Somewhat correct, but probably not exact, as the limits are created from particular BIOSes and the bugs they have.

For me, if the drive doesn't work right, I'll just mod the BIOS (for some award BIOSes) and fix it that way, and if the BIOS cannot be fixed, then use XT-IDE on my ethernet card.

It depends on the Operating System. NT Workstation SP6a and higher NT (2000, XP, Vista, and 7) supports the full drive capacity, if and only if the drivers are installed for everything. And some 486 systems did support up to 8.4GB for the drive limits, depending upon the BIOS and other factors.

For the drive limits, it always depended on the BIOS, board manufacturer, and a few other factors, like chipsets. Older systems from the 8088-486 required an add-on controller card in order to use the hard drives and the XT-IDE Universal BIOS supports bigger hard drives that blows past the motherboard's drive limitations, and that also includes Ontrack Dynamic Disk Overlay. And I'd say, you might be right on the drive limit for Socket 370/462(A) systems, and, as I stated earlier, it depends on the Operating System. MS-DOS and Windows 9x had capacity support from <512MB-137GB, and Windows NT 4.0 SP1-SP3 supported up to 7.8GB, SP4 and higher, 2000, XP, and higher supported more than that, as long as the chipset drivers were installed. Windows 2000 supported up to 120GB in storage space before the chipset drivers were installed and supported more than that afterwards and was impossible to expand the storage capacity to the full one, if my memory serves me right.

I use the XT-IDE Universal BIOS on my 3Com EtherLink III 3C509 ISA card on my Packard Bell Pack-Mate 28 Plus to support bigger drives over 2.1GB, however, Windows 95 begs to differ and states that the drive is running in 16-bit mode over 32-bit mode.

You might want to read some basics about PC hard disk size limits first...

I think BIOS decides the HDD limit first, then the operating system. However, the BIOS limit may be overridden with utilities such as Dynamic Disk Overlay.

I once had an old Socket 7 system with Acer V30-II motherboard and it appeared to only work natively with hard disks of 2GB or less (any size higher will have issues), despite the system info screen (where CPU, memory and HDD info were shown) can show up to 8GB. Tools like Ontrack DM's Dynamic Disk Overlay can break this limit and allows you to use some larger disks (the highest I tried were 40GB).

I also read somewhere that chipsets such as 440BX had a hard limit of 128GiB, although the largest disks I ever tried on such chipset were 120GB SSDs, which is below that limit, so I cannot confirm that. If it were true, maybe it can be broken using Dynamic Disk Overlay utilities. I personally didn't recall seeing disk limits on Socket 370 or 462 motherboards (but it's still chipset-dependent).

Even though you might break the limit with Dynamic Disk Overlay, early chipsets and operating systems might have an absolute hard limit of 2TB (due to MBR using only 32 bits for sector addressing). I once had a 3TB disk on an i865 chipset motherboard with Windows XP (used Windows 2003's disk.sys for GPT support), and I ended up corrupting stuffs when I tried storing stuffs to spaces beyond 2TB (and had to do a thorough chkdsk). After digging a bit online, it seems some users experienced corruptions even on Windows Vista/7 with 3TB (GPT) or higher disks and with older motherboards, so on earlier chipsets, some limitations might be even harder to overcome (historically, 3TB external hard disks came out before internal ones, as those disks used true 4K sectors instead of 512e/AF which in theory allowed safe operations beyond normal MBR sector/capacity limit).

I have this BIOS 7.8 Gig barrier problem.
Mainboard is Chaintech 6bjm0 with celeron 400Mhz. Bios detects 64Gb CF card as 8.7 GB drive.
I tried to install with EZ-Drive but it sees also only 7.8 GB of drive capacity. What i do wrong? Should i enter manally different drive parameters in bios?

Is it award based BIOS when it boots?

I usually use Promise PCI addon cards like Ultra100TX or 133 series. It has it's own BIOS and works fine. I used it first time in 2000/1 when my P-II wouldn't recognize my then new WD 80GB 7200 IDE drive.

i wouldn't take that as gospel. ive had:

a 486 with the 504mb limit
a p2 266 with the 8.4gb limit
a p2 350 wirh the 8.4gb limit (different model mb than above)
a socket 370 with a limit below 120, bios only displays up to 65535mb