here in india, i have not been able to procure a bios savior or similar product. So i set upon the task of making one.
i procured the following parts
1 New Bios chip(similar to one in mobo)
The original Bios from mobo
2 32-Pin PLCC Sockets
1 32-Pin PLCC Adaptor
32-terminal switch
now it would be soldering the wire
Adaptor
|
Switch
| |
PLCC-1 PLCC-2
Bios Bios
Problem is wiring the 32-lines is a elaborate task,
I suspect there may be a simple solution
How is bios savior doing the wiring ?
wiring dual bios
32-terminal switch?! how about driving CE# (Chip Enable) to a high level with a pull-up resistor and thus 'deselecting' one of the chips? which leaves us with a 3-terminal switch to GND and much less wirework (piggyback mounting the chips).
Thanks for replying cp
I greatly appreciate your guidance
I cannot find the CE#(Chip Enable) in the documentation of the Bios Chip, Plz. take a look at page 9
http://www.sst.com/downloads/datasheet/S71161.pdf
NOTE - On my KOB-815e-FSX mobo it is SST 49LF002A /3.3V but the docs available are for SST 49LF008A /3.3V, i guess both are the same except for size 2MB Vs 8MB
I did find OE#(Output Enable) and WE#(Write Enable) pins but the docs say that they are not available in FWH mode
Then there remains ID[3:0](Identification Inputs), docs say these allow multiple parts to be attached on same bus
Hardware details
BIOS Date: 02/23/01
BIOS Type: Award Modular BIOS v6.00PG
BIOS ID: 02/23/2001-KOB-815e-FSX-KOB815eC-00
OEM Sign-On: KOB 815e FSX 02/23/2001
Chipset: Intel 1130 rev 2
Superio: ITE 8712F rev 4 found at port 2Eh
CPU Type: PENTIUM III
Flash Type: SST 49LF002A /3.3V
(SST Web Page)
http://www.sst.com/products.xhtml/seria ... ST49LF008A
For the pull-up resistor would a 10k ohms be sufficient ?
I greatly appreciate your guidance
I cannot find the CE#(Chip Enable) in the documentation of the Bios Chip, Plz. take a look at page 9
http://www.sst.com/downloads/datasheet/S71161.pdf
NOTE - On my KOB-815e-FSX mobo it is SST 49LF002A /3.3V but the docs available are for SST 49LF008A /3.3V, i guess both are the same except for size 2MB Vs 8MB
I did find OE#(Output Enable) and WE#(Write Enable) pins but the docs say that they are not available in FWH mode
Then there remains ID[3:0](Identification Inputs), docs say these allow multiple parts to be attached on same bus
Hardware details
BIOS Date: 02/23/01
BIOS Type: Award Modular BIOS v6.00PG
BIOS ID: 02/23/2001-KOB-815e-FSX-KOB815eC-00
OEM Sign-On: KOB 815e FSX 02/23/2001
Chipset: Intel 1130 rev 2
Superio: ITE 8712F rev 4 found at port 2Eh
CPU Type: PENTIUM III
Flash Type: SST 49LF002A /3.3V
(SST Web Page)
http://www.sst.com/products.xhtml/seria ... ST49LF008A
For the pull-up resistor would a 10k ohms be sufficient ?
okay, i see.
you might use the ID pins and swap the chips' ids around. my first guess would be: ID0 is the BIOS chip.
another approach would be to set IC->high and thus setting the chip to program mode. additionally pull up OE# to make sure the data lines are tri-stated. even if the 'real' bios is now programmed the 2nd chip's data lines are floating and electrically disconnected from the bus.
there's no general value for a pull-up/pull-down resistor but in _most_ cases 10k is a good choice. the internal pull-down resistors on the ID pins are 20k-100k (as stated in the datasheet). so in this case 10k would be the right choice.
you might use the ID pins and swap the chips' ids around. my first guess would be: ID0 is the BIOS chip.
another approach would be to set IC->high and thus setting the chip to program mode. additionally pull up OE# to make sure the data lines are tri-stated. even if the 'real' bios is now programmed the 2nd chip's data lines are floating and electrically disconnected from the bus.
there's no general value for a pull-up/pull-down resistor but in _most_ cases 10k is a good choice. the internal pull-down resistors on the ID pins are 20k-100k (as stated in the datasheet). so in this case 10k would be the right choice.