Do you want official MS-DOS or would FreeDOS meet your requirements?

I would vote for the Book8088 or Pocket386 for pure DOS just because it has the screen and keyboard. Otherwise a WeeCee would have been the tiniest, but it needs a screen and a keyboard and power.

If you could get the Surface3 to boot to DOS, that would be fantastic, as it's really slim and convenient! I have a Surface4 which I replaced its battery and storage to 2TB and I use it for D3D12 development. It's quite capable even today...

Not a big fan of FreeDos (was involved in it a bit a first - had "friction" with some if the devs, haven't
looked back) - I'm an old-school DOS guy ... I have MS-DOS 5 on most of my actual DOS systems.

It doesn't have to be pure DOS - just good DOS compatibility.
The Digital2 tablet is Win8/32 - and it provides pretty good DOS compatibility.

On more powerful systems (like my desktop) I use DosBox a lot, and it works well.
(I can even boot pure DOS under DosBox if I really need to run something under DOS itself)

The "big factor" for me is size ... The Digital2 with the shown keyboard/mouse is really tiny,
allowing me to fit in lots of places without needing a separate laptop bag or consume significant
space in a carry-on suitcase.

It's also quite a few years old... I'm basically asking if there is anything of comparable size available
now that would be significantly more powerful and still at least Win32 compatible or be able to run
DosBox reasonably.

The Digital2/Win8 also has some weird quirks I'd like to say goodbye to ...

Since my compiler uses a few temp files, and not wanting to repeatedly write to flash, I
use a small RamDisk - the RD software I use works properly in my other systems, but on this
Tablet, even though I have it set to not save an image of the RamDisk at power off, it obviously
doing so somewhere ... it doesn't "lose it's content"!

The tablet sometimes doesn't power-off correctly... Win8 goes through the motions and appears to "shutdown",
and the system becomes "dead" (screen off, no response to user input) - but obviously continues to draw
power - gets warm if put away in a padded case I have for it - battery depletes to the point where the tablet
won't start until charged (via microUSB) for 10 mins or more..

temu/aliexpress have a number of 7" super portable windows 11 laptops that I've considered using as a more or less dedicated dosbox system.

https://www.youtube.com/watch?v=mIOKDe4phkA

They seem to be reasonably high quality, but shared function keys and number keys is a bit of a bummer...

Osborne-1 ( year 1981 )

A bit bigger but one of my laptops is an HP with a 10th Gen Intel i7. It is a 2-in-1 and is very thin and light. I take it with me when I don't want to take anything larger.

It is a 13.3" screen though so quite a bit larger than what you have now.

Do a google search for
Tiny laptop
And go from there.

The smaller you go, the less power available.

Intel486dx33 wrote on 2025-05-10, 14:16:

Osborne-1 ( year 1981 )

I already have one of those!

(See "Daves Old Computers")

cyclone3d wrote on 2025-05-10, 15:01:

A bit bigger but one of my laptops is an HP with a 10th Gen Intel i7. It is a 2-in-1 and is very thin and light. I take it with me when I don't want to take anything larger.

Getting something bigger is not a problem. Not long ago the same friend who gave me the Surface gave me
a Lenovo T440! Nice and thin, good screen keyboard, and almost as powerful as one of my main Desktops
(I7, 12gRam, 256gSSD) - not hard to pack, but still takes up more room than I'd like....

Interesting story behind it - he's in IT and has such things come/go all the time - Its wifi module had failed .
He swapped it out with one from his junk box, only to get "Unable to boot - remove the non-Lenovo wifi module"
... so he pulled it back out, then it wouldn't "do anything" (black screen), and he gave up on it.

I happened to notice it sitting on his table one time when I visited, he told me what had happened, then
said "take it if you want it".

When I took it apart, I noticed that the antenna wires for the now-removed wifi module were just laying in
very thin space under the mainboard, and guessed that the metal connector "caps" might have been shorting
something...

So I put "black tape" over them, then re-assembled... it came up and works perfectly (still without Wifi)
My easy solution was to pack a (cheap on Temu) Wifi/Bluetooth USB in the bag with it - now it's one of
my favorite laptop!

The smaller you go, the less power available.

When travelling, I don't often need much in the way of power... I've always been an "early riser", and
having a few hours to kill every morning, I still like to dabble with developing "stuff" in DOS... (DosBox
works as well)

For the usual web browsing, email, video(incl monitoring home cameras), music and even a few games,
I use another (Android) tablet (I even have a tiny "8Bitdo Zero" game controller) - I've not found DosBox
on Android good enough for my use case, so I carry the extra Win8 tablet - just for that.

I own Asus Transformer T100HA and I had T100TA before. These are UEFI devices so there's no option to boot in pure DOS. Portability is great with ability to charge it with microUSB port. If you know that there is a good charger > 1A and good USB cable in the place where you go that will save you some additional space. And even if you take charger with you it won't take as much space as big laptop charger.

I had some hardware issues with both so I wouldn't recommend them unless portability is your priority. Still I use it everyday and it's hard to replace it as I don't think any new devices compete in this area.