If memory serves the one real thing that cloners couldn't duplicate, maybe
due to copyright, was the ROM BASIC but that they'd duplicated everything
else including the BIOS or a very good part of it. That pretty much led to
IBM losing a lot in the PC market.
Now why they kept the BASIC on ROM even into the PS/2 line is beyond me. It
served no real purpose that late in life when most people had moved on to
C++ and Pascal and it was rare to find someone that used BASIC or BASICA -
especially since the cassette port was gone as of the XT 5160.
The BASIC on ROM was in 40 column mode at start as well, I guess to
accomodate any display that might be attached.
-> -----Original Message-----
-> From: owner-classiccmp(a)classiccmp.org
-> [mailto:owner-classiccmp@classiccmp.org]On Behalf Of Glen Goodwin
-> Tony, I think you are correct as I've never seen a clone mb with BASIC in
-> ROM, but I *have* seen clone boards -- including early Pentium boards --
-> which would cough up "no rom basic" if they didn't find a
-> bootable device.
-> Oddly enough the text of this message is always displayed in 40-column
-> low-res mode. Doesn't this suggest that part of the ROM BIOS code was
-> "borrowed" from early IBM code?