RBBS in a Box Volume 1 #3.1

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Date: 4-Nov-83 08:12 PST From: Jeffrey Stone To: net.micro Subject: IBM's Professional PC's The XT/370 Professional Workstation The XT/370 is a PC/XT to which a 370 processor on three boards has been added. These boards provide an emulated 370 processor, 512k of RAM, an emulation of IBM's 3277 model 2 display, and a connection to an IBM S/370 mainframe. To complement these hardware enhancements, IBM also announced VM/PC (Virtual Machine/Personal Computer), which in conjunction with PC-DOS 2.0, functions as the control program for the XT/370 when it is running in 370 mode. Under VM/PC, the XT/370 supports one of three sessions selected by a "hot key": - a local CMS session (i.e., a CMS session running on the XT/370), - a remote 3277 model 2 emulation session (a session displayed on the XT/370's display but run on a remote S/370), or - a remote 3101 emulation session via an optional asynchronous connection. When running in PC/XT mode, the XT/370 is compatible with current PC/XT capabilities including use of "foreign" expansion boards. The Hardware The XT/370 consists of a standard PC/XT chassis with eight expansion slots. Three of these slots are populated with special S/370 emulation cards. PC/370-P card The P card implements an emulation of the 370 instruction set. The card contains three microprocessors. 1. One of the processors is a heavily modified Motorola 68000 produced by Motorola under license to IBM. This chip implements the general purpose registers, the PSW, instruction fetch and decode logic, and 72 commonly used S/370 instructions. Since the chip is manufactured under license to IBM, it is doubtful that it will appear as a Motorola product. 2. A second processor is a slightly modified Motorola 68000 which will be listed in Motorola's catalog. This chip emulates the remaining non-floating point instructions, manipulates the page table, handles exception conditions, and performs hardware housekeeping. 3. The third microprocessor is a modified Intel 8087 which executes S/370 floating point instructions. This chip is interfaced as a peripheral rather than via the normal 8087 co-processor linkage. PC370-M card The M card contains 512KB of parity checked RAM. This memory may be accessed from the P card or from the XT's native 8088 processor. Concurrent requests are arbitrated in favor of the 8088. While the M card does live in an XT expansion slot, it is also connected to the P card via a special edge connector. 16-bit wide transfers between M card memory and the P card are effected through this connector (normal XT memory transfers operate in 8-bit wide chunks). When operating in native PC mode, the M card's memory is addressed as contiguous memory beginning at the end of the 256KB memory of the system's motherboard. In native PC mode, the XT/370 has 640KB of usable RAM - some of the M card's memory is not used. When operating in 370 mode, only the 512KB RAM of the M card is usable (i.e., the 256KB on the system's motherboard is not available for the VM/CMS system). The first 480KB of this memory implements 480KB of real S/370 space. The remaining 32KB on the M card functions as a microcode control storage area for the second P card microprocessor. Of the 480KB of S/370 memory, the first 64KB are consumed by VM/PC leaving 416KB of real memory for user programs. User programs larger than this are handled via paging. PC/3277-EM card This card attaches the XT/370 to a S/370 mainframe via a local or remote 3274 control unit (connection via coaxial cable). When VM/PC is running, the EM card enables the XT/370 to emulate a 3277 model 2 using the IBM monochrome or color display (since the 3277 does not support color, if a color display is used, then default colors are utilized). Under VM/PC, the EM card is also used in uploading and downloading of data between a host VM system and the XT/370. A 3274 coaxial connection can transfer data about as fast as today's small winchester disks (over 600,000 bytes/second). Software The XT/370 can run in native PC/XT mode or in S/370 mode under VM/PC. Under VM/PC, the user can alternate via a "hot key" between a local CMS session and a remote 3277 session (or optionally, a 3101 emulation session). VM/PC on the XT/370 will support all VM/CMS software conforming to the following requirements. - Uses no more than one virtual address space. - Runs in a virtual machine of up to 4 MB. - Supports 3277 model 2. - Does not rely on protection exceptions. - Does not depend on S/370 DOS emulation. - Does not exceed fixed disk capacity. - Does not require more than 416KB of real memory. - Does not rely on internal VM/SP and/or HPQ structure and formats. - Does not rely on time dependent operations. In effect, this means that most S/370 CMS software will run on the XT/370. Some notable exceptions: - PROFS does not run because it utilizes multiple virtual machines, - ISPF does not run because it depends on CP internals, - any program using VSAM will not operate properly because VSAM uses non-standard disk formats (S/370 DOS