On 03/23/2017 06:58 AM, Tom Marchant wrote:
> On Thu, 23 Mar 2017 02:27:32 +0000, scott Ford wrote:
>
>> One of my first sysprog jobs was on a 370-155 un-dated ..no dynamic address
>> translation ran Intel's DOS look-a-like.
> ITYM IBM Disk Operating System, which predated Intel by years.
> It is nothing like MSDOS. Did Intel ever have a DOS?
>
No, I'm pretty sure he instead means Itel DOS. I think it was
compatible (from application standpoint) with IBM DOS/VS but ran on 360
architecture without DAT.
The company I went to work for in 1978 was running all corporate
computing under Itel DOS on two IBM 360/65 processors with 1 MiB
central memory each (also from Itel) and Itel 3330 compatible DASD and
tape drives after an upgrade attempt to IBM 370 combined with an attempt
to run VM to enable a migration path to MVS failed miserably because the
370 turned out to have insufficient real memory to run the existing
workload. Itel's offer to back out the 370 and replace with dual
360/65's was the fastest and cheapest fix to get things functional
again. We had resident CE's from both Itel and IBM (who worked quite
well together).
Around 1980 we were finally able to convert to two IBM 4341's with
DOS/VSE, but still ran with Itel DASD and tape for many years. It took
until 1985 before management could be convinced to repeat the attempt to
migrate to MVS, this time with an IBM 3033 under VM with multiple
DOS/VSE systems and a IBM 3083 under VM XA Migration aid for DOS/VSE and
MVS/XA systems. By the time we finally did get off DOS/VSE we were
seriously constrained by the limits DOS/VSE placed on virtual memory,
despite running the max of four coupled DOS/VSE systems with shared
POWER spool.
Joel C. Ewing
--
Joel C. Ewing, Bentonville, AR jcew...@acm.org
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