The 80386 microprocessor is taking hold of the 32-bit micro market

Computer Weekly

November 27, 1986

Computer systems manufacturers are starting to unveil machines configured around the Intel 80386 microprocessor.

The 80386 is not the only true 32-bit micro available to system builders. Motorola and National Semiconductor, for instance, also offer true 32-bit devices. Like the 80386 these processors can run multiuser operating systems, control powerful engineering workstations and artificial intelligence applications.

But a report from International Data Corporation (IDC) underlines the enormous significance of the Intel processor. It says that the strong appeal of Intel's processor over other leading 32-bit CPUs is its ability to run existing PC software. The 80386's success is virtually guaranteed by maintaining upward compatibility with Intel's previous processors.

IDC points to the $6 billion worldwide installed base of software like 1-2-3 from Lotus Development Corp and dBase from Ashton-Tate. These are written for personal computers configured around Intel's 16-bit microprocessors and running under Microsoft's DOS - the operating system called PC-DOS on IBM Personal Computers and MS-DOS on IBM compatible machines.

This mass of 16-bit software can run in most cases without modification on computers configured around the 32-bit 80386 and under the existing 16-bit versions of DOS. Moreover, in future they should be able to run on the same computer alongside new 32-bit applications written for future 32-bit versions of DOS.

In addition, DOS should be able to run simultaneously on a computer with other operating systems - proprietary systems as well as those used on many different computer models like Unix, Pick, Concurrent DOS and BOS.

Bob Lefkowits, director of software research at market analyst Infocorp in California, expects personal computers configured around the 80386 to dominate the professional PC market in two or three years.

Compaq Computer Corporation is the first PC vendor to launch an 80386-based computer as a vehicle primarily for DOS applications. This is the Deskpro 386. But Lefkowits doubts if many companies will follow Compaq's lead until IBM enters the market with an 80386-based machine.

That might not happen until the end of 1987, he thinks. One important reason is the need for software to exploit more fully the capabilities of the 80386.

Microsoft is working on a new version of DOS for the 386, supporting multi-tasking and greatly extended main memory addressing.

But IDC believes that IBM may decide to make life extremely difficult for manufacturers of IBM compatible PCs. It could use the virtual memory capability of the 80386, with its support for multiple operating environments, to implement a proprietary virtual monitor on its 80836-based PC. This would not be available to other PC manufacturers in the way DOS is.

IDC believes it might be a virtual manager designed from the ground up for the 80386-based PC, or it could be based on IBM's existing mainframe virtual machine operating system, VM/370. Either approach would include DOS among the operating environments supported and thereby provide compatibility with the huge base of DOS applications.

At the same time it would present PC compatible manufacturers with the extremely difficult and costly task of having to engineer a virtual operating system that worked like IBM's proprietary product.

IDC believes IBM would leave part of the hardware and software architecture of an 80386-based machine open to vendors that add value to IBM-PCs, notably peripheral manufacturers and independent software vendors. This is because IBM recognises the role these play in maintaining the success of the PC line. So independent software vendors could continue developing applications as they have done for the existing IBM-PC family.

A virtual machine operating system modeled on VM/370 and called VM-386 is already under development for the 80386 at Softguard Systems in Santa Clara, California. VM-386 will enable multiple operating systems like DOS and Unix to run simultaneously on the same 80386-based machine.

To develop VM-386, Softguard is using a Series 386 system from Corvus Systems, the first vendor to unveil an 80386-based computer.

The 80386 is not the first Intel device to provide virtual memory support. The 80286 does as well. But Intel stresses that the 80386 is the first of its devices to use virtual memory for running multiple operating environments simultaneously.

Another systems software vendor taking advantage of this capability is Digital Research. The company's European software director, Howard Korstein, reveals that Digital Research is developing an 80386 operating system based on its existing multi-tasking, multiuser environment, Concurrent DOS. It will be able to run with DOS on the same machine.

At present Digital Research offers its users a degree of DOS compatibility within Concurrent DOS through support for some DOS system calls and common ROM BIOS functions. But compatibility is restricted to DOS versions no more recent than Version 2.1.

"The 80386 finally gives silicon support for Digital Research's systems software plans," declares Korstein.

The existing Concurrent DOS is one of three multiuser operating systems that can run on the first all-British 80386-based computer, the Super (Micro Turbo 386 from Rair a subsidiary of Technology for Business). The other two are Unix System V and BOS from BOS Software.

At present the user can only run one at any one time, although Rair is expected to enhance the Turbo 386 with a virtual machine environment supporting simultaneous execution of all three sometime in 1987.

