[4] It is a stripped-down version of Fujitsu's earlier FM-8 computer,[2] and during development it was referred to as the "FM-8 Jr.".

Although it was designed to be a cut-down version of the FM-8 (with the FM-7 costing 126,000 yen, compared to 218,000 yen for the FM-8[2][5]), most notably removing the (expensive) bubble memory technology, the FM-7 was given a more advanced AY-3-8910 sound chip capable of three voice sound synthesis, leading to a strong uptake among the hobbyist computer market in Japan and making it a more popular system than the FM-8.

Changes include a different character set that includes katakana and a few kanji, the ability to have graphics appear on the default text screen, and several new commands such as BEEP, CONNECT, MON, SYMBOL, INTERVAL, MERGE, RANDOMIZE, SWAP, and TERM.

While the BASIC EDIT command works the same as on Color BASIC, the cursor position is important on the FM-7: there is a small keypad on the upper-right of the FM-7 with cursor-control keys (arrows, INSERT & DELETE), and wherever the user decides to position the cursor, it will move it there and affect whatever is underneath it.

Secoinsa was a electronics supplier to Telefonica, the main Spanish telecom, and was eventually transformed into Fujitsu Spain.