Aucbvax.1785 fa.info-cpm utzoo!duke!decvax!ucbvax!AFITGORDON@BBNB Tue Jun 16 22:45:31 1981 Re: CPM vs **NIX--Re: More on the CP/M vs Unix talk In response to the message sent 16 Jun 1981 1855-PDT from Ime-Tecom@OFFICE-2 Hello, Everyone, Before I get started, I want to say that I think this exchange is FANTASTIC! I'm learning much from it (and doing much research because of it), and such a wide diversity of views is enlightening, entertaining, and enjoyable. I hope the following comments are useful, and I hope I'm not deviating too much from the original question. As I view it, the original question concerned the creation of a microcomputer-based office automation system and which OS should host it. Richard Conn -------- Comments Follow -------- Part 1 First, I wish to take issue to the extreme with Dave Farber's comments; I disagree with them almost completely (sorry, Dave, and please don't take offense, but I feel the following data speaks for itself)! I refer to Dave's message (Farber@Udel-EE, sent 16 Jun 81 at 8:58 EDT). In his first paragraph, Dave states that CP/M was created for processors with small memory (8080's, <=64K), single processor configurations, and that "Systems based on such ... assumptions ... have had severe difficulties adapting as ... [memory size grew] ... and ... [multiprocessor configurations were created]." I agree with his statement about CP/M, but I disagree with the material I quoted and view it an an unsubstantiated value judgement. Dave goes on to imply that CP/M is "old fashioned" and should be discredited because of its age. From my point of view (and this is how I believe he intended us to believe), Dave is saying that UNIX is newer than CP/M and was intended from the beginning to run on "larger mainframes". This is not true! When I first began work on my Master's at U of Illinois in 76, I heard about UNIX long before I heard about CP/M. This memory prompted me to do a little research, and the following summarizes the results of this evenings research -- UNIX CP/M o 1st Version: 1969 o 1st Version (1.0?): 1974 o 1st machine implemented on: PDP 7 & PDP 9 Intel Intellec? (8080) o 2nd Version: 1971 o 2nd Version (2.0): 1979 o 2nd machines implemented on: PDP 11/20 Many 8080's, Z80's 1st released 1970 1 processor 32K words max memory 16-bit words o Upward-compatable OS Family: Compatability lies is in Excellent upward-compatability C source code; OS "hooks" on the binary (OS "hooks") level; at binary level show no ASM assembler and PL/M source inter-version compatability compatability maintained at all! (this is inferred, does anyone dispute with data?) Compatability Synopsis: -None- CP/M 1.3 -> CP/M 1.4 -> CP/M 2.0 -> CP/M 2.1 -> CP/M 2.2 -> MP/M 1.0 -> MP/M 1.1 -> CP/NET (MP/M-based) [CP/M 3.0 and CP/M-86 - no data] o Number of systems running OS: "over 600 installations" over 200,000 installations (1978) on HW costing (1979) on HW costing "as little as $40,000" as little as $3,000 (my experience) The above information came from the following sources: (A) UNIX info from (A1) "The UNIX Time-Sharing System" (Apr 78), The Bell System Technical Journal, JUL-AUG 78, Vol 57, No 6, Part 2, ISSN0005- 8580 and [for PDP 11/20 info] (A2) "PDP 11/20, 15, R20 Processor Handbook", Digital Equipment Corporation, 1971; (B) CP/M info from "CP/M: A Family of 8- and 16-Bit Operating Systems", Byte Mag, June 81, Pg 216, by Gary Kildall [creator of CP/M]. From the above, the following information is not documentably substantiated: (1) binary-level inter-version UNIX compatability [these statements were made based on personal conversations], (2) the 200,000 installation figure for CP/M [this statement made based on an ad from Digital Research that I couldn't find this evening; I have heard later rumors as high as 400,000+!, but these are almost totally undocumented], and (3) the CP/M $3,000 cost [based on personal experience with 5 1/4" floppies and 32K bytes memory]. The compatability I mentioned above should be stressed on the binary level! To my knowledge (based on conversation), the historical versions of UNIX do not support the same hooks (binary level), so binary written on one version cannot be transferred to another! With CP/M, however, I have written programs in assembly language which have run without modification (!!!) on CP/M 1.3, CP/M 1.4, CP/M 2.0, CP/M 2.2, MP/M, 1.0, and MP/M 1.1!!!! And the machines that this CP/M program ran on were Intel Multibus, IEEE S-100 (Z80), Cromemco S-100 (Z80), Ithaca Intersystems IEEE S-100 (Z80), and Electronic Control Technology IEEE S-100 (California Computer Systems Z80). UNIX, on the other hand, runs only on PDP 7, PDP 9, PDP 11, and VAX 11 (All DEC UNIBUS except for the VAX with is DEC MASSBUS and UNIBUS). Another complaint was the lack of multiprogramming and multiprocessing capabilities with CP/M. To dispell these comments, MP/M 1.1 can support up to 16 users, each having 64K (48K work area) of memory and running on a single processor system. CP/NET is a network support system which runs under MP/M (required for host) and CP/M or MP/M (remotes) which allows sharing of common data and programs on each of the satellites (separate processors with their own terminals, printers, and disks) with the host (also with its own terminals, printers, and disks). AND THIS IS ALL UPWARD COMPATABLE WITH CP/M 2.2, WHICH MEANS THAT PROGRAMS WRITTEN ON CP/M 2.2 CAN BE MADE (SOMETIMES WITH NO MODIFICATION AT ALL!) TO RUN ON MP/M AND CP/NET!!! Now that I have issued all of these pro-CP/M arguments, I wish to conclude by saying that -- 1. Just because software has been around for some time does not mean its value is degraded with time; software is good or bad in the eyes of the user only, regardless of how long ago it was written 2. Although I sound pro-CP/M, I do not view it as a panacea! My experience with UNIX has been pleasurable, and I feel it has many concepts which are interesting and of value (re my first message). 3. The OS, again, is just the RESOURCE MANAGER of the computer system, and I feel that the real value of the system lies in the tools (editors, languages, DBMS's, debuggers, etc) that run under the OS. Transporability of software under CP/M is on the binary AND source level, while transportability under UNIX is ONLY on the source level (Is this correct?), usually in C. If the user selects UNIX, he could very well be burning his bridges to the excellent CP/M programs marketed in binary (like MDBS, Word Star) while he who selects CP/M is open to the CP/M programs marketed in binary AND still has the UNIX world open since C compilers run under CP/M and UNIX transportable programs are written in C (true?). If you could find a UNIX-like OS with can also run CP/M binaries (OS-1 claims to do this), I feel that this would be the ultimate solution to our discussions. Richard Conn ------- Brought to you by Super Global Mega Corp .com