I had been struggling to get a working mass storage device in my Tandy 2500 XL/2 computer. The factory supplied 52MB "SmartDrive" IDE hard drive developed the typical "sticky" head arm problem found in all the old Quantum drives from 1989 and earlier (the stoppers are rubber; the rubber degrades and becomes literally sticky). I managed to get the drive to start one last time (per a YouTube video instruction, I literally opened the drive and moved the head arm while it was trying to initialize; it felt SO WRONG, but it worked) and copied all the contents to a WinXP machine.

The next problem was an IDE to compact flash adapter and cards. After numerous failures, I ended up with the following components working as desired:

• Transcend Industrial Grade CD220I 512MB compact flash card
https://www.oempcworld.com/OEMPCworld-com/500259.html

• StarTech.com 3.5in Drive Bay IDE to Single CF SSD Adapter Card Reader (35BAYCF2IDE)
https://www.amazon.com/gp/product/B000T9QQP0/
This is mounted in a cheesy plastic StarTech 5.25" bay converter. I had another adapter, which works fine in another PC, but didn't come with mounting hardware, so I got the StarTech one (also to test if the other adapter was problematic, which is not the case).

• This small ISA ROM card:
https://monotech.fwscart.com/XT-IDE_Deluxe_-_ … 4_19478732.aspx
This ROM card has XTIDE Universal BIOS on it. It sidesteps the Tandy 2500 XL/2's BIOS' IDE controller-related functions. I had to go into the Tandy BIOS setup (setupxl2.exe) and mark both primary and secondary drives as "none", since the ROM card fills in for that stuff on boot. You could do the same with an ISA ethernet card if it has a boot ROM that you can replace with XTIDE Universal BIOS, but I didn't, so buying this card from someone was the easiest way for me to go. I also bought the "XT-IDE Deluxe" CF reader ISA card from the same seller for my Tandy 1000 TL/2, but haven't started on that project yet (the old MFM hard drive still works, but who knows for how long).

• A Sound Blaster 16 CT2290, which has a more modern IDE controller on board. This sidesteps the Tandy 2500 XL/2's crappy integrated IDE controller. It wasn't enough to just have the ROM card, since the Tandy 2500 XL/2 IDE controller cannot handle the compact flash cards I've tried to use. I set the SB16's IDE controller address to 170h, IRQ 15 (to make sure it doesn't conflict with the Tandy motherboard's integrated IDE controller), ran the ROM card's XTIDECFG.COM config tool, selected "detect..." and everything came up just fine. It even ignored the Tandy's internal IDE controller, telling me there was only 1 IDE controller (the SB16's). After flashing the settings to EEPROM, I rebooted and all was well.

The card works fine as a boot device, even though it was partitioned and formatted on a much newer PC. So that means it can be put in another computer to download software from the internet (or set up with DOSBox), and put back in the Tandy 2500 XL/2. YAY!!

I hope this info is useful to someone else.