<div dir="ltr">Matt,<div><br></div><div>First, sorry for the delayed response.</div><div><br></div><div>In around 1994 through late 1996 I worked on the FlashPort project in Bell Labs.</div><div>A significant project that we completed was FlashPort'ing the 4ESS SWAP assembler from TSS/360 to Solaris.</div><div>My memory is that the 4E team wanted to get off of TSS and onto Unix.</div><div><br></div><div>Alan</div><div><br></div><div><a href="https://techmonitor.ai/technology/emulator_house_echo_logic_folded_back_into_att" target="_blank">https://techmonitor.ai/technology/emulator_house_echo_logic_folded_back_into_att</a><br></div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Apr 5, 2024 at 12:59 AM segaloco via TUHS <<a href="mailto:tuhs@tuhs.org" target="_blank">tuhs@tuhs.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">So I've been doing a bit of reading on 1A and 4ESS technologies lately, getting<br>
a feel for the state of things just prior to 3B and 5ESS popping onto the scene,<br>
and came across some BSTJ references to the programming environments involved<br>
in the 4ESS and TSPS No. 1 systems.<br>
<br>
The general assembly system targeting the 1A machine language was known as<br>
SPC-SWAP (SWitching Assembly Program)[1](p. 206) and ran under OS/360/370, with<br>
editing typically performed in QED. This then gave way to the EPL (ESS<br>
Programming Language) and ultimately EPLX (EPL eXtra)[2](p. 1)[3](p. 8)<br>
languages which, among other things, were used for later 4ESS work with cross-<br>
compilers for at least TSS/360 by the sounds of it.<br>
<br>
Are there any recollections of attempts by the Bell System to rebase any of<br>
these 1A-targeting environments into UNIX, or by the time UNIX was being<br>
considered more broadly for Bell System projects, was 3B/5ESS technology well on<br>
the way, rendering attempting to move entrenched IBM-based environments for the<br>
older switching computation systems moot?<br>
<br>
For the record, in addition to the evolution of ESS to the 5ESS generation, a<br>
revision of TSPS, 1B, was also introduced which was rebased on the 3B20D<br>
processor and utilized the same 3B cross-compilation SGS under UNIX as other 3B-<br>
targeted applications[4]. Interestingly, the paper on software development<br>
in [4](p. 109) still makes reference to Programmer's Workbench as of 1982,<br>
implying that nomenclature may have still been the norm at some Bell Labs sites<br>
such as Naperville, Illinois, although I can't tell if they're referring to<br>
PWB as in the branch of UNIX or the environment of make, sccs, etc.<br>
<br>
Additionally, is anyone aware of surviving accessible specimens of SWAP<br>
assembly, EPL, or EPLX code or literature beyond the BSTJ references and paper<br>
referenced in the IEEE library below? Thanks for any insights!<br>
<br>
- Matt G.<br>
<br>
[1] - <a href="https://bitsavers.org/magazines/Bell_System_Technical_Journal/BSTJ_V58N06_197907_Part_1.pdf" rel="noreferrer" target="_blank">https://bitsavers.org/magazines/Bell_System_Technical_Journal/BSTJ_V58N06_197907_Part_1.pdf</a><br>
[2] - <a href="https://ieeexplore.ieee.org/document/810323" rel="noreferrer" target="_blank">https://ieeexplore.ieee.org/document/810323</a><br>
[3] - <a href="https://bitsavers.org/magazines/Bell_System_Technical_Journal/BSTJ_V60N06_198107_Part_2.pdf" rel="noreferrer" target="_blank">https://bitsavers.org/magazines/Bell_System_Technical_Journal/BSTJ_V60N06_198107_Part_2.pdf</a><br>
[4] - <a href="https://bitsavers.org/magazines/Bell_System_Technical_Journal/BSTJ_V62N03_198303_Part_3.pdf" rel="noreferrer" target="_blank">https://bitsavers.org/magazines/Bell_System_Technical_Journal/BSTJ_V62N03_198303_Part_3.pdf</a><br>
</blockquote></div>