dos or not to dos
October 19, 2019 at 7:39 pm #37553Participantjohnbarry@johnbarry
When you first start up a computer (before Windows loads) to enter the bios/boot from CD/DVD etc
ie when you load True Image recovery CD – Windows ME startup CD and you get the small white text.When installing a fresh copy of Windows you get a message Press Any Key To Boot From CD.
All this is before Windows What is it called?
I used to call background loading as loading into Dos.
October 19, 2019 at 7:55 pm #37556
The BIOS messages are just that, they are not an “operating system” as such. Your interaction is limited to confirmatory key presses or selecting menu options.
After that it’s still Windows but it’s from the command line not the graphical user interface.
DOS is a totally different operating system, even though some commands still have the same name.October 19, 2019 at 8:09 pm #37559
I get the picture.
JohnOctober 19, 2019 at 9:01 pm #37563
John I thought you meant something like this. This holds for most PCs though there seems to be a move to eliminate the cmos battery bit. Apples are different and use something called nvram.October 19, 2019 at 9:33 pm #37564
I don’t think the CMOS battery is going anywhere just yet. The trouble with NVRAM is that it can only be written in large blocks and it must be erased before it can be rewritten, that is why it is accessed as a disk with a disk controller in an SSD. That sort of setup is not really suited to the kind of data held in CMOS which needs to be accessed like normal ram.October 19, 2019 at 10:41 pm #37568
I did wonder about the Mac though so the answer is above. Battery as usual 😁October 20, 2019 at 8:39 am #37577
Thanks Ed & Graham
My Lenovo doesn’t see the USB keyboard at first boot (until Windows comes in. It does see a PS2 Keyboard.
So when you first install Windows it says press any key to continue, if you only have a USB keyboard in you can’t press any key (hence the PS2 keyboard) I was after a word like Dos to explain, ie a USB keyboard isn’t seen in Dos for people to understand in a sale description.
JohnOctober 20, 2019 at 8:45 am #37579
There are a few motherboards like that, I believe it’s down to the BIOS. Not had the issue with more recent motherboards though.
You’d have thought it would have been sorted years ago but you still see PS2 ports on new mobos. I struggle to understand what legacy kit keeps it going. Keyboards it isn’t.October 20, 2019 at 10:55 am #37583
I suppose you have enabled legacy keyboard support in the BIOS? The setting is to make a USB keyboards work with a legacy OS like DOS and also self boot utilities based on DOS. It has nothing to do with PS/2 keyboards.
The setting is enabled automatically during system boot and in BIOS setup but it is then disabled once an OS loads unless the legacy setting is set to ON.October 20, 2019 at 11:06 am #37584
Until recently I would have said that a PS/2 keyboard will always work but that is now not true with W10.
If you instal W10 without a PS/2 keyboard connected then it does not instal the PS/2 driver and it is a devil of a job to instal it later. Because PS/2 keyboards are not plug and play devices refreshing your device list will not detect them.October 20, 2019 at 1:07 pm #37590
Thanks Dave n Graham
This will only see PS2 on first install to selet any key to coninue. I had this on MM with my last Lenovo, Lenovo even changed the motherboard. What ever I select in the bios (it’s getting in) doesn’t help. It is only when you boot CD/DVD fist time.
JohnOctober 20, 2019 at 3:32 pm #37591
As a matter of interest the only essential function on a motherboard that requires a battery is the CMOS clock. Today all the other bits and pieces are capable of being self configurable and have their settings in either read only memory (NVRAM) or programmable read only memory (PRAM). Even the clock battery isn’t really required. The Pi and most IoT devices do not have one, but if they can connect to the Internet on booting that hardly matters.
October 20, 2019 at 6:55 pm #37595
- This reply was modified 7 months, 2 weeks ago by Ed P.
The stuff that is held in CMOS are mostly things that YOU configure Ed. I like my base clock to be 160 instead of 133, my disk interface to be AHCI not IDE, etc, etc.
PCI devices do not need to store their configuration data in NVRAM, although most will have a default in EEPROM, because they are reprogrammed at every boot. The ACPM component of the BIOS/UEFI will have first crack at it in case you want to load an OS like DOS but if you load a more modern OS then its plug and play manager will do it all again to its liking 😁
Happens every boot so setting on the card are only stored in RAM and vanish when the power goes off.October 20, 2019 at 8:54 pm #37600
There is no TECHNICAL reason to use CMOS for things that you change , they could equally well be in a text file read in by the boot routine. Most IoT devices work in that way. Obviously PRAM and PROM could also be used in a similar way.
CMOS is currently used because it is off the shelf, cheap and a battery costs just a few pennies. It is currently much less costly than setting up PROM or PRAM. It is also a bit more secure than a text file!October 20, 2019 at 10:09 pm #37607
You COULD use a config file on disk but you would finally break the backwards compatible PC standard. Even newest PC can be setup to boot from a DOS floppy if you try hard enough.
You could also design a setup program that read all the config data from a flash ram chip into a ram buffer, let you change it and then erased the flash before writing the data back again as a block.
You could, but it is much more of a faff and you would again break the PC standard because DOS changes config settings just by writing to memory addresses.October 20, 2019 at 10:29 pm #37608
No one has yet been brave enough to stand up and say that if you buy this PC it WILL NOT boot into DOS 😁October 25, 2019 at 8:40 am #37756
If you instal W10 without a PS/2 keyboard connected then it does not instal the PS/2 driver and it is a devil of a job to instal it later. Because PS/2 keyboards are not plug and play devices refreshing your device list will not detect them.
I’ve just found out this isn’t true. I built a new PC for a customer and no PS2 keyboard in sight. Got to site, they have an old Dell mechanical keyboard that’s PS2, thought about this post and thought sh1t.
Plugged it in, it just worked. Instantly.October 25, 2019 at 9:28 am #37757
I just looked it up and you are right ! It was an error MS introduced but they fixed it two builds ago 😀October 25, 2019 at 9:35 am #37758
But if you do find yourself with a Windows install that doesn’t have the PS/2 driver installed then the advice seems to be to reinstall Windows because an update won’t fix it 🤔October 25, 2019 at 10:18 am #37759
It was a a fundimental problem and I don’t think it was actually an error. If the faulty version of Windows didn’t detect ANY legacy devices during an install then it did not install the structure that handles pin signalled interrupts which makes things less complicated for MS. As a PS/2 keyboard is likely to be the only legacy device left on a modern PC thats what happened.October 25, 2019 at 6:26 pm #37771
My problem is well before windows, as long as it has a PS2 keyboard plugged in then I can select press any key to continue (whilst loading an OS CD/DVD on startup of a fresh install.
This problem is long running I think it was Bob Williams? whos sent me a PS2 keyboard, if it wan’t Bob (williams) then ooppss my memory is —— up again. it could have been BJM
- This reply was modified 7 months, 1 week ago by johnbarry.
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