??! *.7~; .i CP/M: A Family of 8- .k&9 " G~, and 16-Bit-1 ,- P.Operating ." Systems -kvaka .& ' Dr ',% 4 ! I;- POB 579 .t 801 Lighthouse Ave +: Pacific Grove CA 93950 I'

This article is about microproces- low-cost storage medium was paper management can be separated from ere they came tape (used in applications ranging the I/O (input/output) system (which t they are, and what from program development to word is not required in many applications). to be. Where they came processing). At a cost of $5, a floppy Real-time facilities allow the execu- , what they are today disk held as much data as two hun- tion of interactive processes accord- t they will become is, dred feet of paper tape, and a disk ing to priority, and their addition or tion of technology, drive retailed for only $500-an un- deletion in a simple fashion. This iction" speculation. beatable combination. Memory, pro- results in a custom is an operating system devel- cessor, and floppydisk technology designed to solve a particular prob- . But as improved, and by the mid-1970s, a lem. In contrast to timesharing, real- hanged, CP/M and floppy-based could be pur- time operating systems have minimal related programming tools chased for about one quarter of a pro- "interrupt windows" in which exter- olved into a family of portable op- grammer's annual salary. Quite nal interrupts are disabled. Real-time ages, and ap- simply, it was no longer necessary to operating systems such as the computer resources. RMX and National Starplex packages omputer resources Since that time, microprocessors provide this level of support. d dramatically with the in- have been applied to a variety of The emerging interest in local net- of microprocessors. Three works poses a new challenge to de- ts have precipitated a rev- signers of operating systems. Recent- on in computing: hand-threaded ly, Intel, DEC (Digital Equipment memory has been replaced by The 1 version of Corporation), and Xerox formed an ced semiconductor mem- CP/M ISbasically the alliance to promote Ethernet, a pack- ory; microprocessors have become same as the &bit - et-switchingnetwork intended topro- plentiful; and IBM decided that the vide point-to-point data transfer in an punched card is obsolete. Low-cost sionf the addition office environment. (In a packet- memory and processors have reduced of memow manage- switching network, data from several the cost of computer systems to a few ment and enhance- slow-speed sources, such as user ter- hundred dollars, but IBM's speci- merits to the file minals, is collected over local lines by fication of the standard a single network node, which then has made the small computer system system. periodically transmits the data to its yseful. destination at a much higher speed, in ., In the early days of the 8080 micro- groups called packets.) In terms of ' -' Fj ,,$ processor, a small company called computing needs beyond replacement evolution and potential, Ethernet is j-cltbb:- Shugart Associates was taking shape of low-end minicomputers. Due to today what floppy disks were a:-+ , up the street from Intel. Shugart As- applications such as machine-tool decade ago. This inexpensive officej;i t{i; sociates, along with a number of movement and sensing, data acquisi- network performs such tasks as thewTfi r-2 other companies, viewed the floppy tion, and communications, current transfer of a form letter from data f--I disk as than a punched card re- interest lies in real-time control. In a storage at one location to a rnernory;~ii~~ placement: at that time the primary real-time operating system, process typewriter in another part of the &' -% ...... logic -.-- '1 &d:':'ie*iepr:@-;r!I. .,- fhe-I&i&tion, dectranics accu&(e: -.g&r&t&h-' &i&@,&; . ::

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,.-..nolO@&T mornenhrti Pbas ob.v.iouj.-..-':. :.&t&es;...... ,.riie-&&ann &@f+turi4ig. - .;-..suptiqrt,,s$&m.linguage~, qp'clrit: -,, . i .::M~~To$@~o~s ...... u@.:g:dif~~t-~.d: ::-::::::me~al-pgrpose . fun-ction -.~fii$i?; ...... appl.i&it@n...~tii;-::...... :-.iig.&&?mi,:.;ipid_ > ... " ...... - . . gy&es. Thise. tools. form ...... of.' our -:. pattern-.:.of [email protected],tI: put a:v.hi~~:x djt:,.iltq.: input, pins, .. $ngil~efi~g8-'~&tf&as~~~~i;;?:..ydefine...... ~&&~'~i~~t~$':~f-' by.$k.jh&i-: @+M pyy&i&&≷:;;ipr,.-...... , - ' . ... .- ' - ' ...... @g 7?7 ifi a'r&ed: .. - ~ersio,n...... of 'the ~~t~@<,~~e~~:6&.-&~.-:~&0~~set, of pficati&. . -softwwe, : ' - - ...... : .o$ginaJ ~f:Wrj&t.::Brof~er~:':.:.~i~~~~-.:.-... mq&$ty...... -. : .. :...... :....:...... - .- .... \ ...... -...... -~-:;pi~;i'iid.ihe~&julf,.f(x),...... , ...... fibb, :[email protected]&&F?rQO&Sg~p&:b .c&&";-'.' on,-,the')&tp.t?ut;p:f&&;: Many.-. ' - ...... -...... - ...... '...... ': 'appe&s .....- ...... ,. ." ...... -......

