My first “PC” (my third personal computer) was a Taiwanese XT clone. I think it was a “Chingao!”
Anyway, I noticed that it messed up the system time every time a certain application program (my packet radio BBS) queried the time between midnight and 1 AM.
In those days, the (8086 assembly language) source code for the IBM XT bios was printed in the XT manual.
I had access to an EPROM programmer at work; so I pulled the chip, read it out in the programmer, and studied the disassembled code. I found it was nearly identical to that of the XT BIOS, except for the midnight rollover code, which the Clone XT BIOS writers had gratuitously hacked, breaking the rollover. The reason for their hack will ever evade me.
Anyway, I found a way to patch the EPROM image, in 8086 machine language, to fix the routine so that it worked properly, like the IBM XT BIOS.
Blasted it into another EPROM, plugged it into the Chingao, problem solved.
That ol’ clone survived BBS use (24x7) for a few years, even after a fan failure left it hot enough to cook eggs for a couple of days.
Things were sure simpler back then!
The CIA may have an opening for you.
i never learned programming, but i had an old Win. 3:1, with (i think) a 1440 modem, and it has MS word and would work today for word processing. Also spent lots of time on W/95/98/98e/Vista. If they let W/9x (system resources low, fatal error, illegal action, danger Will Robinson) be open source it could still be popular for some old PCs. Thank God for such tools. But things like “write.exe” have not changed much in 15 years.
Before the internet, I was smack on any dx spots... ah the olden days!