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Great info as always, Ken. In the early and mid-90s, Intel was pushing their Intelligent I/O initiative (aka I2O with a subscript '2'). This had a split-driver
by quercusa 3y ago
Great info as always, Ken.
In the early and mid-90s, Intel was pushing their Intelligent I/O initiative (aka I2O with a subscript '2'). This had a split-driver model, the bottom half of which ran on an i960. It had no performance advantage and IHVs suspected it was an Intel plan to sell 960s and take away their secret-sauce advantages.
I2O didn't provide much advantage on 1-4 processor systems but provided much of the underpinnings for the NGIO and InfiniBand I/O model.
- kens 3y agoYes, interest in I2O was lukewarm for the reasons you mention. I gave I2O a brief mention in the article but didn't want to go into too much of a tangent :-) I suspect that some people at Intel really wanted to have IBM System/360 mainframe style I/O channels. There was the 8089 I/O coprocessor for the 8086. The iAPX 432 had a I/O coprocessor (43203) that worked with another microprocessor to act as an I/O channel. And then there was I2O, using an i960 as an I/O processor.
- rjsw 3y agoThe 8089 coprocessor was used in the Apricot PC [1], I had one but don't remember any documentation for the 8089 being available at the time. [1] https://en.wikipedia.org/wiki/Apricot_PC https://en.wikipedia.org/wiki/Apricot_PC
- convolvatron 3y agoit had this 'flyby dma' model for doing data transfers without going through the register file. which was pretty handy for making things like channel processors.
- rwmj 3y agoI2O was interesting because for a (short) time it was considered a threat to Linux and open systems. https://lwn.net/1998/1008/a/rms-udi.html https://lwn.net/1998/1008/a/rms-udi.html https://lwn.net/Articles/102772/ https://lwn.net/Articles/102772/ https://lwn.net/Articles/104420/ https://lwn.net/Articles/104420/
- sillywalk 3y agoThis was also the time of the Intel proposed Uniform Driver Interface