On 12 Aug 2015, at 11:24 pm, Paul Koning <paulkoning at comcast.net> wrote: I did find a copy of the B6500 ESPOL compiler online recently.

Did Algol come after the hardware? I always thought of the hardware as having been customized for their Algol, but admittedly I don?t actually know which is chicken and which is egg.

On 13 Aug 2015, at 4:41 am, Paul Koning <paulkoning at comcast.net> wrote: I found this out when I tried to write a program that reads foreign format tapes, in particular past tape marks. Algol can?t do that ? either that, or the consultants couldn?t figure out how.

I started looking at other languages, but when I started asking questions about DCALGOL I got a whole lot of pushback from the system staff. They viewed questions like that with extreme suspicion.

In addition, B5500/B5700 Mark XIII and B5500/B5700 MARK XV.3 release tapes can be found online. UNISYS released these under the "UNISYS MCP MARK XIII SOFTWARE EDUCATIONAL/HOBBYIST LICENSE AGREEMENT" in 2012, having been approached by the owner of the tapes. At least Mark XIII is available on Paul Kimpel's web site. PLEASE NOTE THE LICENSE, which was arranged through Unisys (Bob Supnik was the contact at the time, but he has since retired from Unisys, according to what I see on LinkedIn). The history of how that happened is on the web page, below, along with links to download the tape images. http://www.phkimpel.us/B5500/webSite/SoftwareRequest.html A Google for "MARK XV.3 BURROUGHS" will turn up the MARK XV.3 tapes as well. ;) I am not aware of a similar license document for that set, but I suggest it should be considered to exist under at least the same restrictions ("solely for non-commercial educational or hobbyist purposes"). Anyway, I looked at my listing of the MARK XIII tape SYMBOL1 7 Track BCD tape image, and it has ESPOL source. The ESPOL Compiler, version MARK XIII.0 starts at File 18, dated July 15, 1971. I'd expect it to be present on MARK XV.3 as well, of course. Also on the MARK XIII SYMBOL1 tape (Looking at the directory in file 2, from my same listing) MCP INTRINS ALGOL BASIC COBOL DC1000 FORTRAN NDL TSPOL XALGOL I don't seem to have ever made a listing of what is on tape SYMBOL2. How odd. But, not to worry, a listing of what is on that tape is available at: http://www.phkimpel.us/B5500/webSite/TapeImage-SYMBOL2.html JRJ On 8/12/2015 12:39 PM, Nigel Williams wrote: wrote: https://github.com/pkimpel/retro-b5500/tree/master/source having been customized for their Algol, but admittedly I don?t actually know which is chicken and which is egg. designed as an ALGOL machine and Burroughs had the idea that only compilers would generate machine code, so they made the B5000 compiler friendly, and the system would have an OS to manage resources, so it was designed around drum/disk being an intrinsic part of the system.

On 13 Aug 2015, at 1:04 pm, Toby Thain <toby at telegraphics.com.au> wrote: For more on this, see "Classic Operating Systems," Per Brinch Hansen, which reprints the paper "Operating System for the B 5000", Clark Oliphint (1964). "Two of the major B 5000 design objectives were (1) that all programming was to be done in ALGOL and COBOL, and (2) that the operation of the system was to be directed by a Master Control Program (MCP) which would relieve the operator and---especially---the programmer of virtually all the inefficient and error-causing details of peripheral unit designation, memory area assignment, and so on. The simultaneous and coordinated design of the computer and the programming system has produced a hardware-software system so well integrated that all B 5000 users employ the standard programming system (with minor modifications for special applications in a few cases). It has been the experience of B 5000 users that the exclusive use of compiler languages in programming gives advantages in documentation, program preparation, and debugging which cannot be over emphasized. ..."