emulation); this means that PL/I software using indexed files will not run on the XT/370. VM/PC does not offer a true VM-like environment. Rather, it provides an environment in which CMS applications can run. Non-CMS VM applications will not run on the XT/370. Within the supported CMS environment, each CMS minidisk (simulated disk-pack on which a CMS user stores many files) is implemented as a PC-DOS file. This is very nice since it enables the use of PC-DOS commands to backup CMS data and to move this data between XT/370 workstations. IBM will license IBM S/370 software for use on the XT/370. Licensing agreements are made in conjunction with the original mainframe S/370 license (i.e., for now, you must be a S/370 licensee to license IBM S/370 software for the XT/370) and the corresponding software must be downloaded from a S/370. License fees run a few dollars per month per XT/370 workstation for each licensed software unit. IBM has announced the following software to be available for licensing. Product Monthly Charge ---------------------- ---------------- OS/VS COBOL Compiler and Library $19 OS/VS COBOL Library 6 COBOL Interactive Debug 21 VS FORTRAN Compiler and Library 17 VS FORTRAN Library 4 IBM BASIC Processor and Library 21 PL/I Optimizing Compiler and Library 21 PL/I Transient Library 4 PL/I Resident Library 4 Pascal/VS 11 Assembler H 9 Document Composition Facility (SCRIPT/VS) 18 License fees for IBM CMS software are charged to the mainframe licensee rather than to the XT/370 proprietor. But how can IBM enforce these fees? When this question was posed at a recent professional meeting, IBM representatives responded that IBM would continue to trust its customers. In corporate environments, where the XT/370 will be sold, this is probably quite reasonable. The VM/PC system must also be licensed. It is provided on six floppy diskettes and includes the VM/PC Control Program, CMS, XEDIT, EXEC2, local and remote file transfer utilities, and the 370 Processor Control package. 370 Processor Control is a general purpose debug facility similar to the debug facilities found on the operator consoles of S/370 processors. It runs on the XT/370 under VM/PC as one of several concurrent sessions (including a local and a remote CMS session). It can be entered from any other session and can exit to any session. 370 Processor Control enables the user to: - stop and start the processor, - stop the processor by real instruction compare, - generate an external interrupt to the processor, - edit (full screen mode) the following: * 370 general purpose registers, * 370 floating point registers, * 370 control registers, * 370 PSW, * 370 storage, both real and virtual, * 370 page address table. The user interface to the 370 Processor Control session relies heavily on function keys whose usage is displayed on the screen. XT/370 VM/PC CMS and CP commands are similar to S/370 VM/SP release 2 commands. From the looks of the list given in the VM/PC announcement notice, most CMS and CP commands are supported. VM/PC XEDIT and EXEC2 are compatible with the corresponding software of VM/SP release 2. Included on the distribution diskettes with VM/PC is a remote server program which may be used on a S/370 host to support communications between the host and the XT/370. This program affords the following functions: - Spool, disk, and file services, - VM/PC service request processing, - Logical and physical communications management. We aren't quite sure how you would upload this program to a host without the services of the program itself. Performance The XT/370 has been in the field at a number of locations for several months. First rumors on performance of the XT/370 CPU indicate that it is approximately half of a 4331 when running a commercial instruction mix. When running scientific codes, twice the performance of the 4331 is expected. In general, the CPU is categorized as a .1 MIP processor. This may not sound terribly impressive in times when we are used to multi-MIP single chip micros. Remember however, that .1 million S/370 instructions are likely to produce substantially more computing than .1 million instructions of your standard micro chip. The XT/370 running in S/370 mode can access the 512KB on the M-card. Of this 512KB, 32KB are reserved for microcode control storage; 64KB is used up by the VM/PC Control Program. This leaves 416KB for user programs. Should a user program require more memory than this, then VM/PC will use a paging area on the XT/370's hard disk swap pieces of the program in and out of memory according to usage. Swapping on the little 10MB hard disks is going to be considerably slower than on the large disks used with mainframes. Thus, programs larger than 416KB will probably run very slowly. Field test users report long delays in loading large programs into memory even when these programs are well under the maximum for non-paged operation (e.g. XEDIT). Again, this is directly attributable to the relatively slow operation of the XT/370 hard disks. While 10MB sounds like a great deal of disk space to those of us who have been using floppies, in