The first computer that I recall seeing in person was an Olivetti P603 at my Dad’s office. I was about 12, early senventies. 
Seen here is a stock photo from Olivetti. My dad’s version didn’t have the drawer storage cabinet seen on the left that I recall. An electric typewriter console occupied the central operator position. On the right was a calculator type console which also served as the programming unit. On this same programming unit was a calculator size paper printer and also a magnetic strip reader/writer. Not seen in this stock photo, but below the desk level and to the right of the operator was a tape cabinet unit. One would place a tape cartridge into the unit positioning it onto the keyed motor spindle and then operate a hand lever to engage the tape into the electronics of the tape unit. Each tape contained it’s own read/write head. The tape itself was a single length endless loop configuration as pictured here. The tape cartridge dimensions were about 7″ by 6″ by 2″. 
The usable tape is visible in through the smoke gray plastic with the exception of a length that ran from this oval area to the read/write head seen at the top through the “dimpled” portion. The tape ran through a few capstans and a tensioner around the perimeter. The tape itself had 4 tracks. I have since forgotten the density of the tape, but I don’t believe each track was more than 4k roughly, for a total of approximately 16k. For a bit of fun, one could take the cartridge by itself, hand-rotate the keyed receptor on the back, and watch the tape “slowly” move through its path. As a 12 year old, I thought it was magic that the tape didn’t end up in knots. So what could you do with this whole thing? Well, it could be used as a typewriter. You could also use it for it’s calculator though I never saw it used that way myself. Then with the magnetic cards (about 2.5″ by 8 or so inches, double sided) and/or with the tape unit, one could read/write/run programs. The programs could output onto the typewriter. There was no screen. And before I forget, it weighed a “ton”. In 1979 he still had this boat anchor running parts of his office. And that year, being a computer science major and believing I could do anything with a computer, I wrote a structural heat-loss program for him on this unit. It was worse than coding in APL. Well, not really. Just to wrap up the nostalgia a bit, in summary, if one used enough of the calculator paper, one could wind it back up tightly and then pull it from its center, making a real neat paper sword for that child still in oneself – fun and no worries.
Remembering the PDP-8
The PDP-8 was a mini-computer manufactured by Digital Equipment Corporation eons ago and introduced in its earliest configuration on March 22, 1965. I was about to turn 5, and I likely had no clue what a computer was.
I was introduced to the PDP-8 in 1974 as a junior high student and wrote a few programs for a class that year. This is also about the time I noticed girls more. I wanted one, a computer, the girlfriends would have to wait another year.
Move forward 6 years to my 3rd year of college and somehow that old PDP-8 from 1974 had made its way to the local university I was attending. It was a chance encounter on my part as I took a different route through one of the campus buildings to kill some time. In some isolated room, miles from the campus computer center, it continued to hum it’s merry way. I never did find out what they were using it for, or when they got it. I still wanted one.
After college, I did not expect to see a PDP-8 machine at all. I went to work for a local software company, and, well, as luck would have it, I did have a chance to install our fuel oil billing software on a PDP-8 at an oil delivery company in 1985. I would have still wanted one – all those lights flashing and panel switches.
Move forward about 30+ years and one can procure a PDP-8 emulator and mini-replica based on the Raspberry Pi for example. I’m wondering what I will do!!