WE
23- VCC
44- /RESET

As opposed to a VA1/2 having pins 1 and 44 swapped?

 

Va0 bios is pin 1 is /we. Pin 44 is /wp (write protect).

No reset on va0 chip.