The Mother Board

Motherboards.org forums. Free tech support, motherboard ID, and more.
It is currently Tue Sep 18, 2018 8:05 pm

All times are UTC - 8 hours




Post new topic Reply to topic  [ 5 posts ] 
Author Message
PostPosted: Sat Jan 24, 2009 2:50 pm 
Offline
Black Belt 2nd Degree
Black Belt 2nd Degree

Joined: Wed Feb 26, 2003 11:34 am
Posts: 2161
Location: Newport, Rhode Island USA
Two 256k Chips: One is sectored as 4X64k and the other is structured as 3X64k, 1X32k, 2X8k, 1X16k. Now, the question is: can these two chips be flashed by the same bin and be used interchangeably?

Thanks,

Miki.

_________________
Help humanity .....join the
Motherboards.org
folding team! 33258


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sat Jan 24, 2009 3:20 pm 
Offline
Mobo-fu Master
Mobo-fu Master

Joined: Wed Nov 12, 2003 11:57 am
Posts: 20858
Location: 07438
If the two chips are the older DIPP type, there would be one "high" and one "low" entity. Or could be marked "odd" and "even". One chip had the "odd" bit count 1, 3, 5, 7, etc. while the other chip had the "even" bit count 0, 2 ,4 ,6, etc. memory design.
Normally in a 28-pin package. They must be in their respective sockets. They were from the days when memory structure was large, and there was room for only one 'bank' of pages.. either odd or even. That series came to an end, in the latter years of the '386' processor. Today's BIOS chips are about 1/3 the size of one older DIPP, and can have over 2 Mb of hi/lo memory bit structure.
If there is a foil label on the tops of the chips covering a small window, they cannot be flashed with a disk. An 'eraser' using a UV lamp would be needed, then a reprogramming 'burner' would write the new data. The foil label is peeled away to expose a tiny tinted window above the memory structure. Commonly known as EPROM chips.
You could sometimes have success with replacing the BIOS chips with newer models, as long as it was the same "family".. either AMI or Award/Phoenix.

_________________
F@H.. to solve mankind's maladies.. in our lifetimes!


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sat Jan 24, 2009 7:33 pm 
Offline
Black Belt 2nd Degree
Black Belt 2nd Degree

Joined: Wed Feb 26, 2003 11:34 am
Posts: 2161
Location: Newport, Rhode Island USA
Karl,

Is there any similarity between EPROM formatting and hdd formatting? If so, like any file can be written to a FAT or NTFS drive, it might be possible to flash two differently formatted chips with the same bios file.

_________________
Help humanity .....join the
Motherboards.org
folding team! 33258


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Jan 25, 2009 3:15 am 
Offline
Mobo-fu Master
Mobo-fu Master

Joined: Sun May 06, 2001 12:01 am
Posts: 37463
Location: Netherlands
If they are pin-compatible and the flash program does recognize what it is, I don't see why not.

_________________
We hate rut, but we fear change.
********************************
System error, strike any user to continue...


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Jan 25, 2009 1:41 pm 
Offline
Mobo-fu Master
Mobo-fu Master

Joined: Wed Nov 12, 2003 11:57 am
Posts: 20858
Location: 07438
A hard drive will write data to the next available sector for whatever length the string file is. But with EPROM programming, you must address a specific bit register with the desired "0" or "1". The design is ROM, with specific addresses.. and if the wrong info is in the bit register, the system won't work properly.
You would need a 'burner' deck like the one in this link, and of course the program data chart for the chip. Here is some basics on EPROM 'burning'. With those chips having small windows, you must be careful not to expose them to strong UV light sources.. or the program can be corrupted easily! They have to be treated like the old-fashioned glass photography plates.
The modern BIOS chips don't have that 'window' for erasure.. they are designed to allow a program input through a secondary BASIC chipset that controls the erasure and writing through an external program.. via floppy disk, most commonly. The modern BIOS setups have two memory structures.. the ROM for default setups, and the PROM for BIOS configurations according to machine usage.
I still have my 'erasing oven', but foolishly sold my programming deck. :(

_________________
F@H.. to solve mankind's maladies.. in our lifetimes!


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 8 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group