STB1157 - Lawrence Livermore Labs - MST-80 - Part 8 - Finally Fixed

In this video we look at the core issues with the system logic and diagnose and repair it.

The Lawrence Livermore Labs MST-80 was a digital electronics and microprocessor trainer designed in the mid-1970s around the Intel i8080 8-bit microprocessor. It was targeted at universities and colleges. If operate both in octal and hex notation. Octal (base 8) predated the common use of hexadecimal (base 16). Early datebooks for the i8080 were laid out using octal notation.

The MST-80 featured 512 bytes of RAM and 768 bytes of EPROM. As small as this sounds by today’s standards a lot of core computing tasks could be accomplished. 256 bytes of the ROM were designated to hold user programs.

The MST-80 featured semiconductor RAM and EPROM which at the time it was designed were still new technologies.

The user interacted with the system via a keypad for input and control. For output is used LED displays that could display a single byte in octal or hexadecimal. It also has a set of LEDs that can be used to monitor signals such as the address bus, data bus and control signals.

It provided easy access to the address bus, data bus and control signals vi socket connections. A small prototype board could then be used for user circuits.

The system featured a single-step mode. This allowed the user to single step through a program one instruction at a time.