"I have a mind like a steel... uh... thingy." Patrick Logan's weblog.

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Friday, January 11, 2008

BASIC and the IBM 5100

Douglas Crockford's humor...

Before video terminals became cheap, Basic was usually accessed with Model 33 Teletype machines that could only print a subset of the ASCII character set. They couldn't handle lower case or some of the special characters. I called that subset Half-ASCII.
My first paid programming gig was in BASIC on an IBM 5100.

See that red switch between the tiny screen and the streaming tape drive? That determined whether you were programming in BASIC or APL!


gooddelta said...

I've always though it would be pretty awesome if there was a switch on my brain for that. I've been working in Python for the last few months and I had to switch into Ruby mode again the other day... Yeah, definitely not the same syntax.

Oh, btw, I live in Portland too. I think we could use some better weather pronto.

Patrick Logan said...

"I think we could use some better weather pronto."

We had some about 11:00am today. Where were you?

Steven Kelly said...

I think the red switch is actually the power. You can just see the labels "POWER ON" and "POWER OFF". The switch for APL/BASIC is actually missing from this picture - it was an optional feature, you could choose to buy with just APL, just BASIC, or both. The switch was in the middle above the tape drive, in the blank space in your picture. Sadly, I never had the pleasure of programming one of these - I started in BASIC on a ZX80 - so my info is from here:

Patrick Logan said...

Steven -- re: the switch. That makes sense. How much more dramatic though, for the big red switch to be the one to choose the language. 8^)

S Schwab said...

Hey I started using with one of these IBMs, at my dad's office!

Dan said...

I was in the IBM "Explorer Post" (occupational branch of boy scouts) in Rochester Minnesota from 1975-79. My dad was an engineer on several of the business computing systems there. We started out programming with punch cards and feeding them into a reader in the cold-room with raised floors that housed the System 3. We could write to the 64MB disk platters, but had to erase what we'd written before the end of the night.

It was a thrill when we were given access to two new desktop 5100's. Crashing the system was much less of a hassle since restart was easy. I learned a lot and got to really like the APL command line interface, which offered a lot more function than the Basic programming I had done via tty's at school which dialed in to a UofM computer. It was great for handling arrays and matrices.

I would love to find one of these systems for sale some day. I still have tapes and manuals.

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Portland, Oregon, United States
I'm usually writing from my favorite location on the planet, the pacific northwest of the u.s. I write for myself only and unless otherwise specified my posts here should not be taken as representing an official position of my employer. Contact me at my gee mail account, username patrickdlogan.