The Majority Gate

After a long while I resumed work on the Arithmetic/Logic Unit. I wired up a test circuit for the 3-resistor majority gate, which i use in the ALU for the joined AND and OR functions. I was lucky and the gate worked as expected. Dieter Müller has written an article about the majority gate and it's use for ALU design. Website now offline (2010) and email address invalid. I don't know what has happened to him :-/

Working on the compiler

Working on the compiler for user-space (as opposed to microcode) programs. It seems it's gonnabe a compiler, not an assembler, with c-like syntax and some c++ goodies. Finally i got stuck. Using a non-typed script language to write a compiler has it's disadvantages too.

Working on microcode

Working on the microcode and microcode assembler.The microcode is organized in 2 planes of 16k * 24-bit codes. There is a 1-instruction pipeline which imposes a 1-instruction latency on code branching: In every microcode instruction a flag is selected. This flag is tested at the end of the previous instruction and determines from which code plane the next instruction is read. The assembler takes care for the most of this brain hazzard.

The Control Unit

2009-01

Production of the first board by PCB-Pool (voucher). It is the control unit, which is abbreviated as "SSW" for German "Schrittschaltwerk".

2009-02

I'm in the Homebuilt CPU Webring.
The Control Unit is finished:

K1-16/16 Control Unit

EagleCAD certainly has it's quirks.

EagleCAD certainly has it's quirks.

2008

Planning. Design and evaluation of circuits. First i drew the PCBs in Freehand, a graphics program. But Freehand was bought by Adobe and Adobe terminated development. So i bought a non-profit license for the circuit design and layout program from CadSoft, which is quite affordable.