I missed out on the System/38. I worked in the old IBM General Business
Group when it replaced the 34 and 36 range.

In those days, DP division (Mainframe) always won out if there was a
customer looking for a suitable system. Thos were the days of the antitrust
case and we were told that there may be a split of the various divisions.
Unfortunately, it didn't happen.

A couple of years later, I worked on a 4331 that utilised 3310 drives
(piccolo drives because that was how they sounded when the heads were
clunking in and out). The 3310 drives were a temporary replacement for
failing 3370 FBA devices that were suffering HDA crashes.

On Wed, Sep 11, 2024 at 3:12 AM Mark Waterbury <
[email protected]> wrote:

>  Not quite a "mainframe" but very similar
> See:
> https://www.gofundme.com/f/ibm-system-38-computer-rescue-and-restoration
>
> The IBM System/38 used IBM 3310 FBA DASD, and the "channel" hardware was
> the same as used in the 4331/4341, with different microcode.
> Announced in 1979 and delivered in late 1980 to early 1981, the IBM
> System/38 was the world's first commercially available system to implement
> "single level storage" where all DASD was formatted as 512 byte pages, and
> the entire system ran in a single enormous address space, with 48-bit
> addresses in the "hardware" (microcode/firmware), and at the application
> level, (MI assembler and all HLL compilers) saw only "system pointers" that
> are 16 bytes or 128 bits, on a 16-byte boundary, and approx. 96 of those
> bits were used for addressing.   IBM System/38 implemented over a terabyte
> of virtual address space, way back in 1980!
> IBM S/38 systems were all CISC based, with an instruction set very similar
> to 370 ISA, with 48-bit wide registers.  They were microcoded machines,
> using the same technology as used on IBM mainframes of the period.  The
> memory hardware provided additional "tag bits" to protect MI pointers from
> being modified by software, instead of using official instructions or
> APIs.  If some user code accidentally (or on purpose) modified any bytes
> within a 16-byte quadword pointer, the memory hardware/microcode would
> "reset" the tag bits so the next attempt to use that pointer as an address
> would result in an exception message.
> IBM System/38 included an integrated relational database, released to
> customers well before SQL/DS or DB2 became available.  S/38's (unnamed)
> database did not use SQL (yet), as that was still a new language.   All
> "files" on S/38 CPF are "database" files.  There really was no traditional
> "file system" on disk -- you had named objects in named libraries, all laid
> out in the vast single-level store address space.  The MI instruction
> RSLVSP (resolve system pointer) allowed the CPF OS or user applications to
> "resolve" an object name to its 16-byte System Pointer address.
> S/38 was all made available to customers several years before MVS/XA
> became available.
>
> Please consider contributing to this worthy cause. :-)
>
>
>
>
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-- 
Wayne V. Bickerdike

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