prindle@nadc.arpa (09/18/86)
Greetings, I would like to enlist the aid of this net-newsgroup community in exploring a potential hardware approach to upgrading a programming support enviroment. We are also looking at strictly software approaches, but these currently appear to have a high risk. Requirements for the hardware approach: a. A micro-programmable co-processor board which would interface directly with a high speed, state-of-the-art, computer which primarily runs a variant of Unix (preferrably System V, 4.x-BSD, or a happy marriage of the two). This board would be capable of emulating the instruction set architecture of a fairly primitive 30 bit militarized computer, specifically a Sperry (Univac) model CP-901/CP-642B. I/O channel instructions within this ISA would be converted, by the board, into interrupt requests to be honored by the main processor and the Unix system. The board would directly access a block of host computer virtual memory space (allocated by the Unix system) as the emulated computer's memory. The emulator could be multiprogrammed under control of the main processor and the Unix system: i.e. it could be stopped or started at any time by the main processor, any and all of it's registers would be readable or writable by the main processor, and the DMA memory mapping may be altered by the main processor. - or - b. A high speed, state-of-the-art, dual or multi-processor computer, running Unix as above, in which one or more of the processors could be micro- programmed to emulate the CP-901/CP-642B ISA as above, and dedicated to that task, with the remaining processor(s) running the Unix system. The goal is to run existing CP-901/CP-642B hosted support tools and some application programs with a substantial throughput improvement over a system which utilizes a physical CP-901/CP-642B computer. The bottlenecks in such a system are the physical computer resource itself (which, because it is loosly coupled to the host computer, cannot be effectively multiprogrammed), and the I/O channels which provide the only data paths in or out of the physical computer. A tightly coupled co-processor, sharing memory with the host computer and with the ability for the host computer to intervene in it's execution, eliminates these bottlenecks. Since, additionally, state-of-the-art hardware would be handling the CP-901/CP-642B emulation, as contrasted with the antiquated (and militarized) hardware of the physical computer, it is reasonable to expect at least a tenfold improvement in throughput (with a single co-processor vs. using a single physical computer). Possible candidates for the host computer are a Sun III, Dec 8600 or VAX 11/785, AT&T 3B series, or anything else which might meet the above requirements. I would appreciate any information which anyone might have about the existence of such a system or a similar system which may have been implemented; as well as any thoughts about the feasibility or potential efficiency of such a system. Please netmail any reply directly to me, as I do not subscribe to all these newsgroups. Sincerely, Frank Prindle Naval Air Development Center Warminster, Pa. 18974 Milnet: Prindle@NADC.arpa
edwards@uwmacc.UUCP (mark edwards) (09/24/86)
In article <3922@brl-smoke.ARPA> prindle@nadc.arpa writes: >Greetings, >I would like to enlist the aid of this net-newsgroup community in exploring >a potential hardware approach to upgrading a programming support enviroment. >We are also looking at strictly software approaches, but these currently >appear to have a high risk. > First I would like to state my experience with the CP901, I worked at an ASWOC as a Data System Technician (computer repairman), I have fixed several problems in it and used it to locate problems in other devices. In short I beleive I know exactly what and how it is used . The CP901 is also used on some Navy planes while the CP-642B is used on ships. Lets talk insides of these computers, can you say transistors ?? then you can say what the main logic components of the gates are for the 642B. Now can you say flat pack ?, You've got it the CP901 is uses these components to replace the transistors. Supposedly the same machine though. I am now a systems programmer/administrator for 780 based 4.2 machine. >Requirements for the hardware approach: > .... > This board would be capable of emulating the instruction set architecture > of a fairly primitive 30 bit militarized computer, specifically a Sperry > (Univac) model CP-901/CP-642B. I/O channel instructions within this ISA > would be converted, by the board, into interrupt requests to be honored by > the main processor and the Unix system. The board would directly access > a block of host computer virtual memory space (allocated by the Unix system) > as the emulated computer's memory. The emulator could be multiprogrammed > under control of the main processor and the Unix system: i.e. it could be > stopped or started at any time by the main processor, any and all of it's > registers would be readable or writable by the main processor, and the DMA > memory mapping may be altered by the main processor. > It seems this might cause problems, mainly because I/O is done differently on th CP901. It might seem to work fine in testing, but when it is ported to the CP901 problems may develop when it used in real situations. > - or - > >b. A high speed, state-of-the-art, dual or multi-processor computer, running > Unix as above, in which one or more of the processors could be micro- > programmed to emulate the CP-901/CP-642B ISA as above, and dedicated to > that task, with the remaining processor(s) running the Unix system. > I would probably go this route as long as the CP901/CP-642B were actually replaced with this machine doing the emulation of these precious dears. >..... as well as >any thoughts about the feasibility or potential efficiency of such a system. > Thoughts ? Yes plenty! The CP901/642B should be replaced, the computers along with all the antiquated periperial devices. Why beat a dead horse ?? The initial cost of replacing them will be high. But if cost are taken over a long run for maintaining the existing systems, you might even break even the first year !!!!!???? Examples The tape drives break down constantly ( have they been replaced ?). The high speed printer blows hammers about 3 a year (for the site I was at), they were $400 a crack (Gee I could've had an epson). They use Large Screen Projectors for the system, the site I was at blew at least of the projection tubes in the two years I was there, ~ $1,500 a crack. Seems like Sony or somebody makes a better one, for less. The new planes are being built all the time, and it seems the cost of building these computers will be outrageously high. The power of these machines can't be more than a 68020 chip. The cost of training programmers to write programs for these machines seems like it would be high. There are better ways of making hardware, (and cheaper). Sorry, this probably didn't belong here, but some idea of what the system does and what it actually was, wasn't apparent. mark -- {allegra, ihnp4, seismo}!uwvax!uwmacc!edwards UW-Madison, 1210 West Dayton St., Madison WI 53706