Tuesday, 20 March 2012

RPG II Continued

I blogged about the RPG II programming language previously.

Since doing so I have been conversing with two RPG programmer buddies from those days.

The first (who has asked to be referred to by the nom de plume of Hazel Nutt) reminded me that the built-in RPG cycle could be a tricky beast betimes. It did a lot for you but you had to be very familiar with it to ensure that you were always working with it rather than “agin” it.

The second (who is happy to be referred to by his real name, which is John) put me on to two things.

The first is this image of an “RPG II Debugging Template”. I mentioned these in the first article but this is what they looked like:



It is interesting to note that a flowchart for the RPG cycle is right there on the template. Again this goes back to how critical an understanding of the cycle was.

The second is this image of the first RPG II program he ever wrote:



This is obviously some kind of test program he wrote while learning the language.

Special bonus features with this program listing are:
  • The date when he compiled the program is right there on the listing: August 1971!
  • The listing was produced on a line printer (such as the 1403 I mentioned in my previous posting) and is printed on “fan-fold” paper (paper with alternate white and light green lines and perforations at the sides for tractor feeding). We called this “flowline paper” but I can’t see this term on the web so maybe it wasn’t widely used.
  • When John looked at the program again after all these years, he found something he didn't like and that he would improve if he were doing it now! I'll leave you to spot what that is for yourself!