> > System/360 was the world's first open system. > > Umm disputable. First major commercial open-ish system perhaps. But a > thumb through the fun about cables and third party hardware and the > little legal arguments seem to me to suggest it wasnt a grand "open > system" launch from day one ?
As far as the software was concerned, absolutely. White Plains' letter to Amdahl's lawyers - "IBM does not assert copyright in its systems control programming"? By the standards of the time, that made it pretty open. Leaving out Delamarters' comments about SNA - I spent my vendor career in the plug compatible industry. Few people believed it at the time - perhaps more will now - but it was possible to be TOO compatible. A data streaming channel built precisely to OEMI specs cannot attach a 3880 controller - an XA processor built according to PoP will not run VM/XA (duplicate TLB entries after common segment set). Did you know some IBM code still uses BCR 15,0? Channels were the worst. Tag handling, especially. Anyone else ever used a "Holly box"? You get into really interesting discussions when you find an IBM box that won't work with your system because it's out of specification, but it will work with an IBM system. So you wind up with the customer's lawyers - did the customer actually buy a "system (processor and DASD)" or did he buy a "processor" and some "DASD"? -- Phil Payne http://www.isham-research.com +44 7785 302 803 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
