Simple Question

I have a BIOS chip from a computer. Or let's say I have a BIOS chip or microprocessor from any device. How can I "read" it? Specifically, let's say that I have a BIOS chip from an old computer. I remove the chip and actually want to alter the menu items that come up on it. How would you do this? Is there a device that, much like the STAMP kit, allows you to interface and program the chip?

Reply to
nc
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1) Google the part number off the chip.

2) if it is a BIOS chip, then the code in the chip is x86 code, if it is _not_ a BIOS chip, you will need to find the microprocessor the code was written for.

3) the chip located in step 1 will tell you if there are programmers available for the chip concerned.

3a) if the chip concerned does _not_ have a programmmer available, stop.

3b) if the chip concerned does have a programmer, buy the programmer.

4) locate a dis-assembler for the processor in step 2.

5) read the chip with programmer in step 1 to a intel hex file and submit the file to dis-assembler in step 2.

6) read and re-read the dis-assember listing from step 5 till you understand the code to be able to modify it at the binary level.

If step 6 stops you, give up now, YOU can't do it.

good luck, you going to need it.

donald

PS: this is a simple question only if you don't know how to do it.

Reply to
Donald

Somewhere between Step-3A and Step-3B, you really should insert a basic understanding or acceptance that the chip itself may be LOCKED, so that its contents cannot be read by prying eyes.

A great many chips have this capability. On some, you can get around these protections using elaborate schemes and special tools, emulators, etc..., but not very often.

In other words, you might ID the chip, find and purchase a proper programmer, and only then find out that the chip is locked anyway - so the programmer won't read it.

Just trying to save you money and/or aggrevation.

required skills & experience anyway, so there would definitely be a learning curve involved. But probably not that steep.

Good luck.

-mpm

Reply to
mpm

it appears you may not have all the

This is great information guys! Thanks! This is one of those things that I don't have the skills for, but was always interested about learning. But everyone I ever asked looked at me as if I was a complete geek. Where did you guys start out with all this kind of stuff? I don't mind going slow. I just want to learn and enjoy the process.

Reply to
nc

question, it appears you may not have all the

First, you've got to be an actual geek. You can find out by sniffing under your arms after a workout. Gotcha! Geeks don't work out. If it smells bad anyway, you're also disqualified because geeks can only smell oily substances, which they crave for both the high calorie content and for lubrication.

But don't give up. If others think you're a geek, you can scrape by, but you'll never quite fit into geek society, which is usually known as solitude.

For reading material, I recommend the following:

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-- Joe

Reply to
J.A. Legris

mpm wrote:

nc wrote:

formatting link
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't.know.which.chip.to.use+*-must-have-for-beginners+*-*-*-*-glance-*+expound+*-*-*-*-Myke's-opinions+readable+*-*-*-inclusion-of-UMPS+without-*-*-*-*-overkill+*-AVR+*-UMPS-Tutorial-isn't-quite-right&strip=1

BTW, it's not necessary (indeed, it's POOR FORM) to blockquote the previous 3 posts *in their entirety* without cause. Trim out what doesn't relate DIRECTLY to your response.

Meaningful Subject: lines are a good idea as well.

Reply to
JeffM

If it's a BIOS chip there maybe software on the board manufacturer's website to re-write it while it's in-place.

Bye. Jasen

Reply to
Jasen Betts

On 08 Jul 2007, you wrote in sci.electronics.design:

On a PC at least, the BIOS is often in a common Flash ROM, EPROM, or an OTP oe Mask ROM chip, which can be read, and often written by software (in the case of a Flash ROM.)

Other systems may have the code flashed or, burnt, or masked onto the system chip, which may not even be readable.

As for altering the contents of the chip, it depends.

Contents may be encrypted, compressed, and/or checksum protected.

Most standalonde ROM type chips need a programmer to read/write them (assuming you have a writeable chip). Some varieties called LPC can be read/written with a simple interface.

Reply to
Gary Tait

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