John Daines LEO III Programming and Operating Utilities
An important utility managed program changes with the Version Control utility implemented in the Intercode Translator. A programme had a 5 digit version number that was incremented by 1 each time the program was amended. See Volume III, section15 at http://sw.ccs.bcs.org/leo/LeoIC6-17.htm#s15 15.1, 15.2 and 15.3 last paragraph “New Issue Number” Each line of code was numbered by the Translation when the program was first created and, if it had been amended, the program version number of the amendment was printed next to it. All this was built in. There was a program trials facility built into the Translator see volume III section 16 at http://sw.ccs.bcs.org/leo/LeoIC6-17.htm#s16
There were standard sort utilities 07003 (3 tape sort) and 07003 (4 tape sort). They were string sorts where the strings were created on two work tapes from the input tape in the first pass and subsequently merged, utilising the hardware merge instruction, until the final two strings were merged onto the output file.
Printing could either be directly to a line printer, which would restrict its use by other programs, or by sending each print line to a magnetic tape file with a header, that said what type of report it was, together with any paper movement controls. Thus a program could effectively output to any number of “printers”. The standard print program utility 06060 would subsequently read the magnetic tape, printing all lines of a report type on each pass. Lines of print were assembled by a table driven hardware instruction that selected data as required, changing formats and inserting £ signs as required. All this was cross checked by the Translator.
There were also utilities to manage program libraries, copy and compare magnetic tape files and print the contents of magnetic tapes and main store. See volume V.
More importantly, there is an extensive piece of work by Ken Kemp, who was in charge of Leo systems and programming at the English Electric-Leo Service Bureau in Bristol in the mid to late 1960’s. At http://sw.ccs.bcs.org/leo/Manuals.htm , the main index to the manuals, there is a pointer to Recollections of a Leo III user, which is at http://sw.ccs.bcs.org/leo/KenK.htm
