Portable Source-level Debugger

Telesoft was one of the first commercial developers of the language Ada, for a large number of platforms. Telesoft wanted a source level debugger for use on programs without recompilation, easily portable between host and target system pairs. We designed a highly retargetable host/target debugger architecture and lead the development effort, managing teams in the US and Sweden, handling all aspects of specification, production, project management, and customer presentations. The project broke new ground in the techniques for and development of source-level debuggers.  It has proven portable in less than 2 months to system including Sun SPARC and other Unixs, Cray 2 and X-MP, MIPS and Motorola based systems, and others.

Java Precursors

In the mid-1970s, Ken Bowles started the UCSD Pascal Project at the University of California, San Diego.  UCSD Pascal was a highly portable implementation of Niklaus Wirth's Pascal programming language.  Java's portability model and byte-code interpreter psuedo-machine approach are based on UCSD Pascal.  By 1980, UCSD Pascal ran on essentially every available type of computer and had 10,000 users.

As an early member of the project, we had primary responsibility for the second and later versions of the lead interpreter implementation, for the DEC PDP/LSI-11.  We also developed the native compiler code generator control-flow validation suite, the Texas Instruments TI990 native-code generator, and dozens of device drivers (often at the rate of one or two a day).

As a principal in Volition Systems, we performed analysis and feasibility study of a Modula-2 compiler implementation for LSI-11/UCSD Pascal and Z80/CP-M. We also consulted on design of a microcoded hardware implementation of a psuedo-machine for Modula-2 and UCSD Pascal  a precursor of Sun's new MAJC chip.

Ada Development & Validation

Primary technical responsibility for compiler port and development of automated testing system for the first Ada compiler validations on Sun and AT&T Unix, two of the first handful of Ada validations.  Co-manager of round-the-clock six person testing team.

Compiler port, native code generator, and runtime for IBM 370 Ada under VM/CMS and MVS/TSO.  Co-author.

Robot Control Network

For White Data Systems, we developed the algorithms and driver software for a collision detection, variable back-off network for industrial robot control and communication. This new generation of more sophisticated network was used in some of the largest and most advanced commercial materials-handling and inventory control installations at that time.

Early 68000 Debugger

We specified, designed, and developed the machine-level debugger/monitor/boot ROM for one of the first commercial 68000 boards, for QBus and Multibus.  The monitor included a memory diagnostic system configurable for LSI-layout sensitive diagnostic of different memory chips.  The recursive implementation of the debugger was used to debug itself.

Unix Guru

From maintenance of the Logo interpreter on 4.1 BSD on sdcsvax - one of the early Internet backbone sites (later ucsd.edu)  through recent projects for clients like SDRC and Seagate, we have always served clients as informal or formal Unix system and network administration advisor.  We can still be reached at dar@ucsd.edu - our earliest net address, in operation since 1980.