I was a twenty-year-old college #dropout who had lucked into the job after the department’s director noticed that his temporary secretary (me) was way better at automating repetitive tasks in #Microsoft Office than typing up memos.

So he hired me outright (neglecting to increase my administrative-assistant-level wage 😖) and set me loose helping the engineers with their Sun #Unix workstations and #Intel #i486-based PCs running #Windows for Workgroups. (2/6)

Before moving to greener (and higher-paying 🤑) pastures, one of my two big "technical assistant" projects for #Comcast #Cellular was upgrading the engineers' Sun #Unix workstations from the #BSD-based #SunOS 4 to #SVR4-based SunOS 5 (#Solaris 2), and from #NIS / #YellowPages to NIS+.

In hindsight, it was a bad idea to make both changes at once, but I was a kid entranced by novelty and not yet very considerate of my users during the inevitable downtimes. (3/6)

I had previously whipped up an #Excel #VisualBasic for Applications (#VBA) Erlang B function to calculate #cellular tower quality of service (#QoS), so my other big project was modeling #Comcast Cellular’s network call capacity for an overdue upgrade from the (analog!) #1980s-era Advanced #Mobile Phone System (AMPS).

My first corporate #programming lesson: toy code will be expanded regardless of scalability. (4/6)

IIRC, any given AMPS antenna could only handle about 400 #mobile phone calls at once, and there were usually three antennae spanning the 360º around a #cellular tower. Busy areas often dropped phone calls as users were handed off between antennae.

Hmm, the #Wikipedia inverse Erlang-B #VisualBasic function bears a striking resemblance to my 1994 code… (5/6)

(attached image extracted from en.wikipedia.org/wiki/Erlang_(… by #Wikipedia contributors, licensed CC BY-SA 4.0 creativecommons.org/licenses/b…)