b80b0f8c5f
1. Correct scaling and normalization limiter errors in floating Add/Subtract uncovered by BALGOL testing; set Single-Step instead of Stop if normalization limiter is exceeded. 2. Correct improper comparison of sign digits by CFA/CFR uncovered by BALGOL testing. 3. Change method of lamp glow update in Processor and ControlConsole to provide smoother, more realistic display. 4. Implement diagnostic trace facility in Processor; toggle on and off by double-clicking "220" logo on ControlConsole. 5. Implement temporary, experimental floatingAdd() routine in Processor that does rounding for use in BALGOL validity checking (the 220 did not round, and it is disabled in this commit). 6. Correct printer carriage control handling in CardatronOutput. 7. Improve timing for ConsolePrinter TTY "Whippet mode". 8. Implement compression of consecutive duplicate blocks in tape image files for MagTapeDrive -- see comments in source. 9. Remove inappropriate SPO selection from unit designate on PaperTapeReader panel.
The Burroughs 220 was a late-1950s, decimal, vacuum-tube, core-memory computer system. Some consider it to be the last of the major vacuum-tube computers.
The 220 was the follow-on product to the ElectroData/Burroughs Datatron 205. It was initially developed as the ElectroData Datatron 220 but renamed after Burroughs bought ElectroData in 1956. The system was initially released in 1958. It did well with both scientific and commercial applications, but being a vacuum-tube system at the beginning of the transistorized era, was only modestly successful.
The ElectroData Division of Burroughs went on to create a number of successful systems after the 220, including the B100/200/300 series, the B1700/1800/1900 series, the B2000/3000/4000/V Series, the B5000/5500, and finally the B6000/7000/A Series, which are still produced and sold today as Unisys ClearPath MCP systems.
The main goal of this project is creation of a web browser-based emulator for the 220.
A second goal is reconstruction of the Burroughs Algebraic Compiler (BALGOL), an Algol-58 compiler written for the 220 by a team from Burroughs that included Joel Erdwinn, Jack Merner, Donald Knuth, Dave Dahm, and Clark Oliphint.
The contents of this project are licensed under the MIT License.
| Related Sites | URL |
|---|---|
| Emulator hosting site | http://www.phkimpel.us/Burroughs-220/ |
| Burroughs 205/220 blog | http://datatron.blogspot.com |
| Datatron 205 site | http://www.phkimpel.us/ElectroData-205/ |
| Documents at bitsavers | http://bitsavers.org/pdf/burroughs/electrodata/220/ |
| BALGOL compiler listing | http://archive.computerhistory.org/resources/text/Knuth_Don_X4100/PDF_index/k-1-pdf/k-1-u2196-balgol220compiler.pdf |