There was no standard case and thus designs varied.

Manufacturer

Promoted by Radio Electronics magazine (US)

Model

Mark-8

Date Launched

Announced in the July 1974 issue of Radio Electronics

Price

$5 for construction plans.
$47.50 for the circuit boards.
About $250 for the components.
The Mark-8 was never sold ready-assembled or as a complete kit.

Microprocessor type

Intel 8008 @ 0.5 MHz

ROM size

No ROM (ROM chips were expensive)

Standard RAM

256 bytes

Maximum RAM

16 kilobytes

Keyboard type

16 toggle switches.
It was possible to add a full keyboard.

Supplied language

None
The Mark-8 was programmed directly in machine code.

Text resolution

Display was just four rows of 8 LEDs.

Graphics resolution

No graphics

Colours available

Red LED

Sound

None

Cassette load speed

No facility for external program storage

Special features

One of the very first personal computers to use a microprocessor.

Good points

Relatively low price.
Had an I/O port for interfacing.

Bad points

Lack of permanent program storage meant the user had to enter programs manually as bit patterns on the toggle switches every time the computer was reset.
Fiddly to build.

How successful?

Around 7500 sets of plans and 400 circuit boards were sold.
It is not certain how many Mark-8s were successfully built.

Comments

The Mark-8 was designed by Jon Titus and published in Radio Electronics magazine as a construction project.
It was intended primarily as an educational machine to learn about digital computers, rather than to perform any practical task.