the mainframe world 10MB is just a drop in the bucket. In its XT/370 product announcement, IBM cites the following example of disk utilization. bytes(MB) System storage (VM/PC, DOS) 1.6 OS/VS COBOL Compiler and Libraries 1.0 Document Composition Facility 0.6 Page file (1 MB virtual) 1.0 User A disk for CMS data/programs 3.0 Spooling for printing 0.5 User area for PC data/programs 2.3 ------- total 10.0 Here we have but 1MB as a paging area (reduces the maximum VM/CP virtual job size from 4MB to 1MB) and .5MB for spooling. The 20MB XT/370 option (see below) will undoubtedly be quite popular. Configurations and Prices XT/370 (IBM machine number 5160) is announced in two configurations: model 588 and model 568. The 5160 Model 588 is the XT-like system we have been describing. It includes one floppy and one 10MB hard disk drive (or as IBM calls it, a "fixed" disk drive). The price for this configuration is $8995. VM/PC is available for an additional one time license fee of $1000. Model 568 is the same as the 588 but without the hard disk and the hard disk controller board. To augment this configuration, you may purchase a new IBM PC option, the 5161 expansion unit model 3. This unit comes with two 10MB hard disk units, a hard disk controller, and eight system expansion slots (six full-feature and two short slots). The XT/370 model 568 is priced at $6720 and the expansion unit price is $4970. Thus a 20MB XT/370 costs $11690. Add $1000 for VM/PC and you're all set to go for about $13K (tax included). The three XT/370 boards are available as an upgrade for the IBM PC/XT. The upgrade kit contains the boards, installation instructions, and a logo kit to change the name plate to read "IBM XT/370". Thank heaven for IBM! The price of the XT upgrade is $3790. Significance of the XT/370 The XT/370 announcement appears to be a battle tactic of the "offense is the best defense" sort. IBM is telling us that it has decided how to support professionals and that a 370 workstation running IBM's proprietary software will be the way. Add in a PC to run popular software. The battle is a multi-fronted affair with the central antagonists being none other than that now famous duo - AT&T and IBM. The bit players are drawn from the ranks of small UNIX-based hardware vendors, Microsoft, and the other UNIX software vendors. The XT/370 suggests an alternative future, the first realistic alternative future, to a world where every professional desktop carries a UNIX workstation. Through this first announcement, we begin to visualize applications running in a VM environment which include smooth, responsive, graphic interfaces. The XT/370 has all the hardware. It just needs a little software work. For the present, however, the XT/370 probably isn't all that useful. Yes, of course there are some professionals who will immediately benefit from being able to run RAMIS or FOCUS or some other database or decision support tool. But most of these people are well supported by their trusty old 3270's and the XT/370 doesn't buy them that much. In any case, they will continue to need a high bandwidth umbilical to a mainframe. The promise of the XT/370 isn't really available today (or in second quarter of '84 when the machine will materialize for real). What's lacking is - as usual - SOFTWARE. But IBM has at least provided the base. Now its up to developers, both inside and outside of IBM, to take over. The 3270-PC The 3270-PC combines the functions of IBM's 3270 display system with those of the IBM PC and can support up to seven concurrent activities: one local PC-DOS 2.0 session, four remote mainframe sessions, and two local electronic notepads. Users can associate activities with windows and can designate which windows appear on the system's display, the size of those windows, and their positions. With the assistance of the 3270-PC Control Program, information can be copied between windows with the exception that a PC-DOS window may not receive information. An important limitation of the 3270-PC is that it does not support PC-DOS applications which make use of "APA" graphics (APA stands for "all points addressable", IBM's jargon for bit-mapped). This eliminates all PC software which operates in non-text mode. Only programs which can run on a PC equipped with IBM's monochrome display adaptor (non-APA display) will be able to run on the 3270-PC. The Hardware In appearance, the 3270-PC closely resembles the original PC. Unlike the XT/370, however, the 3270-PC is not essentially an upgrade of the the PC - nor is an upgrade kit for the PC available. The differences stem largely from the display section of the hardware which has been substantially altered. Hardware window management functions have been added and are implemented on a new board, the 5151/5272 display adapter. This adapter is used in place of the PC's monochrome or color/graphics display adapter and provides text-only displays in eight colors. While the extended character graphics of the PC are available, no bit-mapped graphic capabilities are supported. The 3270-PC can be configured with the PC's monochrome display