Timeline for Are BIOS ROMs interchangeable among different vendor's PCs?
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
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| Jun 24, 2020 at 19:47 | comment | added | abligh | @user253751 I will admit my memory of this is pretty vague. This would have been an early AT clone 286 machine in ~1986 when AMI was new (from CAS micro if anyone remembers cheap clone makers in the UK). It's possible of course there was only one generic AT compatible motherboard at the time, and hence only one AMI Bios. What I remember is getting the BIOS from someone other than the manufacturer without (I believe) specifying the motherboard. Pretty sure the original BIOS was Phoenix not Award. | |
| Jun 24, 2020 at 12:07 | comment | added | Jonathan | I vaguely remember motherboards (by MSI, late-90's?) that supported both AMI and Award BIOSs, and you could download and flash either one. Still, both the AMI and Awards were tailored to the specific motherboard versions. | |
| Jun 24, 2020 at 9:49 | comment | added | Criticizing Israel not allowed | @abligh Are you sure they didn't add their own init code to the bios? | |
| Jun 24, 2020 at 8:09 | comment | added | Justme | @JeremyP It is likely that a BIOS meant for a 286 motherboard contains opcodes that are available on the 286 but not available on a 8086. It is also very common that BIOS tests how much memory is installed, and testing how much memory is available above 1MB is not possible in real mode either. I find it unlikely that any manufacturer would waste valuable EEPROM memory space for a single unified BIOS that supports multiple CPU types, as each CPU type would need the chipset specific code as well. | |
| Jun 24, 2020 at 7:43 | comment | added | JeremyP | "Instructions for a newer CPU". Unlikely. The BIOS mainly had to operate in real mode. | |
| Jun 24, 2020 at 6:25 | comment | added | abligh | I'm not sure the answer to this is quite as much "no" as others have indicated. My hazy memory is in the early days of PC clones (I'm talking 8086, 80286), and the early days of AMI BIOS, you could (a) move from a Phoenix BIOS to an AMI BIOS, and (b) it was the same AMI BIOS that ran on most cheap clones as they all de-facto had the same chipset - or at least sufficiently compatible that AMI ran. My hazy memory also suggests that various cheap clone makers liked AMI BIOS because they ... um ... could "forget" to pay anyone for the BIOS.Once chipsets became more diverse, this changed. | |
| Jun 23, 2020 at 20:35 | comment | added | Raffzahn | @BrianH exactly. It's the worst kind of closed source possible ... hidden deep under many layers of special hardware. | |
| Jun 23, 2020 at 20:21 | comment | added | Brian H | That's basically what I was afraid of. If it was common practice in that time period to hard code very specific hardware details into the BIOS code, then any sort of BIOS maintenance is very difficult once the OEM has dropped support for the machine. Right? | |
| Jun 23, 2020 at 20:14 | history | answered | Justme | CC BY-SA 4.0 |