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