18 Oct
2011
18 Oct
'11
4:43 a.m.
ray at arachelian.com wrote
On 10/17/2011 04:04 PM, vintagecoder at aol.com wrote:
I'll give you an example about the OS I work with, z/OS. It started out in
1964 (arguably earlier) was written in assembler, and was designed from the
beginning to run on one architecture. 47 years later IBM has still not
shown any interest in porting it. The OS and hardware are tightly coupled,
that's one of the main ways the system provides so much throughput. Things
changed recently but IBM was historically a hardware company. They happen
to write fantastic software, but they write it to sell hardware.
When people wanted to port the IBM OS family to x86 they wrote Hercules to
emulate the hardware. The OS doesn't make sense on anything but System/360,
370, 390, Z, etc. It was easier to port the hardware than the software.
A good assembler is perfectly situated for writing an OS and not at all
tedious. But a lot depends on the architecture as well as the assembler.
So, um, what do you do when you want to port your assembly only OS to
x86_64, PPC, SPARC, MIPS, ARM from your original platform? (Re)Write in
C? :-D