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8 June 1981 (n BBYIE Publicction~Inc Clroie 194 on inquiry card. building. When modifications are operating systems, but the most ex- facilities, but it excludes scientific fea- completed, the letter is typed locally citing new operating system techno- tures such as a complete transcen- or sent to a laser (or other) printer logy will develop around emerging dental-function library. that is a shared network resource. network hardware. In contrast to system languages Most timesharing systems handle a that run on a given machine, these network through simple file transfers Application Languages application languages would ideally between the machines (nodes) in the Application languages form the top contain no machinedependent fea- net, but real refinements occur when level of support for application pro- tures. An application language is the operating system itself is distrib- gramming. How does this level of either poorly designed or ill-suited for uted among the nodes. File access is language differ from other language a particular problem if the program- provided by one server node, while a levels? First and foremost, an applica- mer is forced to use extra-lingual con- computing function is performed by tion language contains the operations structs to access lower-level functions another. To the user, a requester and data types suitable for expressing of the operating system or machine. node appears as a powerful comput- programs in a particular problem en- The language must be a standard, ing facility, even though it may con- vironment. (FORmula without the necessity for various sist of only a local microprocessor, TRANslation), for example, was de- locally defined language extensions. a console, and a limited amount of signed in the late 1950s for scientific An extended standard language is of memory. applications; FORTRAN programs, limited value since the extensions are What refinements have been made therefore, consist primarily of alge- unlikely to exist in other implementa- to operating systems? Our models braic expressions operating upon tions. have been simplified; we understand binary floating-point numbers ex- The evolution of PL/I (Program- primitive operations required for pressed in scientific notation. How- ming Language/One) provides a reliable process synchronization in ever, FORTRAN contains only primi- good example of refinement in ap- real-time systems, and the human- tive file-access facilities and no plication languages. PL/I is not a new oriented interface in interactive decimal arithmetic, making it unsuit- invention: rather, it was defined by a subsystems has been improved. We able for commercial data processing. committee of IBM users in 1960 as a will, no doubt, continue to refine our COBOL (Common Business Ori- combination of ALGOL (ALGO- models for timesharing and real-time ented Language) has the commercial rifhmic Language), FORTRAN, and COBOL, with a liberal sprinkling of new facilities. ALGOL's principal contribution was block structure and nested constructs, while FORTRAN BUS-TO-BUS COMMUNICATION contributed scientific processing and COBOL added commercial facilities. This combination produced a large, unwieldy language with twists and nuances that can trap the unwary . Nevertheless, PL/I was quite comprehensive, and it served as the basis for uncounted numbers of application programs on large - tems. One noted use of PL/I was in the implementation of the Multics op- Cromemco North Star erating System at MIT under Project MAC. In 1976, an ANSI (American Na- Inexpensive S-100 can now communicate with the tional Standards Institute) committee IEEE-488 instrumentation bus. The P&T-488meets the IEEE-488 ~roduceda standard language defini- 1980 standard for controller, listener, and talker. tion for PL/I. The standard is an im- "Canned" allows simple communication with the plementation guide for 488 bus from Basic, Pascal, and other high level languages. writers, and it precisely defines the Special features include an interactive busmonitor program form and function of each PL/I state- and a functional self-test program. ment. Aware that PL/I was too large Price for (1) P&T-488 with software, assembled and tested: $450 (domestic price) FOB GMeta. CA. and complicated, the committee pro- 11 CP/M is a registered trademark of Dig~talResearch. duced a smaller version for minicorn* puters, called Subset G. This new lani PICKLES & TROUT guage excluded the redundancies and P. 0.BOX 1206, GOLETA, CA 931 16, (805) 685-4641 pitfalls of full PL/I but retained the

