2 open source boards using the 74HC21
Real designs built with the 74HC21, from public GitHub projects: a quick way to see how others power, decouple and connect it. Each board comes with its KiCad files, full parts list and a render — and you can simulate its firmware on HardLabs.
Sus
stonedDiscord
175.3 × 80.6 mm83 parts2LBSD-2-Clause4
6502 RAM Card
acwright
100 × 57.6 mm15 parts2LCERN-OHL-P-2.047
The 74HC21 in open source designs
The gallery holds 2 open source boards using the 74HC21 from 2 GitHub repositories; a typical one measures about 137.6 × 69.1 mm and carries around 49 components.
100% are two-layer designs, the rest use four layers or more, and 100% carry an open source license.
The most starred is 6502 RAM Card by acwright.
What boards using the 74HC21 are built for
74HC21: common questions
Where can I find a 74HC21 reference design?
Each of the 2 boards on this page is a real design using the 74HC21. Open one to see how it is wired up, with the full BOM, a render of the layout and links to its KiCad files.
How big is a typical board using the 74HC21?
The median is 137.6 × 69.1 mm, and 100% are two-layer designs.
What is the most popular open source board using the 74HC21?
By GitHub stars, 6502 RAM Card by acwright, with 47 stars.
Can I simulate one of these boards using the 74HC21 before building it?
Yes. HardLabs turns a board's netlist and BOM into a working simulation, so you can boot and test firmware against it with no hardware on your desk.