For sale is a reproduction Ohio Scientific 495 prototype board with correct NOS Molex KK-156 connectors installed. I produced these boards from 4000 DPI scans of an original OSI 495 board which was depopulated, cleaned, and sent to a company that specializes in the conversion of circuit boards into CAD drawings. As such, these boards are a 1:1 clone of the original, including the artifacts of a hand-drawn layout (pads/traces slightly askew, not all holes perfectly centered, et c.). This was intentional to preserve the look and feel of the original. These boards are fabricated as true single-sided, with no plated through holes, no solder mask or silkscreen, and HASL lead surface treatment (trace tinning).

The included Molex KK-156 connectors are New Old Stock parts and are the old-style translucent natural Nylon, not modern opaque white plastic. They have been soldered down with Kester 63/37 "44 Core" lead solder.

This is a prototype run, and you can see a tiny flaw in one of the power traces (fourth from the bottom in the first picture) -- a hairline in the trace due to a misalignment in the Gerber files. This doesn't affect operation at all (you could cover it with solder if you like) but has been corrected in the CAD files.

This board differs from the original in that the FR4 material is slightly thicker (standard 0.062" vs. original 0.055"), which greatly improves board stiffness but still fits the Molex KK-156 connectors (they were designed for 0.062" boards). I've also included a date/project indicator on the bottom left corner in the copper layer (third picture) so these don't end up getting resold as originals.

The fourth and fifth pictures are for illustrative purposes only: they show the original OSI 495 board from which this one was produced next to a reproduction, and a reproduction board with components and Molex connectors fitted. Neither the original OSI 495 board or the components shown (aside from the Molex connectors) are included in this auction!

This listing is for the last three spares from the initial run. The Buy it Now price reflects my cost-per-board. I'm trying to determine what sort of interest there is for these boards, so feel free to make an offer!