Matt,

First, sorry for the delayed response.

In around 1994 through late 1996 I worked on the FlashPort project in Bell
Labs.
A significant project that we completed was FlashPort'ing the 4ESS SWAP
assembler from TSS/360 to Solaris.
My memory is that the 4E team wanted to get off of TSS and onto Unix.

Alan

https://techmonitor.ai/technology/emulator_house_echo_logic_folded_back_into_att


On Fri, Apr 5, 2024 at 12:59 AM segaloco via TUHS <tuhs@tuhs.org> wrote:

> So I've been doing a bit of reading on 1A and 4ESS technologies lately,
> getting
> a feel for the state of things just prior to 3B and 5ESS popping onto the
> scene,
> and came across some BSTJ references to the programming environments
> involved
> in the 4ESS and TSPS No. 1 systems.
>
> The general assembly system targeting the 1A machine language was known as
> SPC-SWAP (SWitching Assembly Program)[1](p. 206) and ran under OS/360/370,
> with
> editing typically performed in QED.  This then gave way to the EPL (ESS
> Programming Language) and ultimately EPLX (EPL eXtra)[2](p. 1)[3](p. 8)
> languages which, among other things, were used for later 4ESS work with
> cross-
> compilers for at least TSS/360 by the sounds of it.
>
> Are there any recollections of attempts by the Bell System to rebase any of
> these 1A-targeting environments into UNIX, or by the time UNIX was being
> considered more broadly for Bell System projects, was 3B/5ESS technology
> well on
> the way, rendering attempting to move entrenched IBM-based environments
> for the
> older switching computation systems moot?
>
> For the record, in addition to the evolution of ESS to the 5ESS
> generation, a
> revision of TSPS, 1B, was also introduced which was rebased on the 3B20D
> processor and utilized the same 3B cross-compilation SGS under UNIX as
> other 3B-
> targeted applications[4].  Interestingly, the paper on software development
> in [4](p. 109) still makes reference to Programmer's Workbench as of 1982,
> implying that nomenclature may have still been the norm at some Bell Labs
> sites
> such as Naperville, Illinois, although I can't tell if they're referring to
> PWB as in the branch of UNIX or the environment of make, sccs, etc.
>
> Additionally, is anyone aware of surviving accessible specimens of SWAP
> assembly, EPL, or EPLX code or literature beyond the BSTJ references and
> paper
> referenced in the IEEE library below?  Thanks for any insights!
>
> - Matt G.
>
> [1] -
> https://bitsavers.org/magazines/Bell_System_Technical_Journal/BSTJ_V58N06_197907_Part_1.pdf
> [2] - https://ieeexplore.ieee.org/document/810323
> [3] -
> https://bitsavers.org/magazines/Bell_System_Technical_Journal/BSTJ_V60N06_198107_Part_2.pdf
> [4] -
> https://bitsavers.org/magazines/Bell_System_Technical_Journal/BSTJ_V62N03_198303_Part_3.pdf
>