Last Updated or created 2022-11-27
I got a free mainframe, when i was about 17.
It was a huge Pdp-11/34 which a had to get from Enschede to Holten using a trailer.
- It was a 19inch rack (loads of metal)
- 2x 8inch floppy drives
- 2x 20MB harddisk drives (with cardridge) each 34KG!
- multiple (3?) Decwriter III printers
- loads of VT100 terminals
- 2.5 meter of manuals
- cables
- disks (8 inch) and harddisk cartridges
I converted the power to a generic 230V connector. When booting the machine all the lights in the house dimmed.
I didn’t know anything about mainframes, but i got things working.
Sometimes i would play with it, but after a while it didn’t run anymore.
I’ve kept some of the parts of the machine.
Terminals we used for a long time to connect to a linux server.
( The VT100 where later switched for more modern Wyse terminals )
Some parts i’ve kept
Serial printer
These printer we used for generic printing, and just for fun.
They made a lot of noise, and even they are serial printers they are fast!
So i resourced ms-dos into assembly and printed that, that was a sh*tload of paper.
We even made a racing game. (Can’t find the source, but i’ve recreated a lookalike in linux-bash)
Object of the game was to keep your car O character on the road.
The printer printed the lines, and you could use the keyboard to move your car, which also got printed.
Below the build-in-5-minutes bash lookalike. ( z left, x straight and c right)
Original had more intricate road, and probably the road was drawn using two lines, to speedup printing (Decwriter III could print at 180 characters per second bidirectional!)
#!/bin/bash i=0 j=0 car=8 while true ; do no=$(awk "BEGIN{print sin($i*atan2(0,-1)/180)*40+40}" | cut -f1 -d.) way=$(awk "BEGIN{print sin($j*atan2(0,-1)/180)*10+13}" | cut -f1 -d.) #echo $way if [ $car -lt 0 ] ; then echo "boom" ; exit ; fi if [ $car -gt $way ] ; then echo "boom" ; exit ; fi carr=$car rest=$((140-$no-$way)) i=$(($i + 1)) j=$(($j + 5)) while [ $no -gt 0 ] ; do echo -n " " no=$(($no - 1)) done echo -n "#" while [ $way -gt 0 ] ; do echo -n " " if [ $carr -eq 0 ] ; then echo -n "O" fi way=$(($way - 1)) carr=$(($carr - 1)) done echo -n "#" while [ $rest -gt 0 ] ; do echo -n " " rest=$(($rest - 1)) done echo "" read -r -t 0.1 -n 1 -s key if [ "$key" == "z" ] ; then car=$((car - 1 )) fi if [ "$key" == "x" ] ; then car=$((car - 1 )) fi if [ "$key" == "c" ] ; then car=$((car + 1 )) fi done