File talk:HP 35 pocket calculator main board.jpg

Interpretation of picture content
This circuit board is probably tilt by 90°, as

1. the the two bores may bury 2 (of probably 4) screws holding together the casing.

2. the 25 unsoldered bores on the right side will probably orientate to the display contact wires..

Board is of glass and epoxy, two layers of printed lines. Lines are of copper (some points of green and blue-green corrosion products) and covered with gold.

Black sprinted "38 73" (top in picture) seems to descript production week and year of circuit board.

Nevertheless one component on the board indicate a somewhat later date 73/41. (from left und up)


 * 7311 golden IC "Mostek MK 6020..."
 * 7341 (black) round IC "Mostek MK 6022L..."
 * 7328 (red) round IC "Mostek MK 6023L..."
 * 7313 (black, after "2" in circle) electrolytic capacitor? (alu cylinder asymmetric leads couplings) 20DC+ (voltage? )
 * 7313 (black, after "2" in circle) electrolytic capacitor? (alu ...) 150D+ (voltage)

"1818-00xx" could be a project number, as it appears on ICs of two different producers or at least trade marks (Mostek and Ami)

--Helium4 (talk) 13:02, 12 July 2016 (UTC)