[cctalk] Re: mainframe vs mini

I'm still trying to get a good answer to "when did the first commercial (as opposed to one-off lab) computer appear that had interrupts as a standard feature?" It looks like there was the IBM 704, in 1958, with interrupts but some documentation made me think it was an optional feature. The other machine from 1958 I can think of is the Electrologica X1. That is the machine that confronted Dijkstra with the need to develop new theory to deal with the non-sequential behavior of machines with interrupts, and his Ph.D. thesis was the result. The X1 is also interesting in that it has what much later would be called a BIOS -- a ROM-resident software library that included I/O services including dealing with interrupts, an assembler/loader, and an operator interface. Dijkstra wrote that, and the source code is in an appendix of his thesis.