1. Operating within the 504MB BIOS limit: Use something like IDE info
Re: Booting a 286 from CF card
and see if you can find some c/h/s values that work. Not guaranteed to work and won't go past 504MB.

2. Overcoming the BIOS limit: DDO software or XT-IDE BIOS. If on track didn't work try another, for example EZ-drive.

Sounds like you have encountered the 504/528MB BIOS limit. Seems likely that your BIOS is older than July 1994.

https://www.vogonswiki.com/index.php/Storage# … compatibilities

Systems with BIOS limitations can be configured to work with larger drives using one of these three techniques:

• Configure the drive with geometry with Cylinders < 1024, Heads <= 16, and Sectors <= 63 in the BIOS and install drive overlay software that replaces the BIOS routines when the boot sector is loaded
• Upgrade your BIOS using a new BIOS from the motherboard manufacturer or from a third party such as MR BIOS that works with your motherboard
• Install an add-in card with an option ROM extension that replaces the BIOS disk routines before BOOT such as XTIDE UniversalBIOS or SIIG Enhanced BIOS

The first option is usually the easiest / cheapest.

An assortment of old drive overlay tools can be found here: http://vogonsdrivers.com/index.php?catid=19&menustate=59,57

I find that EZ drive often is the best if you plan to move your SD between computers, because the partition types & drive geometries that it uses are usually compatible with modern computers.

Dos 6.22 is limited to 2GB partitions using FAT16x file system & normal cluster sizes, so don't make partitions larger than that.

I added EZ drive 9.03 to the library. It might be best for DOS 6.22.

Thank you. Xt ide is the way to go!

And I really appreciated the detailed answers. Saving for later. I got my 286 to 2gb with the xt ide solution and cf. Working on 486 now.

I've had success with EZ-Drive on a very similar setup. I used WhatIDE to get card geometry. But I've always been curious to go the XT-IDE route.

For someone without a programmer, it seems like a preconfigured ROM from Monotech is a cheap & easy route. Or one of their DoubleROM ISA cards. Any thoughts on these options?

https://monotech.fwscart.com/ROM_chips/cat608 … 15_4822253.aspx

https://monotech.fwscart.com/DoubleROM_-_IDE_ … 4_19995208.aspx

My understanding is that most XTide users run the XTIDE config program to modify the ROM image and write configured image to the eeprom.

I have an XTide 4.0 card with a Blue Lava graphic that I got as a gift. Likely was used. The XTIde software lets you use an XTIDE card to write to the EEPROM, but I've often had problems using it to write to the EEPROMS. Perhaps the EEPROMs that I have are not exactly compatible or maybe I got a damaged card. Not sure. I have had better luck using a tl866ii+ EEPROM writer to write the configured XTide images to EEPROMS and put them on old NIC cards for 486 computers.

Never really loved the XTIDE interface, but it is serviceable when it works. I still kind of prefer EZ Drive. Doesn't require hardware and it seems just as compatible at the 386/486 level, but perhaps that's because I'm more familiar with it and I only have a couple old NICs with ROM sockets left.