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2U1 June l98l @ BYIT Publications Inc Circle 293.on inquiry card. useful application programming fea- tures. Recently approved by ANSI, systembwea' . I-- Subset G has given new life to PL/I, A . sgstem -language- is & kigh- with manufacturer support for the &el rriirchine-clepende~.h6iram- Data General Eclipse and MV/8000 ming knguge used to @pl.msnt computers, Prime computers, Wang wCd1.ed ~systetv Softw~re," ;ti- machines, and DEC's popular VAX cluditzg = operatirig systems, - tgxi computer. editors, _ debvggers, ititkrpkte-rs, Strangely, the refinements found in and csmpilers. lfi the iiarly-daysIaj

application languages follow those of computing, ' virtually a11 system hardware and operating systems. software wa. iinple&&d in as- L Large, cumbersome languages have sembly language. Qure: revolutiovi- lntertec Superbrain SPECIALS been rejected in favor of simple, Spar- ary machine, the Burrough 64K Ram, List $3495...... $2595 tan programming systems that are E550&, used..-a %ati?nt - oj 64K Quad, List $3995...... $2995 consistent in their design. The result- ALCOL-6Q LZS- iis only system- Northstar ing languages are easier to imple- pragramming tool and qvp~aredirl Horizon 132K DD Llst $2695. .. $1989* ment, simpler to comprehend, and the early i4'6.h.. The mchine.w& a Horizon I OD L~st$2995...... $2245" allow straightforward program com- cornmmiat succee aget the Horizon 2 32DD List $3095 ..... $2289* IntersystemDPS-1 L1s1$1749. .. $1495" position. other major mqinframes, - pzrqping Call for latesr NorrhSrar and tkbt--as&mbh . were no longer Intersystem Prices PL/M: The Base for CP/M necessary. Many succe6sficJ sm In 1972, MAA ( tem langzkges foliotned Bur- Applications Associates), the pre- roughs' .ALGOL, including- fke C decessor of Digital Research, con- language, produced at Bell Lab- sulted with the small, aspiring micro- orcjtorks in the late 1960~~qhich processor division of a semiconductor served as the bas6 for-the .ItNiX memory company called Intel Cor- operating system. Cromemco 2-2H, ~1st$9995 . . $7945 poration. MAA defined and imple- A system- langtitzge, by defini- System 2.64K Llst$4695...... $3749 mented a new systems-programming tion, matches th? arckitechrrk of q Svsrem 3,64K, L~sr$7995 ...... $6395 language, called PL/M (Program- part3cular machine or rlw'af-ma- Disk Systems ming Language for Microcomputers), chines; all facilities of the karhine Thinker Toys DISCUS2D ...... $939 to assembly-language pro- Dual Discus 20 ...... : ... $1559 are accessible in the l$n&uage, and Dlscus2 + 2, L~sr$1549...... $1259 gramming for Intel's 8-bit micropro- the Iangyge contairzs no non- M26 Hard Disk, List $4995...... $3949 cessor. PL/M is a refinement of the trivial extensions be~nd%he Printers (5 Terminals XPL compiler-writing language which machine capabilities, The berrefit is Paper Tiger I DS-445 ...... $649 is, in turn, a language with elements with graphic opton ...... $719 thgt a compiler for the system. lan- Centronics 730-1, L~st$795...... $549 from Burroughs Corporation's ALGOL guage is- easy to implem~tma 737-1, List$995...... $769 and the full set of PL/I. transport +om maek&c?..to mi 704-9 180 cps ...... $1495 The first substantial program writ- chine, as !ong as-the architechrlce oj 703-9 180 CPS ...... $1 569 TI 810, List $1895...... $1489 ten by MAA using PL/M was a each mchine is sInii'lar, FtqthSPr, a NEC SPINWRITER 5530...... $2395 paper-tape editor for the 8008 micro- system- fanguagg.requires Mekn- NEC SPINWRITER 5515...... $2395 processor, which later became the time support since applim'on fiih Diablo 630 List $271 1 ...... $2399 CP/M program editor, called ED. Intertube Ill List $895...... $729 Eities, such as extensive f/Q (input/ ZenithZ-19 ...... $719 PL/M is a commercial success for output) processing; QFe hot gener* Televideo 912C ...... $679 Intel Corporation and, although ally -embodied in the ta&tageee - 920C ...... $799 licensing policies have limited its gen- 950.. .. : ...... $999 Refinements in system fangwges Hazeltine 1420...... $789 eral accessibility, it has become the aw- made b~ty increasing their 1500 ...... $845 standard language of the Intel micro- kbflify. Their acceptance .& re- Soroc 120 List $995...... $689 processor world, with implement- IQ135...... $719 placemmts f~ kwrbly languages 140 ...... $994 ations for the 8080, 8085, and 8086 is encouraging. Today, .one man families. publicly admit that -.system-soft- MAA also proposed a companion ware b implemented in a high-level operating system, called CP/M (Con- *languagewithout -implying that fi trol Program for Microcomputers), -mi be- rezoritten in '-assembly P.O. Box 144 Camillus, NY 13031 which would form the basis for resi- tinguage to be effsctive. - dent PL/M programming. The need (315) 472-2582 Ha] for CP/M was obvious: 8080-based ktitem in rtDd for immediate deliw fxtay swkd urlmr wflull Ixhy rramnly. NYS residents add appropiate sales lax. computers with 16 K bytes of main Rm do not include shippin& VISA ad Master Chuge add 3%. C0.D. adus quire 25% deposit PI&S tubiat lo change without memory could be combined with micr

