Welcome to the Datatron 205 and 220 Blog

This blog is a companion to T J Sawyer's Web Page that outlines the history of the Burroughs Datatron 205 and Paul Kimpel's incredible 205 and 220 emulators. Please visit those sites and return here to post any comments.

Saturday, April 11, 2015

Moving to GitHub

As mentioned in the last post, Google is in the process of shutting down the open-source project hosting service where to date the retro-205 emulator has been maintained. We have therefore moved the project from Google Code to another popular open-source hosting site, GitHub. The new URL for the project site is:


The Google Code site will remain available for a while, but will no longer be updated with new emulator development. Google plans to shut down the service completely in early 2016. All further emulator development will be posted to the new GitHub site.

Note that this move affects only the open-source project site. This blog, the hosting site, and Tom Sawyer's 205 web site are unaffected and remain at their former URLs.

References to the project site in previous blogs have been updated to refer to the new site. For those of you interested in obtaining a copy of the source code, viewing the commit history, or forking the emulator, GitHub offers some improved capabilities:
  • You can download a zip file of the latest version of the source code by clicking the Download ZIP button on the project's home page at the GitHub link above.
  • You can clone the project using a Git command similar to the following:
    git clone https://github.com/pkimpel/retro-205 retro-205
  • Although the GitHub project is based on the Git source code repository, GitHub also allows you to use Subversion clients to check out a copy of the code, e.g.,
    svn checkout https://github.com/pkimpel/retro-205/trunk retro-205
  • [Update 2015-0511] You can create new entries in the project's issue tracker to report bugs or other problems if you have a GitHub account. It's free to sign up for such an account. After obtaining an account, go to the project site and click the "Issues" tab on the right side of the home page.

Emulator Version 0.04c Released


Coincident with the project's move to GitHub, emulator version 0.04c has been released as is now available from the hosting site. This is a very minor update:
  • The home page has been updated to redirect the link for the project site to GitHib.
  • The HTML5 application cache feature has been reinstated for the emulator. In browsers supporting this feature, it stores the emulator locally within the browser and allows it to run when there is no network connection to the hosting site. Activation of this feature is automatic.
  • [Update 2015-04-13] The Cardatron line printer has been moved from unit number 2 to unit number 3. This was actually a change introduced in version 0.04b, which was not publicly released. The card punch remains as output unit 1 and the card reader as input unit 1. Eventually we hope to implement a way for the unit numbers to be user-configurable.
Further work on the emulator is presently focused on implementation of magnetic tape units and transcription of the assembly language code for Donald Knuth's Algol-58 compiler from a scanned listing. We estimate the next major release will occur in June 2015.