Introduction Sumraar This Document Describes Design Features of The

LMI LAMBDA MACHINE OVERVIEW

Introduction Sumraar

This document describes design features of the LMI Lambda machine which is currently being developed as a joint effort between LMI and Western Digital Corporation. The data presented herein does not constitute a specification for the machine. Detailed spec- ifications will be released when tests have been successfully performed on prototype hardware.

The system will consist of a LISP processor designed by LMI for the personal computer being developed by Western Digital based on the MIT Nu Machine. The resultant system will be substantially lower in cost than the present Series 111 LISP Machine but will have increased functionality and speed. Particular emphasis is being placed on maintaining software compatibility with existing LISP Machine software. Accordingly, the Lambda processor will be offered in two configurations, one which requires no software change and another with extended address capability which will require only simple changes to system microcode and possibly some changes in user software.

The new system is described in three sections consisting of a description of the Western Digital machine, the LMI Lambda processor and system configurations involving the interaction of two or more machines.

Western Digital Nu Machine

A major philosophy in the design of the Nu Machine is the concept of modularity. The system is designed so that it can exist in a large number of configurations due to the flexibility of the Nu Bus, a 32 bit hierarchical Bus design. A typical block diagram is illustrated in Figure 1. Standard system building blocks include the processor, main memory, disk and disk control t network interface, system diagnostic unit and video controller and display. The modules are discussed briefly below:

Processor - The standard processor to be supplied with the Nu Machine is the 10 MHZ version of the Motorola 68000 chip. The processor will be configured with a cache and will execute the UNIX operating system. This should provide processor speeds of about 1 MIP. Nu Machine UNIX will support a multi-user environment, virtual memory via demand paging, and is based on Berkeley-UNIX now available on VAX* systems. Because Berkeley-UNIX was chosen, migration of existing programs under VAX UNIX should be exceedingly easy with 90% of programs requiring only recompilation.

The initial software will include: C PASCAL Fortran 77 Window system Several screen editors, including EMACS SIGGRAPH core library of graphics programs (Level 1) INTERNET TCP software providing mail, remote file transfer, and remote login under ETHERNET II The programs will be able to address a full 24 bits of virtual memory.

It should be noted that this processor is not intended as a LISP processor. The LMI Lambda processor is a different set of boards which can be used instead of , or in addition to, a Western Digital processor.

Keyboard - There are 100 physical keys on the keyboard. The keyboard has unlimited rollover, meaning that a key- stroke is sensed when the key is depressed no matter what

*TM Digital Equipment Corporation

2 i can at the time. The hardware other keys are depressed are being pressed at any tell exactly what physical keys when any key is depressed and given moment; it knows means that the machine could when it is released, which the keyboard in any manner be programmed to interpret whatsoever.

be moved is a point device that can The Mouse - The mouse motions are sensed by Z^T^. a flat surface. These responds by moving a cursor the machine, which usually corresponding manner. around on the screen in a

the mouse which are used to There are three buttons on Typically the user specify operations to be performed. the mouse and specifies an points at something with buttons. Rapid double operation by clicking the mouse distinguished from single clicks are conventionally specific context there are uP to clicks. Thus, in any be performed with the mouse six operations that can Middle, Middle Double, invoked by Left, Left Double, Right and Right Double clicks.

interfaces will be available Network Interface - Network to either -^T-A^-^—7whicn will permit connection 11. Development of this the CHAOSNET or to ETHERNET naturally be dependent on when latter interface will be agreed on. the network protocols can

be available m -dules memory. - Physical memory will configured into 32 bit words ZT^Z Megabyte per board, simply by the addition Physical memory can be expanded of memory boards. board will be a SMD Disk Control - The disk control to connect to a controller which will be able disk drives. This variety of commercially available controller will reside on the Multi-bus.

3 System Diagnostic Unit - The system diagnostic unit is a microprocessor-based diagnostic computer which will aid in the maintenance of the system. This processor will also be able to perform system diagnostic functions on the LMI Lambda processor, although it will also be possible to debug the LISP processor by connecting it directly to the debug port of another machine in the same manner as with the present LISP Machine.

The system diagnostic unit also contains a Multi-bus interface as well as several R5232 serial ports so that industry standard peripherals can be used with the machine.

Video Controller and Display - The standard video monitor for the Nu Machine will be a high resolution black and white CRT (1024 x 1024 pixels) . The screen will be non- interlaced and will refresh at 60Hz for flicker-free operation. Optional displays include both standard and high resolution color.

Pricing - As with the Lambda Machine, detailed pricing on the Nu Machine will not be available until system testing has been completed; however, the purpose of evaluation prices of the Nu Machine will range from $15,000 to $30,000 depending on the options selected (the $30,000 option would include a processor, video controller display, keyboard and mouse, network interface, system diagnostic unit, main memory and small disk) . Delivery of these machines is expected in the summer, 1982.

LMI Lambda Processor

The design of the Lambda processor attempts to significantly upgrade the performance of the present LISP Machine while maintaining a high degree of software compatibility with the existing Series 111 LISP Machine. This compatibility is maintained by offering the machine in two configurations:

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Configurations with Two or More Machines

Two or more Lambda Machines can be connected together over the network along with other Nu Machines not containing LISP processors. In this manner, a number of environment configurations can be envisioned which would gain maximum usefulness from the LISP Machines. For example, one or more LISP Machines can be used in conjunction with several minimally configured Nu Machines. A version of the EMACS editor, a subset of the ZMACS/ZWEI editor of the LISP Machine is available which can run on the 68K processor. Hence, text editing and simple program editing can be done on these low cost machines and the files transferred over the network to a LISP Machine for program execution. An advantage of this type of system configuration is that the low cost machines can be easily up- graded to fully functional Lambda Machines by plugging in the appropriate boards to the Nu Bus.

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1. 32-Bit Configuration - This configuration is identical to that of the present LISP Machine, having a 32-bit word length which contains a 24-bit pointer, five bits of data type and three bits of special storage information. This processor, while operating at considerable higher speed (around 2X) , will run the identical software as the Series 111 Machine. Physically it will reside on four boards which will plug into the Nu Bus.

2. 40-Bit Configuration - An optional configuration for the processor will be a 40-bit machine which will extend the pointer size and, hence, the addressable virtual memory to 32-bits. The remaining eight bits are unchanged for the existing machine. In this manner, there will be maximum possible software compatibility with the existing design while substantially increasing the amount of addressable memory in the machine. This configuration furthermore expands the maximum integer and floating point number size to 32-bits which has allowed the implementation of the lEEE floating point standard. The hardware is designed so that this functionality increase will not sacrifice machine speed and the 40-bit version will, therefore, run at the same rate as the 32-bit version As the tag bits have a fixed field regardless of the data type, substantial microcode changes will not be needed. Furthermore, the 40-bit configuration maintains a byte orientation and, therefore, no changes to devices such as peripheral controllers will be necessary.

Lambda Machine Pricin It is anticipated that a complete Lambda system (including the necessary Nu Machine components) will sell for around $60,000 in single quantities in a configuration which will include one megabyte of main memory and a 300 megabyte disk.

-5- " FIGURE 1 Typicaj system Block Diagram