222 Jum 1981 0 BYIE. Publicatiom Inc Shugart's new (at that time) floppy- disk drives to serve as development systems. For the first time, it was feasible to dedicate a reasonably powerful computer to the support of a single engineer. But the use of PL/M on larger timesharing computers was considered sufficient, and the CP/M idea was rejected.

The CP/M Family CP/M was, however, completed by MAA in 1974. It included a single- user designed to eliminate data IQSS in all but the most unlikely situations, and used recoverable - ectory information to determine stor- age allocation rather than a tradi- tional linked-list organization. The simplicity and reliability of the file system was an important kgr-to the success of CP/M: file access to rela- tively slow floppy disks was im- mediate, and disks could be ch&ed without losing files or mixing data records. And because CP/M is a Spartan system, today's increased storage-media transfer rates simply t I I improve overall response. The rehe- .. ** -- '- - . . . ments found in CY/M are based on its I ATTENTION GOVERNMENT D P (1 simplikity, reliability, and a proper 1 match with Iimited-resource com- USERS AND PURCHASERS puters. By the mid-197fJsI CP/M added a We represent many fine micro products and manufacturers new philosophy to opexating system

on the GSA Schedule, including , design. CP/M had been implemented on several computer systems, each Apple, Cromemco having a different hardware'intedace. and Computer Carporation of America To accommodate these va& hard- ware environments, CP/M was de- Purchasing from the Schedule will save you the time ' composed into two parts: the .in- conwrned by the bid process. Products shipped throughout variant written the and world-wide. Visit or write any of our 1 in PL/M, and a small variant portion stores for more information or to receive our catalogue of , written in . This products represented. separation allowed computer sup- pliers and end users to adapt fheir own physical 110 drivm to the stan- dard CP/M product. Harddisk technology added yet another factor. CP/M customers re- quired support for disk drives ranging , the dependable stom from single 5-inch floppy disks to high-capacity Winchester disk drives. 257 West Street, Annapolis, MD ?l401 - (301)268-6505 In response, CP/M was totally ~de- 13A Allegheny Avenue, Towson, MD 21204 - (301)296-0520 signed in 1979 to become table- 9330 Georgia Avenue, Silver Spring, MD 20910,- (301)588-3748 driven. All diskdependent param- or Call (301)268-5801 eters were moved krom the invariant Cmeer Opportunities Available *An Equal Opportunity Employer disk opkrating system to tables in the

224 Junt I%I @ tIImPubrtiomlnc Circle 66 on Inquiry card. variant portion, to be filled in by the system implementer. CP/M is now a multifunction pro- gram whose exact operation is de- fined externally through tables and I/O subroutines. The widespread use of CP/M is directly attributed to this generality: CP/M becomes a special- purpose operating system when it is field-programmed to match an oper- ating environment. Through the ef- forts of system implementers who provide this field-programming, CP/M is used worldwide in close to 200,000 installations with over 3000 different hardware configurations.

CP/M, PLII, and PL/M have all played a role In the development of

EPOXY GLASS VECTOR BOA1 CP/M-86.

