Very glad I documented what I went through with my CF on the Tandy 1000SX seeing as so many have responded and used this thread.

Dr Xray,

I'm assuming you tried the steps in the original post, specifically

"DISKPART
LIST DISK, found # for my CF.
SELECT DISK #
CLEAN"

in the CMD prompt of Windows 7 to prepare the CF before putting it in the XT-IDE? While this was crucial, no matter what I did there was no way I could FORMAT or install DOS on another machine and then transfer it over -- it had to be all done on the Tandy but this first step had to be done in Windows first.

@infiniteclouds

read that! i also did that (CMD part in Win10)

of course it didn't work.

fdisk on DOS 3.3 gives me 4 options- #4 to list drives /partitions and the CF doesn't appear.

I can't fdisk the only active drive into more partitions as its my boot c drive

my issue might be with the TL2 model itself- i was told by James Pearce to merge bioses- the XTIDE with onboard controller ("dump C000h-CBFFh to a file, copy /b board.bin + ide_xtp.bin newcf.bin and write the option rom to the card... )

i just can't get debug to dump to file. will search for a hex dump program that is dos 3.3 compatible and try to merge/pad the roms, but i doubt i will ever get this to work without very specific instructions!

thanks again

drphilxray wrote:

fdisk on DOS 3.3 gives me 4 options- #4 to list drives /partitions and the CF doesn't appear.

Hey, is this *after* you used FDISK/MBR command from a DOS 5.0 or later FDISK ?

nope- its after i used fdisk on a dos 3.3 system. i have yet to upgrade to 5.0 - waiting on 720kDD disks from ebay.

im just trying to wrap my head around how the XT-IDE boots- I do *not* have PC XT mem map memorized, 🤣!

if the XTIDE-CF board is showing up, but boots from the C: old tandy HD, is the onboard controller really interfering? i *should* be able
to get CF drive (256mb) to show up for FDISK. I barely remember what happens on FDISK for options 1-3 (does it wipe drive right away- leaving
the tandy HD erased or give me a confirm option?)

anyhoo, I know there are a *million* and one issues with getting the right CF card recognized- to include wiping it (hddclean, wipe with 0 etc) on the original system, NOT any modern system, etc.

i think i just need step by step directions to find/fdisk partition/ format fat16B in my old age 😉

I can't guarantee that your issue is the same that I was having but I 100% could not get a bootable 3.3 DOS on my system until I first popped in a DOS 5.0 disc and used THAT fdisk to do an fdisk/mbr. Then I backed out of the installation and popped in 3.3, installed it, etc. and that finally worked.

Same here, but with an IBM 5150. No way to install 3.3 using XT-IDE. It did let me fdisk the disk, but would then freeze on next boot. With 5.0 however, it worked without any issues.

Okay, then I would say the chances are very good Dr Xray that you will have success doing what I did -- use DOS 5.0's FDISK utility to do an master boot record format (fdisk/mbr) then back and pop in your 3.3 disks and install.

yes, dos 5 successfully upgraded (using working 720k FD!) and yet i *still* have to merge the Tandy 1000TL2 onboard HD bios with the xtide cf (the .bin for 286 and better), which i can't figure out using debug command line 🙁

any good hex DOS 5 utils out there that will let me dump mem address to a file and merge bios'?
tks guys

Did you ever solve this? I have a Tandy 1000 TL/2 with an internal 8-bit XT hard drive that I want to replace with CF.

I'm already experiencing massive difficulties trying to get IDE->CF working in a Tandy 2500 XL/2. The IDE->CF adapters and several cards worked on a much newer PC, so the problem is at the Tandy 2500 XL/2. I can't take much more of this, since I've bought multiple cards, multiple adapters, and have had no success. I've considered getting a BIOS card from Monotech, but I don't know if that'll work in the 2500 or if I will need an IDE interface too (there's one on my SB16, but the one integrated into the 2500's motherboard cannot be disabled from what I can see).

I figured I would buy an XT-IDE->CF ISA card for the Tandy 1000 TL/2, but you seem to have struggled with this back in 2019 and I am getting tired of troubleshooting. I just want these things to work. 🙁

EDIT: I solved the 2500 XL/2. Now I’m totally stuck with my Tandy 1000 TL/2. No matter what IDE address I use, or universal BIOS version I use, everything stops dead at trying to boot from or run any programs on the CF card in the Monotech XT-IDE card. Its ROM is at D8000.

Hi, sorry for invading this thread again.. 😅

I know of an alternative that may do.
It's unconventional, needs a V20 maybe, but no XTIDE orbany other software.

It's the classic DiscOnChip 2000 module, aka DOC.
It comes with an internal boot loader and 8-Bit I/O.
You can build yourself a simple ISA card with minimal effort.
Or use it on a network card card, I believe.

https://de.wikipedia.org/wiki/DiskOnChip

https://hackaday.com/2018/03/30/a-retrocomput … disk-on-a-chip/

http://www.daupara.de/surfstation/

https://forum.classic-computing.de/forum/inde … er-isa-rechner/

http://hobby-electronics.blogspot.com/2006/04 … p-2000.html?m=1

If anyone comes looking for the same issues I described in my post above about my 2500 XL/2... I solved it (but now I’m stuck with my 1000 TL/2).

