5 Dec
2018
5 Dec
'18
6:08 a.m.
On 12/4/18, Greg 'groggy' Lehey <grog(a)lemis.com> wrote:
On Tuesday, 4 December 2018 at 15:59:46 -0500, Paul
Winalski wrote:
No, not start-from-scratch. They modified the existing MIPS TAL front
end to generate GEM intermediate language. I don't know if the TAL
front end generated GEM IL directly or if they wrote some sort of
IL-to-IL translator wedge. IIRC we didn't need to do any object file
work in GEM to support Tandem because they were already using an
object file format we supported (ELF or COFF).
I forgot one: Tandem NonStop OS on Alpha, which was under development
at Compaq at the time that Compaq decided to sell off the Alpha
technology to Intel.
Was this a start-from-scratch operation? The original Tandem OS
(called Guardian at the time) was written in Tandem's TAL (Transaction
Application Language, amongst other productions), a vague evolution of
HP's SPL that looked more like Algol, starting in about 1974. That is
also the earliest I know of an operating system being implemented
entirely in a high level language. When Tandem started using other architectures (MIPS)
in the late 1980s
we discussed translating the whole thing to C. I was asked to write a
99% translator (maintaining comments and such), and failed.
IIRC some of the Tandem code was in C at this point (1999) but a TAL
for Alpha was also needed.
-Paul W.