Monthly Archives: October 2022


PAL-1 6502 Computer

Introduction to the PAL-1 6502 Computer The PAL-1 6502 Computer is a clone of the KIM-1 Computer. In fact, most programs that will run on the KIM-1 will run on the PAL-1. I recently purchased this kit from Tindie. You can find the manuals here. This kit takes a day Read More »

PAL-1 6502 Computer

COSMAC 1802 LCD Timer

Introduction to the COSMAC 1802 LCD Timer In this section, we’ll build a COSMAC 1802 LCD Timer. I’m using the CDP1802 Microprocessor kit for this with an LCD display. The code will also display the value of the timer (up to 255) on the LED indicators. Basically, to run the Read More »

COSMAC 1802 LCD Timer

COSMAC 1802 Flasher

Introduction to COSMAC 1802 Flasher Logic In this section, we’ll write a simple program for a COSMAC 1802 Flasher. We’ll keep this as simple as possible, and use a couple delay loops. In this case, we’ll just use the Q output of the processor. The most important commands for this Read More »

COSMAC 1802 Flasher

A18 Assembler for COSMAC

Introduction to the A18 Assembler for COSMAC The A18 Assembler for COSMAC will convert your COSMAC assembly programs to object code. After that, you can send the file to your processor. I’m using Debian 11 for this example, but the A18 package also comes with a .exe file if you Read More »

Introduction to the A18 Assembler for COSMAC

ControlLogix Average Instruction (AVE)

Introduction to the ControlLogix Average Instruction (AVE) The ControlLogix Average Instruction (AVE) will find the average of a file. The file will simply be a group of numeric tags within an array. For example, we can use the AVE instruction to smooth out a noisy process variable to find the Read More »

ControlLogix Average Instruction (AVE)

ControlLogix Clock Calibration

Introduction to ControlLogix Clock Calibration Today, I wanted to discuss the ControlLogix Clock Calibration. Actually, that is a little bit misleading though, because we can’t really calibrate the clock itself. We can adjust it each day though. One way to do this is through the clock update tool. Another method Read More »

ControlLogix Clock Calibration

COSMAC 1802 Register Layout

Introduction to the COSMAC 1802 Register Layout The COSMAC 1802 Register Layout is a bit different from other processors. If you are used to the 6502, for example, you will find the addressing is much more indirect. For example, the P register is not the program counter. It simply points Read More »

COSMAC 1802 Memory Layout

Geoff Graham’s VT100 Terminal

Introduction to Geoff Graham’s VT100 Terminal Geoff Graham’s VT100 Terminal is a hardware emulator. This is a simple board that you can build yourself for a very reasonable price. I purchased a pre-built module on Ebay. There are several versions of this board. For instance, you can use a configuration Read More »

Geoff Graham's VT100 Terminal