DOS ain't dead

I tried it, and it works perfectly !
It takes only 496 bytes of low memory.
And finally it unload without any problem with the "u" switch.

> brand new int 15h method is used to communicate with an installed
> instance of KBFR.

I'm not a fan of overloading interfaces with magic values like that.


orgint15's address is hardcoded in the uninstaller. Why? If you hardcode things, you might as well hardcode the kvar address instead of returning that in your interface.

Your interface still contains some unused fields?

The trans function still isn't inlined, as you noted in the comments.

Your interrupt handler still isn't using the interrupt sharing protocol.

Your uninstaller still doesn't walk interrupt sharing protocol handler chains and doesn't query AMIS TSRs for their chain entries.

You sometimes discard the saved flags by returning with "retf 2" from an interrupt handler.

Your arguably ineffectual critical section protection doesn't appear to be necessary any longer, as you aren't using any data in the freed area. You can use 21.49 to free the previous PSP's area then.

You still free the environment only inside the (non-)critical section, and manually. I'd use 21.49 again.

Where it says "calculate resident size", the calculation always appears to yield the same value so you might as well hardcode (size+15)>>4 with the assembler.

Still not checking for errors after 21.48. Can't happen? I can write a fully compatible TSR which might make just that happen. What then? You'll overwrite 496 bytes at 0008:0000 (linear 00080) then, incidentally trashing interrupt vectors 20h til about A0h.

I guess that's all for now.

---
l