Regardless of its multiple operating environment, the 80386 seems to be valued for its capability to run individual multiuser operating systems more quickly and efficiently than earlier Intel processors.

During the first half of 1987 Microsoft's Unix-based multiuser operating system, Xenix, will be available on the Compaq Deskpro 386, in addition to DOS. Compaq's UK software manager, John Softly, notes that the Deskpro 386 will be able to support 16 users under Xenix, four times the number supported under Xenix on Compaq's 80286-based Deskpro 286.

Alistair Jacks, chairman of BOS Software, views the 80386 as an ideal vehicle for his company's BOS operating system. He says: "At last with the 80386 we have a microprocessor that will not be sold as a single-user machine."

Frank Petyak, director of worldwide sales at Pick Systems in Irvine, California, points to his company's implementation of Pick on the 80386. It supports 17 users and should be able to run DOS as a task early in 1987.

The first two vehicles for the 80386 implementation are the Compaq Deskpro 386, users of which can buy the software from Pick Systems itself, and the Access 386 from Advanced Logic Research, also of Irvine. Petyak notes that Pick is already used widely on PC Configured around the 8088, 8086 and 80286 processors from Intel, including the PC/XT and PC/AT from IBM.

But what of DOS itself on 80386-based machines? Microsoft chairman Bill Gates confirmed that his company is working on future versions of DOS to take full advantage of the 80386.

A Microsoft spokesman adds that existing DOS versions, including the latest, DOS 4.0, do not even take full advantage of the 80286 processor, let alone the 80386.

DOS 5.0, expected by the end of the first quarter of 1987, will exploit the power of the 80286 with multi-tasking under Microsoft Windows, and will make better use of the 80386 than existing DOS versions. But a launch date for DOS 6.0, otherwise known as Advanced DOS, the version tailored specifically for the 80386, is much further away, maybe as much as two years.

It is not expected to be a multiuser system, but it will exploit the 32-bit addressing of the 80386. Existing versions of DOS can directly address no more than 640 Kbytes of main memory - a tiny amount compared with the massive four Gbytes that can directly addressed by the 80386.

Vendors of DOS applications software look forward eagerly to this great leap forward in direct main memory addressing. Peter Price, sales director of Slough-based expert systems vendor Expertech, hopes DOS 5.0 will provide up to eight Mbytes of direct main memory addressing, so the knowledge bases used by Expertech's Xi Plus expert system shell can be totally memory resident.

With 640 Kbytes, no more than about 300 rules from a knowledge base can be held in main memory at one time. The rest have to be paged from disc.

Price thinks that ample main memory will enable expert systems to realise their potential as intelligent user interfaces co-resident in main memory with application packages. Of the many different potential types of co-resident application, Price identifies spreadsheets as the most promising.

This view is shared by Tom Cahill, UK sales director of Ashton-Tate, who envisages a spreadsheet program like his company's dBase III interacting with a user, courtesy of an expert system interface.

Cahill also sees great potential for co-residence of spreadsheets with computer-aided design packages on powerful PCs. A spreadsheet program can be used to store and manipulate the reference points of a drawing.

Cahill notes that dBase III is already used on existing PCs with the Autocad package from Autodesk, but he thinks that such co-residence will come into its own on 80386-based PCs.

Another facility expected to fully realise its potential on 80386 PCs is the exchange of spreadsheet information between mainframes and PCs, according to a spokesman for Lotus Development.

A package called The Application Connection (TAC) providing such a link will be launched by Lotus in the UK in the first quarter of 1987.

The importance of compatibility with DOS and DOS applications is underlined by Motorola's collaboration with Hunter Systems, a software house in Palo Alto, California. Hunter is implementing DOS on Motorola 68000 processors in C. This is the intermediate language in which Unix is written and which enables applications to be ported between Unix on different types of processor.

Microsoft's DOS is written in Intel assembly language, so it cannot run on other types of processor.

Intel's upwards compatible family of microprocessors

  			8086	  8088	    80286

Bus interface (bits)    16   	  8  	    16
Internal data path      16  	  16  	    16 (bits)
Bus band width  	5 Mbytes  2 Mbytes  12.5 Mbytes
(maximum)              	per sec   per sec   per sec
Memory  		1 Mbyte   1 Mbyte   16 Mbytes
addressability
Virtual memory   	No  	  No  	    Yes. 1 Gbyte per task
On-chip memory  	No  	  No  	    Yes
management and protection

                        80386

Bus interface (bits)    32 
Internal data path      32 (bits)
Bus band width	        32 Mbytes
(maximum)     	        per sec
Memory  		4 Gbytes
addressability
Virtual memory	        Yes. 64 terabytes per task
On-chip memory	        Yes. With
management and demand
protection paging