The partition size limit is an OS thing, you did well keeping it below 2GB for FAT16.
However there is also the BIOS hard disk limit, which in your case is most probably 512MB.
You have options, the easiest would be to use some dynamic drive overlay software (like EZ-drive...) or the XT-IDE BIOS

Dos 3.3 and earlier also had smaller partition size limit if I remember correctly. I remember having to divide 40MB hard drive to 2 partitions back in 1989.

konc wrote on 2020-09-18, 12:17:

The partition size limit is an OS thing, you did well keeping it below 2GB for FAT16.
However there is also the BIOS hard disk limit, which in your case is most probably 512MB.
You have options, the easiest would be to use some dynamic drive overlay software (like EZ-drive...) or the XT-IDE BIOS

So I would flash the XT-IDE bios to a chip and completely replace the bios chip that’s currently on the motherboard?

amalgim wrote on 2020-09-18, 18:57:

konc wrote on 2020-09-18, 12:17:

The partition size limit is an OS thing, you did well keeping it below 2GB for FAT16.
However there is also the BIOS hard disk limit, which in your case is most probably 512MB.
You have options, the easiest would be to use some dynamic drive overlay software (like EZ-drive...) or the XT-IDE BIOS

So I would flash the XT-IDE bios to a chip and completely replace the bios chip that’s currently on the motherboard?

As I understand it from reading other posts, it adds to the motherboard BIOS as an option ROM. You can put it in any add-on card that has an empty BIOS socket, such as, for example, a network card. If you replaced the motherboard BIOS with it, it would not have any of the other code the MB needs, so it wouldn't boot.

As far as I can tell, the motherboard BIOS installs option ROMs during the POST checks and initialisation of the board. XT-IDE only adds more modern IDE routines.

Thanks, that makes so much more sense. I’ll have to pick up an ISA network card with a rom socket.

Cool! Don't forget to download the network card utility, though. NICs have EPROMs for configuration and the ROM socket needs to be enabled for once maybe.

If you like, you can also use one of these older EPROM images.. They are tested and ready to use.
Re: IDE disk-on-module + 386

However, they are several years old by now.
For Win9x, the official 386 versions of XUB are better perhaps.

If you can't get hold of real EPROMs with a quartz window (for erading with UV light), these cheap OTP chips are also worth a try.
But keep in mind that they can't be erased.

The easiest method would be using modern Flash chips or older EEPROMs (essentially the same as Flash). However, finding 27c64 or 27c128 pin compatible chips might be tricky.
Anyway, you can als double the images by using copy command.

Use copy /b rom.bin+rom.bin fatrom.bin or similar syntax. That way, you can use bigger chips (27c256, 27c512 compatibles)

Of course, doing so will take up more space in the 640KB-1MB area..

I hope that wasn't too much information. 😅
It's really simple after you get used to it.
If you like, you can watch some YT video tutorials. I also made a video. Though the other videos are likely better (with speech).

Good luck! 😁

I've just had to to the same thing on an early 486. 500MB just isnt enough!

I went with the EZ-Drive dynamic drive overlay option as I dont have the tools to flash rom chips.
It's easy to setup, works well, and invisable to dos. I had it setup and dos installed in under 1/2 hr
Phil's done a video on it.
https://youtu.be/8LzCB6kDVC8

But if you have all the tools to flash the chip the XT-IDE type solution is the way I'd go.