356fb5584e
1. Alter method of writing disk sectors to IndexedDB, to avoid dragging along the entire 16KB IO Unit buffer area and unintentionally inflating host disk usage by 30-60X (ouch). This was causing Quota Exceeded errors in recent versions of Firefox. 2. Add onabort traps in B5500DiskUnit to catch QuotaExceeded errors. 3. Modify delay-deviation adjustment mechanism in B5500SetCallback to avoid oscillating between positive and negative cumulative deviations. 4. Correct tape reel angular motion in B5500MagTapeDrive, especially during reverse tape movement. 5. Fix bug with reporting memory parity error during tape I/O, should that ever occur. 6. Reset CPA Algol Glyphs option in default system configuration template. 7. Allow tools/B5500LibMaintDecoder to examine an entire .bcd tape image file instead of just the first 64KB. 8. Add USE SAVEPBT to default options in tools/COLDSTART-XIII deck. 9. Eliminate extraneous "schema update successful" alert when altering a disk subsystem configuration. 10. Commit minor corrections to source/B65ESPOL/SOURCE.alg_m from Richard Fehlinger.
The Burroughs B5500 was an innovative computer system. Released first as the B5000 in 1962 and then, with minor improvements and a new disk subsystem, re-released as the B5500 in 1964, its design was a radical departure from other commercial systems of the day. Many of the concepts that it embodied were being worked on and implemented by others around the same time, but it is difficult to think of another system that pulled so many new concepts together and made them work so well in a commercially-successful product:
* Multi-programming (multiple tasks sharing the same processor)
* Multi-processing (multiple physical processors sharing common memory and I/O)
* Automatic memory allocation and address relocation
* Automatic memory segment overlay (what we now call virtual memory)
* Use of labeled file media and automatic assignment of labeled file media to requesting programs (what we now call automatic volume recognition)
* Variable-length memory segments
* Hardware bounds checking
* Stack- and descriptor-oriented instruction set
* Unified integer/floating-point numeric format
* Management by a sophisticated operating system, the Master Control Program, or **MCP**
* Designed for and programmed exclusively in higher-level languages
The B5500 was the foundation for the Burroughs 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 B5500. A second goal is reconstruction of the source and object code for the system.
A complete software release (Mark XIII, 1971) is presently available from the hosting site below under liberal terms of a Unisys educational/hobbyist license.
The contents of this project are licensed under the MIT License.
| Related Sites | URL |
|---|---|
| Getting Started | http://www.phkimpel.us/B5500/webSite/HelpMenu.html |
| Project Blog | http://retro-b5500.blogspot.com/ |
| Emulator hosting site | http://www.phkimpel.us/B5500/ |
| Burroughs Mark XIII Software Release | http://www.phkimpel.us/B5500/webSite/SoftwareRequest.html |
| B5500 at retroComputingTasmania | http://www.retrocomputingtasmania.com/home/projects/burroughs-b5500 |
| Documents at bitsavers.org | http://bitsavers.org/pdf/burroughs/B5000_5500_5700/ |
| Release Downloads | https://drive.google.com/folderview?id=0BxqKm7v4xBswM29qUkxPTkVfYzg&usp=sharing |
| Web/email Forum | http://groups.google.com/group/retro-b5500 |
This project was originally hosted on Google Code at https://code.google.com/p/retro-b5500 and moved to GitHub in June 2015.