I have repaired and restored my Single-Board-Computers(SBC) in 2008-2009 and are fully able to work again now. Dust-proof, behind plexiglas plates built up like in the following picture obvious.

The Architecture and the design of my Single-Board-Computer(SBC) is based on technology which is used to securely attach to points for electrical contact. This was a very effective way at that time to build Proto types. Also, changes could relatively be made simple. It was ideal to work with Logic-Analyser and Scope and the test points could always be reached ideally. At that time I used a electrical wire wrap tool and therefore could work more effectively and faster. This SBC at identical CPU chip and same cristal frequency was 47% faster than a PDP-11/73 (10 MHz) and 43% faster than a PDP-11/83 (15 MHz).

My highlight: Computer power was still a deficit in the time period at 1985. The DC-J11 CPU CHIP appeared at that time newly with the PDP-11/73 systems but was still too slow at some applications such as in the speech recognition. A new idea was born: Developing the fastest PDP-11 which ever there was. It was a lot of work in my spare time. In the end I was very successfully and the result was a Single-Board-Computer(SBC) based on the DC-J11 CPU chip. I could test a 18 MHz running DC-J11 CPU chip which is running in PDP-11/93 only briefly however my SBC running with the 15 MHz DC-J11 CPU chip still was approx. 5% faster than the PDP-11/93. Therefore. I can say that my SBC is the fastest PDP-11 worldwide, or with other words, a SBC based on standard DEC CPU-components , which is abe to execute PDP-11 instructions at the fastest possible speed worldwide. I am still very proud of it. The disillusionment: I had introduced my design at engineering in the USA. Result: The feedback only was ignorance. I was very disappointed and frustrated at this point in time and said goodbye to the thoughts of continuing this project. The final dissolving of DEC then stood and I left this company after some years. I set up my own company ( SHD GmbH ). The daughter product was developed, see the next point.

Detailed descriptions & informations:

Technical information , PDF Document ( only in German at the moment ).

Video via YOUTUBE

At this point in time, my personal goal was to design a 4 axes CNC control system , consisting of a microprocessor based hardware, extensive software to get features implemented like 3D simulation and automatic milling-cutter radius correction. My choice was the MC68000 CPU from MOTOROLA. This CPU has a simular instruction set like the PDP-11. I had enough experience in real time programing and implemented a simplified real time and multitasking kernel based on context switching. A very reasonably priced development system was an ATARI-ST at that time. The ATARI BIOS was also emulated in my kernel and brought me the great advantage to write most of the application in a high level language, like GFA-Basic or Mark-Wiliams C. Unfortunately, the complete software had to be ported to the PC platform because MOTOROLA disappeared with the last product, MC68040 from market. Too bad...what disillusionment ... coming from MC68000 with the fantastic assembler instruction and have to change over to the Intel 386/486 instruction based on load/store architecture. I still can not quite understand why Intel architecture so strongly gained acceptance. Better marketing ist my opinion.

Detailed descriptions & informations:

Technical information, PDF Document ( only in German at the moment ).

Circuit-diagram , PDF Document.

SW-Tools : MicroMonitor Source code, Down-Load Program and much more.

Video via YOUTUBE