Ken Clark's Professional Page

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Employment History:
Barr Systems, LLC | Barr Systems, Inc. | Microdyne | Tropical Communications
Data System Designs | Rockwell International | Alachua County Data Processing

Notable Solutions, Inc. (NSi)

2013 - present

Principal Software Engineer

E-mail: ken.clark at

Barr Systems, LLC


Product Architect
Barr Systems
4500 NW 27th Ave
Gainesville, Florida 32606-7031

E-mail: ken.clark at

Duties and Responsibilities

My primary duties involve architecture and development of new product solutions at Barr Systems, LLC.

Barr Systems, Inc.


Product Development Manager
Barr Systems
4500 NW 27th Ave
Gainesville, Florida 32606-7031

Major Accomplishments

My first task while at Barr Systems was to write an X.25 stack to go with our new (at the time) SNA RJE product. I had acquired intimate knowledge of X.25 (and SNA) while working at Tropical Communications.

After completing this task my role grew to include continued development and support for our existing SNA Gateway product and our SDLC and 802.2 DLC protocols. I was also assigned to play a back up support role for our very popular and rapidly growing Print/370 product. In this capacity I became intimately familiar with the mainframe channel (Bus & Tag and later ESCON).

When Barr began work on a new channel card I was assigned the task of developing the on board channel logic engine. Eventually this role extended to architecting the core software used by our NT, OS/2, Novell, UNIX and DOS device driver solutions.

I also played a major role in the design and implementation of BARR/RJE, an add on option to our existing Barr Enterprise Print Server product. (Special thanks to John for providing wonderful code to clone - albeit Assembler!)

Microdyne Corporation


Senior Systems Analyst


During my brief stay at Microdyne I managed the maintenance and support activities for our X.25 based VT100 and 3270 terminal emulator product as well as for our X.25 and QLLC/SNA APIs.

I ported our X.25 API code to a V40 based coprocessor environment and implemented additional level one support for the X.25 product.

I performed Bell Atlantic and DDN certifications of our X.25 product.

Tropical Communications, Inc.


Vice President and Senior Systems Analyst

Tropical Communications was a small three man company whose charter was to produce and market a PC based multi-session X.25 terminal emulation product.


We completed this task in less than a year. I was chiefly responsible for the development of the X.25 physical, link, session and PAD layers and played a major role in the overall product architecture.

This product was eventually sold to Microdyne Corporation. This arrangement included my going to work for them in a product support and enhancement role.

Data System Designs, Inc.



Data System Designs was a small consulting company which specialized in providing customized computer based business solutions. The company included two software developers as well as two local Certified Public Accountants.


Our major accomplishment was the development of a full featured back office accounting system written for a large municipal bond underwriting firm. The final incarnation of this product was written in C and ran in a multi-user UNIX environment. The product included an extensive customer, security and inventory database. Daily reports included security position, inventory, settlement and more.

Rockwell International


Software Engineer

While at Rockwell I worked in the math modeling group supporting STS ground operations at Kennedy Space Center. This group was responsible for modeling the behavior of shuttle systems as well as most ground support equipment.


My first project was to model a cooling unit used to cool orbiter systems while on the ground. I was also involved with some of the orbiter main engine simulations.

I was chosen to head up a two man team charged with trying to break the GLS (Ground Launch Sequencer) software. This critical piece of software runs the countdown down to the T-20 second point, at which time on board computers take over. The GLS software had a bad reputation of crashing and causing other problems during tests. My team went over the GLS code with a fine tooth comb. We made a number of recommendations to the team responsible for it.

I recall well that the GLS software was not the reason the first shuttle launch attempt was aborted. I also remember the head of launch operations stating, after that first aborted launch attempt, that he had expected the GLS software to be the problem, but that it was not.

Alachua County Data Processing


Senior Systems Programmer

The Alachua County Data Processing Center was responsible for the various data processing needs of Alachua County, Florida. We had an IBM System 370/135 running DOS/VS. While I was there this was upgraded to a model 140 (main memory went from 1/2 megabytes all the way to 2 megabytes!!). This system supported a large 3270 terminal network. Most of the major county offices were connected over dedicated leased lines. Most of our batch programs were written in COBOL and most of the CICS programs were written in 370 Assembler.


My first task was that of assisting one other developer on a rather large and ambitious minicomputer based information switching system. After a couple of months the developer I was working with resigned and I continued on the project for another nine months or so. We were using a TI-960A minicomputer which was connected to the data center's mainframe and to a number of 3270 workstations. Our software emulated the 3270 workstations to communicate with the host and emulated the host to communicate with the workstations. This was all done using BSC (bisync) protocol. We were also connected to a non-IBM asynchronous host in Tallahassee. The goal of the project was to allow terminal operators of the Criminal Justice Information System to access multiple host databases "simultaneously".

After the minicomputer project I moved on to a number of other tasks. These included general system troubleshooting, CICS maintenance and the development of a new signon security program. My final assignment was to lead a team of three or four developers in the implementation of the newly purchased MSA accounting and payroll systems. Payroll was fully implemented and the general ledger nearly so before I left to work for Rockwell International.

Last updated: 01/19/2013 (by Ken Clark)