MP/M As single-user CP/M became wide- ly accepted, Digital Research began to develop a new operating system for real-time processing. The design called for a real-time nucleus to sup- port cooperating sequential pro- cesses, including a CP/M-compatible with terminal-handling capabilities. This operating system, called MP/M (Multiprogramming Monitor for Microcomputers), is a further refinement of the process model found in Intel's RMX and Na- tional's Starplex. As a side effect, the 5 SILICON POWER RECTIFIERS combination of MP/M's real-time nucleus with the terminal handler and the CP/M file system produces a traditional timesharing system with multiprogramming and multiterminal features. Timesharing allows programs to execute in increments of processor time in a "lock-step" fashion. In a timesharing context, a printer pro- gram, often called a spooler, might have the task of printing a series of disk files which result from program

POSTAGE ADD 10% FOR ORDERS UNDER 620.M) TERMg:mB CAMaRloGE. MASS, SEND CHECK SW0 825 FOR OUR CATALffi output. The spooler starts with a RATES ADD 5% FOR ORDERS BElWEEN $20.02 AND $50.00 ~~,,"~",~,"'~RD~R'$~~~~~":~$~~:~~~,":F,"A",'$:iIs ADD 3% FOR ORDERS ABOVE $50.00 MINIMUM MAIL ORDER (6.W. ST..CAMBRIDOE. MASS.^^^ disk-file name and, by using incre- ments of processor time allocated by the real-time nucleus, writes each line ' TEL. (6171 547-7053 SOLID STATE SALES from the file to the printer. Upon I f& P.O. BOX 748 OF OUR ORDERS WITHIN_ completion, the spooler obtains : 24 HOURS OF RECEIPT SOMERVILLE, MASS. 021 43 another disk-file name and repeats TOLL FREE 1-800-343-5230 :he process. You can, for example, the console). When the spooler is matches the file functions of CP/M so ;end the name of a disk file to the busy printing a file, additional file that MP/M provides a familiar pro- ;pooler and, while the file is being names may enter the input queue in a gramming environment. printed, edit another file in prepara- first-in first-out order. The implementation of queues is tion for compilation. The spooler and Process synchronization through transparent to an operator or system editor share processor time to com- queuing mechanisms is common- programmer, but it is important to plete their respective tasks. In gener- place, but MP/M treats queues in a MP/M's effective operation on limit- al, many such processes share pro- unique manner, simplifying their use ed-resource computers. Queues are cessor time and system resources. and decreasing queue management implemented through three different MP7M process communication is overhead. Queues are treated as files: data structures, depending upon the performed through queues (or they are named symbolically so that a message length. So-called "counting waiting lines) managed by the queue can be added dynamically. semaphores" count the occurrence of nucleus. The spooler, for example, Like files, queues have queue control an event with message length zero, reads file names from an input queue blocks that are created, opened, and are implemented as 16-bit tallies. posted by another process (which deleted, written, and read. In fact, the Single-byte messages are processed reads spooler command lines from set of queue operations closely using a circular buffer. Similarly, queues containing addresses are pro- cessed using circular buffers. In all r X Y X WRITE OR CALL FOR FREE CATALOGUE + Y Y ' other cases, Mf /M uses a general CALIFORNIA COMPUTER SYSTEMS HIGH IN QUALITY, LOW IN PRICE linked list, which requires additional 280 CPU, 4 Mhz, with one serial port; 12 slot S-100 mainframe, disk controller, 64K Dvnamic Ram. CP/M 2.9 ...... : ...... $1.645. space and processing time. It is this sorry, we cannot guarantee this price after June 20th. sensitivity to the capabilities of Interfaced to 2 Shugart 8", single sided, double density drives mounted in our own, beautiful MAX BOX with power supply and fan ...... $1,250. limited -resource computers that A complete S-100 system for under $3,000. THE BEST BUY ON THE MARKET. makes MP/M effective: while real- IMS 5000 and 8000 Systems time operating systems often incur 25 Outstanding long term reliability and performance. These systems feature a Z80A CPU, to 40% overhead, MP/M has been S-100 bus; double density drives (either single or double sided), DMA disk'controller, 64K RAM, 2 serial & 1 parallel port. Prices include the very finest implementation of streamlined to increase available CP/M@ available in the entire industry. Hard disk and multi user software options. compute time by 7% over single-user Desk top or desk enclosed. 5000 DT with dual, single sided mini drives...... CP/M. 8000 DT with dual single sided 8" drives ...... Like CP/M, MP/M is separated in- PER SCI-THE KING AND QUEEN OF DRIVES! Model 2998: Dual headed drives, total 3.2 MB unformatted ...... $2,300. to variant and invariant portions. . Model 277: Dual 8 inch drives, voice coil positioned, IBM compatible, 1600 K BYTES The file-system interface is identical per drive, unformatted ...... $1,210. to that of CP/M, with the addition of 299 300. Slimline cabinet and power for either 277 or ...... $ userdefined functions to handle non- DRIVES CP/M operations (such as control of The MAX BOX: Manufactured by john D. Ou>e,tsAssociutes. 8" dual drive cabinet complete with power supply... & fan. Will hold Qumes, Shugarts or Siemens. Excellent the real-time clock). Field-reconfig- desihn and emineerinn ...... 7 ...... $ 325. uration of MP/M allows a variety of ~iti2 shuga;t 800R drives $1,250. With 2 QUME Double sideddrives $1,650. I device protocols including CP/M- ..$265. 852.. .$365. 892...$500. Shugart...$ 450. 4 style busy-wait loops, polled devices, HAZELTINE 1500 ...... $925. IMS MEMORY 16 K static.. ... $350. and intempt-driven peripherals. In 1510 ...... $1,030. 32 K static ...... $6.50. fact, the variety of interface possibili- 1520 ...... $1,265. 64 K Dynamic with parity...... $755. 220 volt models, add $100 ties makes the MP/M implementer a 15' EXEC 80 with screen ..... $1,115. TEI MAINFRAMES, S-100 true system-software designer, since a We are proud to announce that we are fine-tuned MP/M system may oper- CENTRONICS 737 ...... $780. now a TEI stocking distributor. For the ate considerably faster than its initial best in mainframes. ...TEI!! Same as TRS-SO Model IV implementation. Apple serial/parallel interface ... $195. - TELEVIDEO CRTs What are. the refinements found in EPSON MXSOB ...... $550. 1 912..$780. 920.$850. 950..$1,050. MP/M? First, it is a state-of-the-art [j WE-EXPORT. Overseas Callers: TWX 710 588 2844 operating system based on current Phone 212 448-6298 or Cable: OWENSASSOC ! process-synchronization technology SEE OUR AD FOR NEW PRODUCTS ON PAGE 84 and microprocessor real-time system design philosophies. Process com- munication is conceptually simple JOHN D. OWENS and requires minimal overhead. Finally, it is the only operating sys- Associates, Inc. tem of its that can be field- 12 Schubert Street tailored to match almost any comput- Staten Island, New York 10305 er configuration. 212 448-6283 212 448-2913 212 448-6298 A

