On 7/15/2013 10:29 AM, stephen.hunt at
iname.com
wrote:
Off topic question - is there any type of S/34 or
S/36 virtual machine?
The AS/400, iSeries, System-i, or whatever name you want to
call it supports S/36 mode and S/36 virtual machines...or at least it did up until a
certain release of OS/400.
I can clarify that somewhat ...
From its inception in 1988, OS/400 (the operating system of the AS/400,
AS/400e, iSeries, System i ...) has had a "System/36 Environment",
including an OCL interpreter, and an RPG II compile, so you could
"port"most of your System/36 applications over to OS/400 and run them
there. But, you had to move "source code" and recompile. So, this is
not an "emulator" or "simulator" but a "runtime
environment". That
option was not too popular with IBM's S/36 customers, in the early
years, because of the higher cost of the AS/400 systems, and the effort
involved. Also, this did not allow migrating any "assembler"
subroutines. Also, the performance was not fabulous on the IMPI
CISC-based AS/400 machines.
So, starting with V3R7 and the first RISC-based AS/400s, IBM introduced
the "Advanced 36" models -- this provided a true emulator or "virtual
machine" -- you could install this Advanced 36 emulator directly on top
of the hardware (the SLIC kernel) on the model 236, or on the 436, you
could run OS/400 and up to three S/36 "virtual machines" (under OS/400).
Support for these *M36 virtual machines continued from V3R7 through
V4R4, or a span of about10 years. IBM felt this was sufficient time to
allow most S/36 customers to migrate their applications and convert them
to "native" OS/400 applications. Amazingly, there are still quite a few
satisfied customers running their S/36 applications on these *M36
virtual machines under OS/400.
This is a very faithful reproduction (emulation) of the original
System/36 hardware, since it was developed by IBM Rochester Laboratory,
where the original S/3, S/32, S/34 and S/36 were developed -- so the
developers had access to all of the hardware designs, microcode
listings, and software source code, etc. -- AFAIK, customers could
migrate and run 100% of their S/36 applications to the Advanced 36 *M36
virtual machine running under SSP 7.1 or 7.5.
(IBM has a long and rich history of writing emulators and simulators --
when the IBM System/360 family was introduced, various models of 360
supported emulators for the 1401,, 7094, etc. 0 IBM's previous
generation of "mainframes").