Identify this computer

Back in about 1977 or 1978, I programmed my first computer. It was something that a guest brought into our school. Years went by and I kind of forgot about the thing, but periodically it resurfaces in my mind. Every time I’ve searched the internet I haven’t been able to figure out what it was. I’m hoping someone here can identify it.

Here is what I remember. It was sitting on an audio/visual cart (one of those carts that they put projectors and such on), so it wasn’t terribly large. It was boxy, I’m thinking about 18 inches by 14 inches or so, and maybe 12 inches or so high, and kinda greyish in color. There were 3 ways of programming it. One was punch cards, which went in either on the top near one side, or on the side near the top. On the opposite side you could stick in a magnetic card similar to a credit card, and I remember that one credit card type thing could hold several punch cards worth of data. Somewhere on the thing was a keypad, just a numeric sort of thing with a few extra buttons, nothing like a modern keyboard. The output was a paper strip, like from a cash register.

It looked like a professionally built machine, not something that a hobbyist may have thrown together, so I think it was a mass produced model of some sort.

Anyone?

The HP 9815A was around at ~that time. It came with a magnetic card reader. I never saw a punch card reader for it, but there were several versions produced.

Nope, that’s not it. Too short (think boxy, like a photocopier), way too many keys, and no punch card reader.