For sale are new-made reproductions of the Ohio Scientific 502 6502 CPU board. These boards were produced from 4000 DPI scans of an original Ohio Scientific 502 board and are 1:1 with respect to trace and hole placement. They were run on standard thickness FR4 stock, which is thicker than original OSI stock, to reduce the excessive flex experienced with original Ohio Scientific products.

These boards have been scanned and reproduced as part of the Ohio Scientific Preservation Project. Full documentation is available in PDF format online. You can learn more about the OSI Preservation Project at http://osiweb.org or http://www.glitchwrks.com/osi -- please join the OSIweb forums! See our other listings for more reproduction and newly designed Ohio Scientific boards!

The OSI 502 supports the following features:

• 6502 CPU
• 8K static RAM using 2114 SRAMs
• 4K ROM
• 6850 ACIA, usable as console or cassette interface
• OSI 48-pin bus compatible

Full schematics provided courtesy of Dave Fenyes/osiweb.org at the documentation link provided.

The OSI 502 is essentially a minimal single-board computer: with a serial terminal and power supply, it can run a ROM monitor or OSI BASIC with no other boards. Plugging it into an OSI backplane makes for the start of a complete Ohio Scientific expanded system. We do not currently offer a parts kit for this board.