for black and green text-only operation or can be fitted with a new product, the 5272 color display. The new display is a 14-inch color monitor from Matsushita. Initial reports indicate that the display produces superb text images. Color text images displayed by the 5272 are said to be of the same general quality as those displayed by the PC's monochrome display. The 3270-PC includes a new keyboard which addresses some of the complaints about the PC's keyboard. Even though the keyboard contains more keys, the layout is apparently improved. The return and shift keys have been enlarged. The cursor keys have been pulled out of the numeric keypad to form their own little group between the main set of alphanumeric keys and the numeric keypad. Twenty function keys arranged in two rows of ten have been added at the top of the keyboard. To help clarify keystroke operations, the new keyboard is annotated. Blue legends are used to designate PC specific functions; black legends indicate 3270 functions. The 3270-PC includes two expansion boards not found in the PC. 3270 System adapter Supports communication between the 3270-PC and the remote 3274 controller through which mainframe hosts are accessed; connects to a 3274 via coaxial cable; one physical 3274 connection can support four logical connections; can optionally be attached to 43xx display/printer adapter. Keyboard adapter Interfaces the new keyboard to the system unit; the key keyboard connects directly to this board rather than to the mother board as it does for the PC. The system unit provides eight "expansion" slots of which six will normally be filled upon delivery with the 3270 system adapter, a memory expansion board, the display adapter, the diskette drive adapter, the printer adapter, and the keyboard adapter. If a hard disk is added, then the seventh slot will be used for the hard disk adapter. Certainly, the memory expansion and printer adapter functions could be coalesced onto a single foreign board, but this would only slightly relieve slot paucity. Software The 3270-PC runs under control of the 3270-PC Control Program in conjunction with PC-DOS 2.0 and supports concurrent operation of up to four remote host interactive sessions, up to two local notepad sessions, and one PC-DOS session. The Control Program enables users to associate sessions with display screen windows and to manage those windows via a set of functions that IBM calls advanced screen management. Window DefinitionUsers can define windows that permit viewing of all (up to 2,000 characters) or part of a presentation space. In IBM's parlance, a presentation space is a logical display area presented by a single host. PC-DOS presentation spaces are 2,000 characters (i.e., 25 lines by 80 characters), remote host spaces are up to 3,440 characters, and notepad presentation spaces are 1,920 characters. Window View within a Presentation Space Up to seven windows may appear on the screen at once. Each window is associated with a distinct presentation space. Windows may be as large as the screen or as small as one character and may be positioned at any point within their presentation space. Thus, a window which is 20 characters wide by 4 lines long might show the first 20 characters of the last 4 lines of an emulated 3270 remote host session display. Window size and position within the presentation space may be changed at any time without effecting the content of the presentation space. Window Positioning on the Screen Each window may be positioned to appear at any position on the 3270-PC's physical display screen. A window may partially or completely cover one or more other windows. Windows may be repositioned at any time without effecting the content of the associated presentation spaces. The Active Window At any given moment, one window on the 3270-PC screen is the active window. When users enter information from the keyboard, it is directed to the session associated with the currently active window. Users can switch between active windows through keystroke commands. Background/Foreground Color Users may define the foreground and background colors of host session windows not using extended data stream attributes. Users may also define the background color for the 5272 screen (i.e., the color to be displayed in areas not occupied by windows). In addition to the advanced screen management functions, the control program offers a number of related facilities which help users to further manipulate and utilize the 3270-PC environment. Copy Data Between Windows Data may be copied within or between any presentation space except into the PC-DOS space. MS-DOS screen management is simply not prepared to handle block data inserts as is the 3270 world. Notepads The notepad activities may be thought of as local electronic scratch pads which users may use at their convenience. The contents of a notepad may be saved and restored at any time using PC-DOS files as the storage medium. User Defined Keystroke Sequences Keystroke sequences may be captured and recorded (in PC-DOS files) for future playback. Screen Configuration Memory/Recall