So much has happened

 It has been a while since I posted. Such is life!

This fall I have been poking around with the simulator, adding new features and testing old ones to make sure they still worked. In the meanwhile, some really interesting developments happened.

The Computer History Museum digitized two new manuals for the GE-115: The GE-115 Users Guide Reference Manual and Programming the GE-115. I am immensely grateful to everyone at CHM for making this happen.

These manuals had a tremendous amount of information in them. The Systems Manual (1965) had a more explicit definition of the APS assembly language, including assembler directives and storage declarations. This manual also clarified some information about binary and decimal arithmetic, particularly around how calculations proceeded when the operands are of different length. It took about a month to fix the simulator up to the point of accurately reflecting the new reality outlined in the Systems Manual. There were a number of interesting revelations about instructions such as add binary and add decimal which use the right hand address of the operands, rather than the more predominant left hand addressing. The manual also had a detailed layout of how the peripheral control unit accessed the physical devices.

The GE-115 User's Guide Reference manual was published in 1966, and outlines the APS system for the Gamma 115. The phrase Gamma 115 is basically treated with whiteout throughout the typewritten document and replaced with GE-115 ... a shorter phrase in a longer space. However, they missed a couple of spots, so the mystery phrase Gamma 115 was revealed!!

Programming the GE-115 is a self paced instruction course. An early version of self instruction, the manual is written in such a way that the answers to the exercises are in a panel on the right side of the page, which can be obscured by a piece of paper as you read through. This manual also had some insights into some of the workings oh the OS and APS. 

The APS language outlined in this manual is much stricter than the APS I used in 1970. For example, decimal numbers had to be 3 digits long, so 1 was 001, etc. Later versions of APS were more forgiving.

The manual also includes descriptions of the subroutines used for input and output, including YLBSC. These subroutines were not part of the operating system, but needed to be added in source form at the end of the programmers. YLBSC is the print, card read, and card punch utility. It was replaced by *LBSS in the DOS operation system. So this indicates that the manual was used with the Card Operating System COS rather than tape or disc operating system.

Also, I was in touch with the National Museum of Science and Technology in Ottawa. I was able to confirm that they have the actual computer from my high school in their warehouse! In looking at the supporting documents, I ran across the name Tim Crawford, who was the Head of Data Processing for the board at the time of the donation. Tim was one of my teachers and mentors and it was a nice memory to see his name again.

In a couple of weeks, I will be meeting with one of the curators of the museum. We will not be looking at all of the crates of computer components, as that is not particularly productive. However, there are several manuals, listings and card deck artifacts that we will be looking at. I am very excited about what I might see!!

The next challenge for me will be putting the simulator online. I am trying to decide right now about what the best technology and platform would be for the web site. I believe that I can use a wrapper to take the various libraries that I have written and access them from code in the website. This will be the big project for 2025.

Jim 

Here are the links to the new manuals at the Computer History Museum:

GE-115 User's Guide Reference Manual https://www.computerhistory.org/collections/catalog/102638629

Programming the GE-115 https://www.computerhistory.org/collections/catalog/102775993


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