There is no "of course" here The question ( I guess) is about the *ramdisk* use the wasted RAM, not the OS itself. Gavotte can do that in x86 NT systems even non server ones w/o PAE patch. So in theory nothing prevents to write a ramdisk that uses the wole ram even in 9x systems, its just that (afaik) nobody bothered to do that. In win 9x days 8GB of RAM was science fiction, and even a 8GB HDD was a top end one, in that scenario a 5GB ramdisk was just pointless. (it's still pointless today aside the academical question)
With grub4dos you can even boot a whole Win10 install entirely from RAM (assuming you have enough of it), booting W98 from it is a joke. Say 1GB is 1/8 of the RAM available in a today's average PC, but it's also more than 2X the size of the HDD spinning in my first "IBM compatible" PC bought in '95
Still having a 50MB HDD (Quantum) somewhere around here... They started at 5MB or even lower capacity, but huge sizes.
Yeah, I touched probably the first Mac arrived in my country (we had to buy a bulky 220/110V transformer to power it. It was labeled 117V max) and it came with a 5GB external HDD, that cost almost the same as the mac itself. More recently we got a huge (as physical size) unit, driven by a motor that you usually see in washing machines and a v shaped belt, the same kind of what you see in cars to move the alternator and the AC pump... It was likely something from 1970s, that stored data measured in kilobytes...
Care to elaborate more? Are you aware of the requirements? You need a VHD, not VHDX and that VHD must be fixed sized, or a raw img file. That file must be not fragmented (use wcontig.exe to check/defragment)
According to the maintainers of grub4dos, it is achievable; Say Win98 has a realmode mapper。 Win98 can identify non--top disks; XP is installed with SVBus driver, which can identify large --top disks; As an FD, the large market cannot work, it must be HD. Here are my test results
Dos and Win9x hasv never had the requirement of a proper driver to boot. (in that sense the Win NT family was a huge step back) In the worst case Win9x boots using whats provided by the bios (or a bios extender). You loose the long filename support and some speed but it boots. On real machine this allowed to install the proper 32bit drivers required by Windows. A pretty common case moving an HDD to a different MB with a different IDE/SCSI controller. So it should boot on a vhd provided by grub4dos
Read what I wrote. Needs a driver to work *properly* in 32bit mode, but the bios calls are enough to boot win9x (and obviously DOS), with reduced performance, no LFN support and so on.
Now is not a matter of booting, but to make full use of excess memory and use it as a high-speed disk.
Did you try out SRDisk (ReSizable RAMDisk) already? I think I did read about it once at mdgx.com/dos.htm, it is still mentioned there and the website is updated. There I read the prog can create a RAM drive up to available RAM of the system. Might be what you wished for. Seems it now is also part of FreeDOS distribution. You could make a boot floppy, start up FreeDOS and try to create that RAM drive there first. But a whole 8 gb is plenty for old OSs, not sure if that does work. Optionally you can try XMS/EMS RAMdisk mentioned at mdgx. This one is good for 2 gb max. So you could split - set e.g. 1gb for Win 98, 1gb for a RAM drive. That should probably work with a patched Win 98. Maybe also 1 gb for Win and 2 gb for the RAM drive. I have not used RAM drives in ages. Cannot be of help on how to run them. Perhaps a specialised DOS resource (forum) can assist. Edit: I cannot post any links here, great. Find the info by copy-pasting, serve yourself. Good luck.
i do not understand the problem; afaik w 98 comes with a decent underlaying m$ dos..including ramdrv.sys. you can use it up to the dos memory limit.. if you try to access memory beyond that point you will be treated to a BSOD..