Users can define up to ten screen configurations each of which describes a set of windows configured in any way, and can cause any one configuration to be displayed upon command. PC-DOS files are used to store the configuration information. Screen/PC-DOS Session Window Print A full copy of the display screen may be printed on a local printer. Similarly, a full copy of a PC-DOS presentation space may be printed on a local printer. Host Session Window Print A full copy of any host presentation space may be printed on a local printer or on a 3274 attached printer (or a 43xx display/printer attached terminal printer). System Status Line The Control Program maintains a status line at the bottom of the screen which displays current configuration information including the name of the active window. Help + Tutorial The Control Program includes a Help function which displays active workstation functions and sessions and an online tutorial that explains and simulates system functions. The tutorial is a standard PC-DOS program which can be run on any IBM PC. Host File Transfers The Control Program with the assistance of a host-based IBM 3270-PC File Transfer Program can initiate transfers of ASCII, binary, and EBCDIC files to and from remote hosts. The host-based file transfer program is host licensed and is available for VM/SP 2.1 and MVS/TSO. Configurations and Prices The 3270-PC (IBM machine number 5271) is announced in three configurations. The 5271 model 2 is a single dual-sided floppy system which includes a system unit with 256KB RAM (expandable to 640KB) and keyboard. The price for this configuration is $4,290. To this will normally be added a PC monochrome display at $345 or more likely, the new 5272 color display at $995. The 3270-PC Control Program will be available for a one time license fee of $300. All told, getting into a 3270-PC, even one with only a single floppy, will cost at least $4935. If you want the nice color display the price is $5585. This model does not include a printer adapter as standard equipment. The 5271 model 4 adds a 64/256KB memory expansion board with 64KB RAM installed, a printer adapter and printer cable, and a second dual-sided floppy disk drive to the features of the model 2. The base price for the model 4 hardware is $5319. Adding the Control Program and a monitor, the dual diskette system is priced at $5964 for a monochrome version and $6614 for the color version. The 5171 model 6 is like the model 4 except that a 10MB hard disk is added instead of the second floppy. The base price of the model 6 is $7180. Adding a monitor and the Control Program brings the total to $7825 for a monochrome system and $8475 for the color version. The following table summarizes 3270-PC pricing information. single dual diskette + diskette diskettes hard disk (model 2) (model 4) (model 6) ------------------------------------ | | monochrome | $4935 $5964 $7825 | display | | | | color | $5585 $6614 $8475 | display | | ------------------------------------ 3270-PC PRICES INCLUDING DISPLAY AND VM/CP S/370 installations supporting attachment of 3270-PC systems will want to license IBM's host-based 3270-PC File Transfer Program. The charge is a one time license fee of $600 for each VM/SP or MVS/TSO operating system environment within which the file transfer functions will be used. Significance of the 3270-PC If you are one of those corporate knowledge workers who deals on a daily basis with many information sources most of which are available through an SNA network and you don't need sophisticated graphics - then the 3270-PC will be a Godsend. For the rest of us, maybe the 3270-PC raises more questions than it answers. We wonder how really useful multiple concurrent host sessions will be. Do professional users really want to manipulate multiple independent sessions to accomplish their jobs? We feel that it would probably be better if application programs gave them more comprehensive support. Of course, if several host applications were designed from the ground up to live in a multiple window environment, then great benefits could be expected. But the 3270-PC, unlike Lisa, can't easily be integrated with applications to promote sophisticated cooperation. Even so, for corporate information managers, the ability to concurrently access several SNA-based databases will be greatly appreciated. The 3270-PC does provide the essential tools for viewing, extracting, combining, and manipulating such information: multiple concurrent terminal sessions, cut and paste capability between the sessions, PC productivity tools, and up/downloading of host files from PC-DOS files. But, the tools are limited to non-graphic uses (unless you count "character graphic" applications as graphic), and the PC window cannot receive information from other windows. It is also interesting to note that CMS and TSO do not allow a user to run multiple simultaneous sessions under a single user identification. Nonetheless, for uses involving multiple SNA-based applications, the 3270-PC will be the surest bet for a while. Jeffrey Stone Menlo Park, CA October 21, 1983