DOS code in CP/M? Revisited...

Liam Proven lproven at
Fri Jul 15 13:10:24 CDT 2016

On 15 July 2016 at 19:38, geneb <geneb at> wrote:
> On Fri, 15 Jul 2016, Liam Proven wrote:
>> Caldera didn't inherit source code for *all* the old DR products, e.g.
>> many of the apps, but it looked at what it had got, and the bits that
>> couldn't realistically be sold commercially any more, it open-sourced:
>> DR-DOS and PC GEM, mainly.
> Caldera didn't get the sources because much of it was lost when the archive
> in Monterey, CA flooded.  Somewhere around here I've got an inventory of
> what was lost and it's a horror show. :(

Ahhhh... I would both like to see that, and not to see it, IYSWIM.

> All the GEM stuff that could be found was released - including ViewMAX.

Ahh yes. I remember the enhanced versions of that. If you recall, we
were both on the DeltaSoft FreeGEM list, gods, nearly 2 decades ago
now. (!)

>> Then it discovered that actually there was still interest in DR-DOS,
>> took it back in-house again and span off that division as Lineo.
> ...before fully open-sourcing DR-DOS.  The kernel & sources were
> released and then it was canceled.  I contacted them a number of years ago
> about getting the rest released and the weasel I talked to basically had a
> melt down over it.  You'd have though I was asking if it was ok if I
> slow-cooked one of his children.

I recall.

I have one copy of the source-code CD for DR-DOS. I should put up on
Bittorrent somewhere!

> I worked with Roger Gross in '96/'97 to get all this stuff released - it was
> bitterly disappointing when Caldera pulled the rug out from under the
> project.


> For grins I set up a build environment today on a virtual machine - an
> i7-4790K @ 4.0Ghz can build the whole distribution in 20 minutes.  It takes
> 2-3 minutes to build out the disk images. :)  In 1996 it took a 200Mhz
> Pentium 2 hours for the same task.

We don't appreciate how much faster modern PCs are than the old ones,
because modern PC OSes are so appallingly slow and bloated.

Running BeOS on a 200MHz Pentium 1 showed the potential of the
hardware like nothing else I've ever seen on x86.

It was as snappy and responsive as RISC OS was on the early
Archimedes. This is IMHO the definitive review of them, and it is well
worth a read:

I vividly remember reading it as a 19YO student...

"The hard disk in the A500 is most noticeable for its ferociously
rapid access speed. It loads huge programs with a faint burping noise,
in the time it takes to blink an eye. The reason for this speed is
that the disk is run with no interleaving of sectors. On an IBM XT,
for example, the disk rotates about six times between each read to
give the puny CPU time to digest; Archimedes eliminates this dead time
as the ARM processor can suck stuff off the disk as fast as it can

"It felt like the fastest computer I have ever used, by a considerable margin".

... and the amazement of being able to afford one a few years later.

It's by Dick Pountain who later became a colleague and friend.

Also see

As radical a computer as the Amiga, and far more influential -- it's
the origin of the ARM chip and that is _everywhere_ now.

But the OS, although not architecturally radical, was radical in other
ways: live window dragging! Universal real-time font antialiasing!

It felt like the fastest thing ever, as Dick said.

Well, the only OS that's felt like that since, for me, was BeOS.

I'd _love_ a modern BeOS on a modern multiprocessor PC. But nothing
like it exists any more, and Haiku is nothing like as snappy.

If I were a billionaire, I'd buy Access ( ), give the BeOS
sources to the Haiku guys and sponsor them to update it. All it really
needs today is a built-in hypervisor -- then you could run something
bloated like Linux in a VM to get a modern browser etc. while some
native ones were developed or ported.

Liam Proven • Profile:
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