Re: Sometimes, legacy tech is just legacy. Like Jake.
In 1985 (nearly a decade and a half before your 5MX), I used ComDesign statmuxes and pre-strung serial cables, sometimes/often with Anderson-Jacobson dial-back modem-pairs, to reconfigure sodding bits of misbehaving hardware both on-campus and all over the world. From the Sun Workstation on my desk in my clean, cool office. I still do, as a matter of fact, on my personal distributed network. The Sun is now an aging HP laptop running Slackware, but little else has changed.
Climbing a ladder in this situation is ... well, to put it mildly, fool hardy. A proper data center would never require such a bit of physical exertion for text access to a server with a titsup GUI. Me, I handle it from my desk.
Butt in the saddle time. That's the only way to learn ...