IBM 1130 495

Mmm...the 1130. We had one when I was in college. It used to be the major student computer for running Fortran (Fortran II) - but that was way before I got there in 1977. By then it was sitting in a public keypunch room and was stll used by a VERY small number of engineering programing clbuttes.

I did some systems programming on it - upgraded the OS to the last version, and such. The University had modified the "OS" to do job accounting - the buttembler on it was fun to learn. I always wanted to figure out how to hook it up to a real-time clock; the thing had no concept of what time it was, which made the "job accounting" software sort of pointless.

The machine was unique in my experience in that the card reader punch could punch on cards after they were read. So the buttembler would read in a program and then think a while; you then fed in the same deck again and it would punch the object code onto the same cards that held the source - with the corresponding object being on the proper source cards!!

I mostly remember being fascinated by the Fortran II compiler. It was NOT a speed daemon. If I recall correctly it was a TWENTY-FIVE pbutt Each pbutt wrote the intermediate form back out to disk, so it took a LONG time. I distinctly remember reading the manual that described the compiler - pbutt 1 removed comments; pbutt 2 removed spaces from the program; etc. Woof.

However, it was cool to be able to write programs that actually used Fortran's "sense light" feature to turn lights on on the console, and to determine the setting of various toggle switches. Not useful (to me) but fun.

And the 1130 had a very cool APL implementation that I used a few times. The console was a Selectric printer; by putting a special APL "ball" on the typewriter you could directly enter and run APL programs. To type all of the APL characters there were several different "shift" modes on the keyboard. To indicate which shift modes were in use the computer lit up various lights on the console. By loading 0x00FF into the accumulator while waiting for user input, the right-hand register lights would light up to indicate the right hand shift key was being pressed - 0xFF00 for left shift; 0x0000 for no shift, etc.

About a dozen students played with the APL - until someone left the APL ball on the 1130 console overnight and it was stolen. No more APL...the special balls cost about $100.

Finally, one day when the university library was throwing away old books and they discarded a bunch of 360 and 370 books but kept the 1130

...Sam