jakethompson1 wrote on 2020-10-28, 02:30:

How did you dump the backup? The good news for troubleshooting is I'm pretty sure it is just a corrupted version of the V3.20 bi […]
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Robhalfordfan wrote on 2020-10-24, 11:25:

I thought the original backup was maybe it did get corrupted while backing up

How did you dump the backup? The good news for troubleshooting is I'm pretty sure it is just a corrupted version of the V3.20 bios you posted. The compressed original.tmp is stored in the first 0xff49 bytes; only a few bytes in that section differ:

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1$ cmp -l 4umw002.bin ORI_BIOS.ROM | awk '{ printf "%5x %2x %2x\n", $1, strtonum("0" $2), strtonum("0" $3) }'
2    1 25  0
3 2aab b1 11
4 5556 3f  0
5...

If I "repair" those bytes using a hex editor in fact it's possible to extract original.tmp from your ORI_BIOS.ROM, and it indeed has the 3.20 version inside.

This doesn't solve the mystery of why you are having trouble with cache though. You definitely cleared your CMOS with the jumper if you had one, and did "Load Power on defaults" and "Load BIOS Defaults" in setup before you started messing around? As Feipoa has in his MB-8433UUD manual there may be hidden CMOS settings you can't see that change between bios versions, and that you can only reset using the "Load defaults" settings.

There's no way you inadvertently bumped off a cache-related jumper when you were messing with the bios chip?

thank you i thought maybe a hex editor could help but i would have no idea what i would be looking at and even do - like the code part there - its all greek to me

i used the program award flash in dos before i knew it was an eprom

i cleared the cmos the using the jumper on mobo and removing the battery for 20+ mins

the only default setting in v3.20 bios that i have is load setup defaults and load bios defaults

i have try loading those defaults one at time and at same time and still doesn't want to boot with l2 cache turned on - but at least it got past updating escd unlike with v3.30 bios (latest version for this mobo) with l2 cache on

i never touch the jumper for l2 cache as that was set that way on the board when got originally got it and worked with no issues until i try to "update the bios" (deffo learned a lesson and learning new stuff with along the way as well)

is it possible to fix the ori_bios backup and if so could upload it and i will try it on eeprom (flash rom) and see it that works and fix the l2 cache and boots etc

when i try the ori_bios backup at first, turned on the pc and it beeped twice quickly and a constant long beep and nothing on screen

and try another time after overwriting v3.20 bios with the ori_bios backup without clearing the buffer and it weirdly just beeped twice quickly and floppy drive light was on like it wanted to boot from it but nothing on screen

I wouldn't mess with ORI_BIOS. It's corrupt. I'm almost certain that the 4umw002.bin bios you found is what you had originally.
Your TL-866 II can test SRAM chips, by the way. I don't think it's thorough enough to tell whether a chip is slower than advertise, but it can identify if one is dead.

jakethompson1 wrote on 2020-10-28, 17:34:

I wouldn't mess with ORI_BIOS. It's corrupt. I'm almost certain that the 4umw002.bin bios you found is what you had originally.
Your TL-866 II can test SRAM chips, by the way. I don't think it's thorough enough to tell whether a chip is slower than advertise, but it can identify if one is dead.

i didn't know that - what would the chip type be there as i have selcet the ic type before reading the chip

Robhalfordfan wrote on 2020-10-29, 18:10:

i didn't know that - what would the chip type be there as i have selcet the ic type before reading the chip

Manufacturer: "Standard SRAM", Model: "62256" (For the usual 256kBit chips, where 8 of them yield 256KByte L2 cache), at least that's how it's printed in the "supported devices list".

mkarcher wrote on 2020-10-29, 23:43:

Robhalfordfan wrote on 2020-10-29, 18:10:

i didn't know that - what would the chip type be there as i have selcet the ic type before reading the chip

Manufacturer: "Standard SRAM", Model: "62256" (For the usual 256kBit chips, where 8 of them yield 256KByte L2 cache), at least that's how it's printed in the "supported devices list".

i actually do not have that option in the software and searched for model with all and sram/nvram option it doesn't appear

Robhalfordfan wrote on 2020-10-31, 13:08:

i actually do not have that option in the software and searched for model with all and sram/nvram option it doesn't appear

There's definitely an option compatible with those chips somewhere. You can use any 256kbit chip with a compatible pinout

jakethompson1 wrote on 2020-10-31, 18:51:

Robhalfordfan wrote on 2020-10-31, 13:08:

i actually do not have that option in the software and searched for model with all and sram/nvram option it doesn't appear

There's definitely an option compatible with those chips somewhere. You can use any 256kbit chip with a compatible pinout

ok, will try at some point - giving myself a break from it for a wee bit - oh joys oh old 486 mobos 😀

i am trying look for pin compatible option on my programmer to read the cache chip and i have no idea which would be pin compatible and same memory size

the programe i am using is one that came with programmer which xgpro