HP110+ upgrade DOS2.11 to DOS6

[Martin Hepperle]

.. as brouhaha said above, you first have to adapt the low level components of DOS to the HP hardware.

This part is required to access things like the mass storage (which typically is a combination of RAM and ROM disk), timing hardware (clock), keyboard and so on. In the old days, Microsoft supplied an OEM adaptation kit which contained the description and examples how to adapt MS-DOS to non IBM-PC compatible hardware.

This would require quite some effort and later MS-DOS versions would also use more RAM which is scarce on the Portable Plus.

If you want to use your soldering iron: a more interesting hardware development would be to design a large capacity RAM disks drawer.