{"id":639960,"date":"2023-11-09T08:30:40","date_gmt":"2023-11-09T16:30:40","guid":{"rendered":"https:\/\/hackaday.com\/?p=639960"},"modified":"2023-11-08T21:02:15","modified_gmt":"2023-11-09T05:02:15","slug":"programming-1949-style","status":"publish","type":"post","link":"https:\/\/hackaday.com\/2023\/11\/09\/programming-1949-style\/","title":{"rendered":"Programming 1949 Style!"},"content":{"rendered":"

What was it like to program an early digital computer? [Woven Memories] wanted to know and wants you to know,<\/a> too. [Maurice Wilkes] and his team wrote a book about their EDSAC and the 18 instructions that it used. These days, you can even run an EDSAC program on a number of emulators.<\/p>\n

It is hard to realize how things we take entirely for granted had to be invented by [Wilkes] and his colleagues. The book, “The Preparation of Programs for an Electronic Digital Computers” has, among other things, the first recorded use of a software library and the first API. Even the subroutine needed inventing by [Wilkes’] student [David Wheeler], which was known for a while as the “Wheeler Jump.”<\/p>\n

Like many things in old computers, the Wheeler Jump required code to modify itself. Even indexing modes were often implemented by changing an address inside the program.<\/p>\n

While we frown on techniques like this today, you have to start somewhere. We are big fans of EDSAC<\/a> and [Dr. Wilkes] had a long and distinguished career long after EDSAC, too. The original plans for EINIAC<\/a> led to EDSAC, EDVAC, and a slew of other early machines. You can see a video of the machine with an introduction by [Wilkes] below.<\/p>\n

If you want to try your hand with the EDSAC, try your browser<\/a>. There’s also a very nice Windows emulator<\/a> that runs fine under WINE.<\/p>\n

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