The GE-115 Project

 The UX challenge One of the great challenges for this project is how to represent a room sized computer on the screen. For context, the GE-115 that I first knew was in an air conditioned room about 10 m square. There was a raised floor to allow for cabling to run underneath, so the door opened to a ramp that went up about a foot to the raised floor. Turning right at the top of the ramp, you would see the computer laid out in a U-shape (the big "U"), and you would be standing at the open spot in the "U". On the left was the line printer. Beside the line printer was the CPU main cabinet, which was also U-shaped (the small "U") with two cabinets extending back (to the left from this perspective). There was also an extension from the CPU to the right, which begins the bottom of the big "U". It was work table height and was flat on top so that you could organize cards, manuals and other things necessary to operate the computer. This work cabinet incl...

Assembly Programming System - APS In order to help with the testing of the simulator, I was writing more and more binary code. The next logical step was to create an APS assembler. The assembler takes code written with mnemonics and simple arithmetic phrases and converts it to the binary code that will run on the machine (simulator). Of course, every new idea introduced challenges the framework and assumptions of the simulator. On the real computer, you would boot the DOS operating system from a simple load card, and then DOS would take over. DOS included the BIOS (Basic Input Output System) and the mechanism for loading system programs. APS was a system program which processed a text file, normally on punch cards. APS would produce a work file in the "free space" of the system disk. This was a convention share by all of the compilers. Then, you would "insert" the program into the program file on the system disk using a command API (Assembled Program Insert). Only t...

The GE-115 Project When I was in high school in Barrie Ontario Canada in 1968, they installed a new computer called a GE-115. It was a room-sized beast which required several tons of air conditioning. It had an internal cycle time of about 7.5 milliseconds, so it could execute about 100 instructions per second, compared to current standards of several billion instructions per second. It had 12K of internal core memory, compared to my phone which has 32 GB (2 thousand versus 32 billion). I came to love this computer. I learned everything I could about it, including how to program in machine code using a language they called Basic APS (Application Programming System). By the end of high school in 1973, I was a local expert. We met with another high school in Pembrooke Ontario, and I learned from them. Then I went to the University of Waterloo to take Mathematics, majoring in Computer Science. In my first co-op work term, I was hired by Honeywell (who had acquired the computer division of...