128 lum 1- 0 BME Publications Inc , . *'?- _IL CP/NET @PI/@, which can be stored in read- MP/NOS perf~- all disk fuktions CP/NET, introduced in late 1980, only memory, and that operates with through the network. leads a series of network-oriented op- a console, memory, and network in- The interface protocol is publicly erating systems that distribute operat- terface. MP/NET, on the other hand, defined so that non-MP/M or non- ing system functions throughout a is a complete MP/M system with an CP/M systems can participate in net- network of nonhomogeneous proces- embedded network interface that, work interactions. A server interface sors. CP/NET connects CP/M re- like CP/NET, allows local devices to for the VAX 11/780, for example, is questers to MP/M servers through be reassigned to the network. under preparation so that it can per the use of an arbitrary network pro- MP/NET configurations allow form I/O functions for a large num- tocol. Similar to CP/M and MP/M, MP/M systems as both requesters ber of MP/M and CP/M requesters. CP/NET consists of the invariant and servers with CP/M requesters. The principal advantage of portion, along with a set of field-re- Finally, MP/NOS contains the real- CP/NET is that all CP/M-compatible configurable subroutines that define time portion of MP/M without local software becomes immediately avail the interface to a particular network. disk facilities. Like CP/NOS, able for operation in the network en For purposes of CP/NET, this inter- face need only provide point-to-point data-packet transmission. Since the actual data transmission media are TELETYPE - PRICES SLASHED I GRAPHICS SOFTWARE unimportant to CP/NET, any one of Mode14320 AAA...... $so0 on line, real time, for the M9900 to the number of standard protocols can 220V. model with transformer installed drive the Microangelo. For use in design inside cabinet ...... $900 of PC board masks, IC masks and other be used, from low-speed RS-232C Model 43ASR. 8 level. 1' taoe. . .$2.595. applications...... $1,000. Limited suppiy of Model ;15 available. through high-speed Ethernet. Physi- 1 CORV"S HARD DRIVES 1 cal connections are also arbitrary, allowing active hub-star, ring, and Circuit card desi common-bus architectures. The invariant portions of CP/NET a Telex without operate under a standard CP/M sys- tem to direct various system calls over the network to an MP/M server. The MP/M server, in turn, responds to network requests by simulating the actions of CP/M. This simulation is transparent to an application pro- gram: any program operating under standard CP/M operates properly in the network environment. another micro, mini Suppose, for example, you wish to store common business letters in a central data base under MP/M and access these letters from a CP/M- Mode1740,8' single sided. based word processor. You begin by singledensity . $29.00 $26.50 assigning one local disk drive to the MP/M master, using the CP/NET in- terface. You then direct your word processing system to read the par- ticular letter on the assigned drive, causing the data to be obtained from the server rather than from the local disk. After local update using your ...... word processor, you can the result on your local printer or op- tionally assign your listing device to WE OFFER A the network for printing at the MP/M server. CP/NET is accompanied by three -JOHN D. OWENS related network operaling systems: Associates, Inc. CP/NOS, MP/NET, and MP/NOS. SEE OUR AD ON FACING PAGE CP/NOS is, in effect, a diskless

