Heathkit

he H8 was the first computer available from Heathkit, released in late 1977. Computer systems from other manufacturers were also available as kits, but the practice was quickly falling out of favor. Most were available only as fully-assembled systems.

Although the H8 was relatively inexpensive at $379, the stock H8 included only the chassis and the CPU card.
At least one H8-1 memory board with 4K of RAM ($140) must be installed to run any appreciable software programs.
To use an audio cassette drive for data storage, the H8-5 Serial I/O card ($110) must be installed.
To upgrade to the floppy drive system, at least 16K of RAM must be installed.

For reliability, the CPU board came pre-assembled, but everything else was available in kit form. In 1978 the H-17 dual-floppy drive ($675) became available - previously only an audio cassette recorder could be used for data storage.