Melbourne Train Control System is running on a hardware emulated PDP11

Apparently, this is no longer the case, and the old emulated PDP-11 system was replaced with a new system in 2014–2016: <a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=29157259">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=29157259</a><p>The old system we are talking about here was Ericsson JZA 715, mostly written in Pascal with some parts in PDP-11 assembly, running under RSX-11M. Melbourne was the first site in the Southern Hemisphere for Ericsson&#x27;s JZA series train control software, going live in 1982. JZA 715 first went live in Oslo in 1979. Earlier iterations of Ericsson&#x27;s JZA software (JZA 410) went live in Stockholm in 1971 and Copenhagen in 1972.

Almost 20 years ago I worked for a company that was bidding on replacing the CRTs that had been rendering platform train information, which was spat out as a stream from said PDP11. I even went to Flinders St and got to see it.<p>It was everything you imagine a 70s era data stream to look like. 1200bps, weird control sequences, etc., etc. And no-one could really tell us much about it, but there was some poorly photocopied incomplete documentation.

The largest nuclear power plant in North America, Darlington Nuclear Generating Station in Ontario, a bit east of Toronto, uses robots for handling the fuel rods. The plant was designed in the late 70s and the control software is apparently written in PDP-11 assembler. And they will keep using it for the remaining lifespan of the plant. So probably long after I retire and I&#x27;m not old. Now that&#x27;s an idea for any young coders looking for a language that&#x27;ll still be in use when they retire; they were hiring maintenance engineers to help keep it running a few years back. Maybe a bit of a dead end skills wise but some of it&#x27;ll transfer to the embedded VAXen that still run half the assembly lines in the same region. (That career advice is sarcastic - probably.)

The toot itself is from 2021, and links to a 2012 PDF* from the &quot;ASPECT 2012 Conference (UK)&quot;, specifically<p><pre><code> 2.10 strangaric - legacy train control system stabilisation.pdf </code></pre> [*] Due to the website&#x27;s interface, navigating directly to <a href="https:&#x2F;&#x2F;webinfo.uk&#x2F;webdocssl&#x2F;irse-kbase&#x2F;ref-viewer.aspx?refno=1559669757&amp;document=2.10%20strangaric%20-%20legacy%20train%20control%20system%20stabilisation.pdf" rel="nofollow">https:&#x2F;&#x2F;webinfo.uk&#x2F;webdocssl&#x2F;irse-kbase&#x2F;ref-viewer.aspx?refn...</a> seems to serve a web page that requires clicking through to request the PDF.

We still run VAX VMS in production. Sometimes I run it on SimH.<p><a href="https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;SIMH" rel="nofollow">https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;SIMH</a><p>You can run it too.<p><a href="https:&#x2F;&#x2F;gunkies.org&#x2F;wiki&#x2F;Installing_VMS_V1.0_on_SIMH" rel="nofollow">https:&#x2F;&#x2F;gunkies.org&#x2F;wiki&#x2F;Installing_VMS_V1.0_on_SIMH</a>

And so do several U.K. high street banks, written in COBOL for the PDP-11, run via an emulation layer of an AS&#x2F;400, last I stuck my head into that particular hell, and I doubt much has changed.

FYI: &quot;The PDP–11 is a series of 16-bit minicomputers originally sold by Digital Equipment Corporation (DEC) from 1970 into the late 1990s, one of a set of products in the Programmed Data Processor (PDP) series.&quot; <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;PDP-11" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;PDP-11</a>

Archive link: <a href="https:&#x2F;&#x2F;web.archive.org&#x2F;web&#x2F;20221225231302&#x2F;https:&#x2F;&#x2F;webinfo.uk&#x2F;webdocssl&#x2F;irse-kbase&#x2F;ref-viewer.aspx?refno=1559669757&amp;document=2.10%20strangaric%20-%20legacy%20train%20control%20system%20stabilisation.pdf" rel="nofollow">https:&#x2F;&#x2F;web.archive.org&#x2F;web&#x2F;20221225231302&#x2F;https:&#x2F;&#x2F;webinfo.u...</a>

Ironically, because of the unbelievably bad infrastructures and general policies, Melbourne because a relatively affordable place to live in Australia. When other capital cities saw double digits property price growth, Melbourne prices actually went down.

Whilst not a train guy, I found this talk at Laracon AU to be pretty entertaining... <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=bbPzSdyroRM" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=bbPzSdyroRM</a>

The emulated PDP-11 was replaced sometime around 2015 by a system from Invensys.

Maybe the PDP-11 is the one running the linked website.