Why Can I Flash Some BIOS Chips a Clip and Others Desoldered?

[CapThatBrass]

Hi,

I'm trying to find if there's a logical answer or reason why some BIOS chips can be flashed/programmed whilst still attached to the board (CMOS battery and main battery disconnected) via a clip/pogo probe, and other chips require them to be desoldered and mounted onto some other platform, whether it be a specific PCB or a clamping mechanism. This is regarding laptop and desktop computers.

Any explanations would be handy to know.

Cheers.

[eccerr0r]

Re: Why Can I Flash Some BIOS Chips a Clip and Others Desoldered?

completely depends on the chip. Some are designed to be in-circuit programmed, others are simply not...

The chips that aren't designed to be in-circuit programmed may however be in a circuit that allows programming, and these however depend on the circuit for programming and thus require special software that knows about the circuit.

This is not specific to computers but any device that uses a memory device, whether it's a microcontroller or general purpose computer.

[stj]

Re: Why Can I Flash Some BIOS Chips a Clip and Others Desoldered?

it's caused by the other circuity on the board.

[CapThatBrass]

Re: Why Can I Flash Some BIOS Chips a Clip and Others Desoldered?

Thanks for the explanation guys.