LINC

The LINC (Laboratory INstrument Computer) was a special kind of computer known as a minicomputer. It was created in the early 1960s and helped start the development of personal computers we use today. Originally named the Linc, it was developed at MIT's Lincoln Laboratory and later renamed LINC.

Designed by Wesley A. Clark and Charles Molnar, the LINC was a small, transistorized computer with 2048 words of memory. It was very good at connecting with lab equipment, which made it useful for scientific research. The design was placed in the public domain, so anyone could use and build on it.

About fifty LINC computers were made, mostly by Digital Equipment Corporation. They cost around $43,600 at the time. The LINC included features like oscilloscope displays and special input devices, helping researchers manage and analyze their experiments in new ways.

Architecture

The LINC had 2048 memory spots, but only the first 1024 could run programs. The other half was used for storing data. It had special areas to help with tasks such as calling other programs and keeping track of positions.

The LINC could use a special area to help with calculations. It could connect to devices like a keyboard and a screen. It could also send and receive printed text using a special machine.

Control panel

The LINC control panel helps users follow programs step by step and spot mistakes. Users can pause the program at certain points or when it reaches a specific memory address. There are buttons to move one step at a time or to keep the program running. A knob and a switch let users change the speed, so they can see how fast the computer works, from very slow to full speed.

LINCtape

The LINC computer had a special part called LINCtape. This tape was very important because the computer's operating system needed it to work. It was like a small, quick disk but slower to find information.

LINCtape was small and fast, storing about 400,000 pieces of information. It could rewrite data in the same spots over and over.

Files on LINCtape had names with six letters, and each name could hold two types of files. Because the LINC had very little memory, it often needed to move data to and from the LINCtape. Later, a similar idea was used by Digital, called DECtape.

LINCtape was known for being very reliable, even if someone poked holes in it. The tape could still be read because it saved data in two places. It worked well even when the tape moved at different speeds.

Keyboard

The LINC computer had a special keyboard made by Soroban Engineering. Each key could lock into place when pressed, which kept other keys locked until the computer recognized the pressed key. This design could make typing slower and caused problems if someone tried to press two keys at the same time.

Later versions of the LINC computer used different keyboards, like the Teletype Model 33, Teletype Model 35, and Teletype Model 37, which were easier to use.

Knobs

The LINC had eight knobs that you could turn. The computer could read each knob with one command. The dial box was a good way for people to give information to the computer before mice were invented. For example, one knob could change how big a graph looks, and another could show a point’s exact value.

Text display

The LINC computer could quickly show text on a screen. Its screen was a small 5-inch square, like a device called an oscilloscope. This screen could also help fix the computer if needed.

The screen used a special material that kept images visible for a while. Programmers had to be careful because showing the same spot too often could damage the screen.

Teletype output

When the LINC computer needed to print information, it used a special machine called a Teletype Model 33. The computer changed its codes into another set called ASCII. It then used timing loops to turn a tiny part of its system on and off. This created the right signals to make the Teletype printer work at a speed of 110 characters per second.

Laboratory interface

The LINC computer had special parts that let scientists connect their own experiments to it. It included tools to change signals from sensors into numbers a computer can use, and it could also change numbers back into signals. There were six switches that could be used for control.

Variants

Besides the original LINC, a few other versions were made later. These included the micro-LINC from 1965, the micro-LINC 300 from 1968, and the LINC-8. Each of these versions had small changes in how they were used, the tools they used, and how fast they could work. Some also used newer technology called integrated circuits.

LINC-8 and PDP-12 computers

The LINC helped inspire some early computers made by Digital Equipment Corporation. They first created the very popular PDP-8 before making the LINC-8. The LINC-8 could run like either a PDP-8 or a LINC, but only one at a time. Later, they made the PDP-12, which could switch between acting like a PDP-8 or a LINC. The PDP-12 was the last of their machines to use LINC-style instructions.

MINC-11 computer

Digital made a version of the PDP-11/03 called the MINC-11. It was built into a portable cart and could be used with special laboratory tools for measuring and controlling things. It had a programming language called MINC BASIC that worked well with these tools. MINC stands for "Modular Instrument Computer." The name was chosen to remind people of the LINC, but this 16-bit machine was very different from the LINC and did not work the same way.