First post, by Tmp2k
I have an Olivetti PCS/44, luckily it's got the original HDD and backup floppies. The backup battery had died so it wouldn't recognise the HDD to boot DOS. However, I did notice that when I went into BIOS (CMOS config) the HDD burst into life and started chuntering whenever I changed menus etc.
I soldered a modern battery holder on the mobo and after some experimenting, I found that setting "Hard Drive 1" to "High Capacity" allowed it to boot into DOS. The harddrive setting can be either "Standard" "High Capacity" or "None Standard" the latter allows you to manually enter CHS settings.
I've also have a "User Diskette" which is basically an MS-DOS boot disk with all the BIOS programs on it. You can boot from this disk and it has the same result as entering BIOS setup.
So here's the thing... I've put the HDD in another machine and it only reports 1 partition, I can't find the BIOS programs on it anywhere. I've also reinstalled DOS/Windows and formatted and it's not affected it. But if I don't plug that HDD into the machine, I cannot get it to enter bios setup, unless I boot from the User Diskette. Entering BIOS from the HDD does not involve booting, you press Ctrl+Alt+U and it jumps into BIOS, whereas the User Diskette is like a regular DOS boot disk. So it's like there's a copy of the User Diskette hidden on the HDD somewhere. Also it still goes into BIOS even if the HDD isn't configured correctly and the machine can't boot to DOS.
I've tried swapping the HDD and even when manually entering the CHS setting in BIOS the machine just doesn't seem to like any of the other HDDs. I'm also worried that when I swap out the HDD I'll lose the ability to enter BIOS without the User Diskette, and then what happens if the Diskette fails 😖 (I know I can make a copy etc) But I'd rather not have to use a floppy disk just to get into BIOS.
I've now started getting the occasional HDD related error so I'm worried the current HDD is on it's way out anyway.
Does anyone have any experience with this kind of BIOS system and actually knows what's doing on here? How can I swap out my HDD and keep the ability to run the BIOS config without using a boot floppy?