Tag: otf

A rendering of a 7-pin dot matrix font, as used by the Epson MX-70 reduced-cost printer from the mid-1980s.

(github mirror: scruss/nic7pin: a 7-pin dot matrix font, as used by the Epson MX-70)

Name

Seiko Epson Corporation is named as “son of EP-101”, for the world’s first compact, lightweight digital printer. I’m Scottish, and in Scots Gaelic “son of” is mac. Unfortunately, that prefix has been co-opted by an overpriced computer vendor. In Gaelic, nic means “daughter of”, so as an oblique compliment to Epson, this font is named daughter of 7 pin. It seemed like a good idea at the time …

Coverage

ASCII.

Design Size

The 12 point design size is meant to reproduce 12 characters per inch horizontally, and six lines per inch vertically.

Source

While this font is produced entirely by one Python FontForge script, the code is too ugly for you to look at. The included mx70.json is likely more useful: it contains all of the pin definitions keyed by character name.

Licence

© 2026 – Stewart Russell, scruss.com with Reserved Font Name nic7pin

This Font Software is licensed under the SIL Open Font Licence, Version 1.1. https://openfontlicense.org/

[I do not agree with SIL’s missionary work in any way, and the use of this licence isn’t an endorsement of SIL.]

References

• Epson MX-70 User’s Manual, Appendix C: Character Set (p.83)
• identify this peripheral – Identifying a dot-matrix printer from its font – no descenders, no half-pixel shift, mid/late 1980’s – Retrocomputing Stack Exchange — where I found out about this silly thing.

Based on E73 from a couple of days ago, this is extended for full ASCII coverage:

Design Size

The 12 point design size is meant to reproduce 10 characters per inch horizontally, and six lines per inch vertically.

Variants

The ECMA 42 standard states (§ 4.2):

The dots … are circles of 0.4 mm diameter nominal or polygons of equivalent area.

So I went slightly overboard on the dot shapes:

   A73      Circles
   A73D     Diamonds
   A73L     Lozenges
   A73P     Pentagons
   A73S     Squares
   A73T     Triangles
   A73St    Stars
   A73H     Hearts(!)

Source

While this font is produced entirely by one Python FontForge script, the code is too ugly to include here. The included a73.json is likely more useful: it contains all of the pin definitions keyed by character name.

Licence

© 2026 – Stewart Russell, scruss.com with Reserved Font Names A73, A73D, A73L, A73P, A73S, A73T, A73St and A73H.

This Font Software is licensed under the SIL Open Font Licence, Version 1.1.
https://openfontlicense.org/

[I do not agree with SIL’s missionary work in any way, and the use of this licence is in no way an endorsement of SIL.]

Reference

• ECMA-42: Alpha-numeric character set for 7×9 matrix printers; 1st edition, December 1973 (withdrawn): “This Standard defines the printed image and the nominal dimensions of a font for 7×9 matrix printers. The characters have been designed for both human and machine readability.”
• E73