June l98l0 BYIT Publications lnc -- Clrcle 134 on Inquiry card.

THE NEW vironment, solving the problem that chine-code production. The compiler builders of network hardware face: is accompanied by a linkage editor the total absence of application soft- (compatible with the for- ware. Although the promise is there, mat), a program librarian, a set of networking is in its infancy, and runtime subroutines, and a relocating CP/NET is truly a software package macro assembler. At $149.95 you can't buy awaiting the evolution of suitable Thus, PL/I completes the final level a COBOL hardware. of the inverted pyramid of support better or one tools. The message should be clear to residing in less memory. the application programmer: it is not PL/I: The Application Language the system language or the operating Now with the new Nevada COBOL, you can In 1978, Digital Research in- use the programs developed by professional system which is important in the business over the past twenty vestigated the final level of software production of a final application. years to run the big IBM machines.And you can support: application languages. One Rather, it is the availability of a stan- develop and tailor programs on your micro and such language was to be supported run them on your micro or recompile and run dard, widely accepted application them on any . What's more throughout the operating system language that can provide program you can do it for about one-fifth the cost of product line, and the choice would longevity. Once expressed in PL/I Comparable COBOL compiler systems. have to be a multipurpose language. Almost all the popular microcomputers Subset G, the program can be trans- work with the CP/M operating system we use Further, the language would have to ported through the CP/M family of including Apple, TRS-80, North Star, Superbrain, be an international standard to pro- operating systems to a variety of Cromemco and so on. mote the generation of software by minicomputer systems. Digital Check the features; independent vendors. Standard you'll go Nevada COBOL. Research has a long-term commit- A powerful subset of ANSI-74, Nevada COBOL Pascal seemed a logical choice but ment to PL/I support for popular op- requires a scant 16K of RAM. It's available on 8" was rejected for several reasons. First, erating systems and processors. CP/M standard single density or 5-1/4" diskettes. Pascal is an ALGOL derivative with Price includes diskette and manual. Price for scientific orientation. Commercial manual only, 524.95. New Processor Architectures facilities in the standard language are We've spent little time discussing Four COBOL appllcatlons packages available too. absent: decimal arithmetic, file pro- processor refinements. What is hap- Four COBOL applications packages are cur- cessing, string operations, and error- pening to our software tools as we rently available. Each is priced at 524.95 for the exception handling were essential. augment our 8-bit machines with the diskette. The 73 page manual covering all four applications costs an additional 524.95. The Further, separate compilation and in- more powerful 16-bit processors? manual carries complete COBOL source code itialization of tables were not in the Will 16-bit processors replace 8-bit listings and superior documentation. language. There was a temptation to machines, or are they simply a tem- Package #I is the Budget Plan Report Generator. Here's an extraordinary time saver extend Pascal in order to include porary phenomenon in the transition and planning aid for both start-up and well these features, but these extensions to 32-bit machines? established businesses. would have defeated the benefits of There are several considerations Package #2 is the Personal Financial Planner to give you some eye opening insights into your standardization. when answering these questions. own personal spendlng habits. PL/I Subset G was the obvious First, 8-bit machines are economical Package #3 is Labels so you can print name choice. It satisfied scientific and com- to produce, their software systems and address labels. mercial needs and, because of subset are mature, and they satisfy the needs Package #4 is Pre-COBOL for use as a pre-processor of COBOL source programs. A great restrictions, was consistent and easy of a substantial computer base. programming aid. to use. The project was a bit daring, Therefore, we can safely assume that Order today or wrlte for complete details. however, because Subset G was un- 8-bit machines are here to stay. Phone (415) 751-1522 or address Ellis known in the computer community. Newer 16-bit machines are marginal- Computlng, 600 41st Ave, San Francisco, CA 94121. Nevada Cobol is also available at Lifeboat PL/I was viewed as a large IBM- ly faster, but they have substantially Associates, Discount Software, Westico, Business oriented language with huge, ineffi- more address space. To use this addi- Micro Products, Computer lnformarion Exchange cient that required tremen- tional address space, the computer and other qualrty computer stores. Mastercard, Visa, C.O.D.s,or checks accepted. California orders dous runtime support. must contain more memory, which please ~ncludesales tax. The Digital Research implementa- increases the computer system cost. tion of Subset G was started in As system costs increase, the mar- CP/M. TRS-80 and IBM sre TM's of D~q~ralResearch. Tandy Corp and I B M respeci~vely mid-1978 and completed two years gin between low-end minicomputers later. The compiler is a three-pass and high-end microcomputers system written in PL/M. The first diminishes, placing microcomputer two passes are machine independent hardware and software manufac- and produce symbol tables and inter- turers such as ourselves in direct com- mediate language suitable for any tar- petition with major minicomputer get machine. The third pass is largely manufacturers. The 16-bit machines, ELLIS COMPUTING machine dependent and is dedicated by their nature, introduce memory to code optimization and final ma- segmentation problems that are not SOFTWARE TECHNOLOGY