The 2500 XL/2 needed:

This small ISA ROM card:
https://monotech.fwscart.com/DoubleROM_-_IDE_ … 4_19995208.aspx
This ROM card 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.

And a Sound Blaster 16 CT2290, which sidesteps the Tandy 2500 XL/2's crappy integrated IDE controller. It wasn't enough to 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, 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).

Rebooted and the card works fine as a boot device, even though it was partitioned and formatted on a much newer PC. YAY!!

EDIT: PS: I eventually got the 1000 TL/2 working with an XTIDE BIOS card that also has a CF card socket on it... but the Sound Blaster clone (seems to be an ESS Audio Magician Plus) freezes the machine on using its DAC, despite having set it to IRQ5 and DMA3 (the Tandy DAC is bound to IRQ7 and DMA 1). The Tandy DAC works, though.

Hey, necro bump here.

I recently acquired a Tandy 1000sx and am having almost word for the the same issue as the original poster. I'm using the XT-IDE with the SD Card adapter. After much frustration I was able to get DOS 3.1 on C, but it keeps hanging on C>C upon startup. I can get into C by booting the DOS 3.1 floppy. I got COMMAND COM over, and did a *.* transfer from the DOS floppy to C.

Best I can figure for the hanging is because my DOS disk for whatever reason does not include the 2 files IBMBIO.COM & IBMDOS.COM. But really I have no idea...

From reading over this entire thread it seems like people are picking up DOS 5.0 disks on eBay, and using the FDISK utilities in there to create the partition.
Then heading over to DOS 3.2 to finish the install?

Am I understand this correctly?

Also, is DOS 3.1 sufficient, or should I get a later version?

Who is a reputable seller online where I can get premade DOS disks, and any other useful stuff I may need in the future?

Thanks.

boot from the floppy, go to the hard disk, then type sys a: c: (I forget the old syntax, should be correct). this will make c: drive bootable.

dos3.1 is definitely sufficient for a 1000sx.

BloodyCactus wrote on 2026-10-09, 12:09:

boot from the floppy, go to the hard disk, then type sys a: c: (I forget the old syntax, should be correct). this will make c: drive bootable.

dos3.1 is definitely sufficient for a 1000sx.

Unfortunately that gives me an error stating floppy A is write protected.

aaaah maybe its reverse, stay on the floppy and just type "sys c:"

BloodyCactus wrote on 2026-10-09, 13:18:

aaaah maybe its reverse, stay on the floppy and just type "sys c:"

I have already copied everything over from the floppy. I think the issue is that I am missing 2 files.

IBMDOS.COM
IBMBIO.COM

For whatever reason my floppy does not have them.

I ordered a new 3.1 disk, hopefully that helps.

you cant just 'copy' the missing files, thats what sys is for, it copies them over, and they are hidden, you need to use attrib to see them.

+1

IBMDOS.COM and IBMBIO.COM do equal MSDOS.SYS and IO.SYS on MS-DOS.

They're normally invisible due to them having the "hidden" and "system" attribute.

Norton Commander may see and copy them, but that's not really helpful.
Because these system files must be written to at the right spot on the FAT.

Just copying them to a random location doesn't work.
That's why SYS command is there (alternative is FORMAT X: /S).

The only DOS on which that manual copying may work is MS-DOS 7.x, because it has a more advanced boot loader.

Otherwise, COMMAND.COM is the only of the system files that can be manually copied.

Edit: Personally, I think that DOS 5 would be the least trouble some DOS of the vintage series.
Be it classic MS-DOS 5.00a or the earlier DR-DOS 5 that had inspired MS-DOS 5.
If it has to be an DOS 3.x for the sake of authenticity, then I'd consider Compaq DOS 3.31. It has more modern FAT support.

I'm saying this despite being personally more of an PC-DOS 3.30 person.
Because PCD 3.30 was a small part of my childhood it was the oldest DOS that I could relate to.
From a rational point of view, I have to admit that Compaq DOS 3.31 or DR-DOS 3.31 are more useful/stable though.

there were some tandy specific utilities that came with tandy's version of dos 3, which are nice to have. I patched mine to work on any version of dos (I think some had a dos version check, i dont remember, been so long!).

I did use the command SYS C: /S

Also tried FORMAT C: /S

I also tried SYS /S (or maybe is was SYS C) I tried so many things it's hard to remember at this point.

also tried *.*

That did not seem to get me up and running. My C: Partition is saving and selected even after a reboot, it's just hanging on C>C

I tried picking up a DOS/BASIC disk from a seller online, in addition to a utility Disk and Deskmate 2 disk set. The deskmate #1 disk and the DOS/BASIC disk both appeared blank on arrival. I mentioned this to the seller and he sent me 2 new ones, and showed me live in discord that they have files on them. They appear blank as well upon arrival.

I'm not really sure what to do at this point cause I can't seem to get these working, or find something online. Mainly because I have no idea where to get SX disks.

What do you all mean by "use attribute to see them"?

I haven't used a Tandy in like 40 years so I'm a bit rusty on the terminology here.

If anyone thinks there is a solution, and can break it down to an idiot it would be greatly appreciated.

Thank you all for you guidance thus far.