[email protected] (John McKown) writes: > Look at the current "System i". It really looks a lot like what has been > discussed here. It has, theoretically, a 128 bit virtual addresses. > Everything is an object. It has the single level storage so there aren't > really any "disk files" as such. And once an address has been associated > with an object, that address will _never_ again be used for some other > object. So when an object is freed, its address becomes unavailable. Thus > it is impossible to access a freed object or accidentally use an old > address to access a different object.
re: http://www.garlic.com/~lynn/2014c.html#71 assembler http://www.garlic.com/~lynn/2014c.html#74 assembler folklore is that when future system failed, several people retreated to rochester and did (a "simplified" as) the s/38, capability, single level store, etc. http://www.garlic.com/~lynn/submain.html#futuresys One of the simplification was treating all disk as common allocation pool with scatter allocation. As a result, the complete infrastructure had to backed up as single operation ... and any single disk failure resulted in having to make a complete restore of everything ... restore after a single disk failure could take a day or more. As a result, s/38 was early adopter of RAID ... patent issued to San Jose disk engineer late 70s. http://en.wikipedia.org/wiki/RAID AS/400 was follow-on to combination of s/38 & s/36 ... single-level store retained ... http://en.wikipedia.org/wiki/IBM_System_i but capability-based address was dropped. http://en.wikipedia.org/wiki/IBM_System_i#History circa 1980 there was an effort to replace large number of internal microprocessors with 801/risc Iliad chips (4361/4381 followon to 4331/4341, as/400, lots of controller microprocessors, etc) ... for various reasons ... those efforts floundered and they did continued business as usual with customer cisc chips. later in the 90s, the as/400 was part of the AIM (apple, ibm, motorola) group doing power/pc (single chip 801/risc) activity and finally moved to 801/risc (now system i). past posts 801, risc, illiad, romp, rios, power, power/pc, etc http://www.garlic.com/~lynn/subtopic.html#801 as an aside, after the failure of the 1980 effort to move to 801/risc ... some number of the chip engineers left and show up on risc projects at other vendors. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