230 June 1981 O BYE Publications lnc present in 32-bit processors. A familiar program environment is availability of good application soft- Finally, we should note that 16-bit retained so that program conversion ware. At last count, there were about minicomputers are already out- is simplified. 500 commercially available CP/M- moded, and all serious manufacturers CP/NET and related network soft- compatible software products. are pushing 32-bit machines. This ware will be available sometime this Through the combined efforts of leads to the following conclusion: if year. Intel's 8087 (an arithmetic co- CP/M distributors, independent ven- we are tracking the minicomputer processor for the 8086) is of particular dors, and CP/M users, we are par- world, we can assume that the future interest since it directly supports ticipating in a software commodity will be with the 32-bit processors. binary and decimal operations, which market with quality and variety that Currently, however, 32-bit ma- substantially increase PL/M-86 ex- is unequaled by any minicomputer chines are not available in quantity. ecution speed. or mainframe manufacturer. The Even when they are available, there In addition to the 8086, the CP/M large CP/M customer base allows a will be delays while manufac,turers family will be adapted to the 16-bit vendor to produce and support a soft- tool up for production. At the machines that prove popular, with ware package at low end-user cost. moment, the 16-bit processors offer special interest in the 32-bit architec- This increases the customer base, an intermediate solution. Digital Re- tures as they become available. Dur- drawing more vendors with lower- search has provided initial support ing this development and rehosting, cost goodquality products. This for Intel's 16-bit machines-iAPX-186 however, the 8-bit processors will cyclic effect is, today, solving the and iAPX-286-which are versions of continue to be supported with new "software crunch." its 8086 product line. Intel pro- tools and facilities, since this con- The tools are available, and it is the vided PL/M-86, rehosted from the stitutes, without doubt, our best responsibility of independent soft- 8080 line, which was used by Digital customer base for some time to come. ware vendors to continue developing Research to generate CP/M-86 and their own specialized markets. In this MP/M-86. In both cases, the fun- Software Vendors way, computer software technology damental design remains basically the We've concened ourselves' with will reach virtually all application same as that of the 8-bit version, with three levels of software tools that sup- areas where low-cost, reliable com- the addition of memory management port the most important level: the ap- puting is required. Refinements? My and enhancements to the file system plication programs. A major reason friend, they're up to you.. that match new computing resources. for CP/M's popularity is the general Price-Perf ormance Breakthrough

OMIKRON has set new All purchasers of our Initial offerings include: Price-Performance standards MAPPER I CP/M* Adaptor in the micro-computer industry for the TRS-80 Model I are now Word P~OC~SSO~S with the formation of COUGAR eligible to receive Omikron's Languages - the official Omikron Users newsletter, the OMIGRAM--- Group. offering the very best in CP/M Data Base Managers Software at unprecedented group purchase rates. MAPPER'^ I11 for the Model I11 available soon. Write or call now for free brochure

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