Tektronix 4010 wiring color to numbers chart ??

Yes, and so do you :-). Actually, the same code is used by HP and Tektronix (and probalby others), and it's the obvious one that htey expected anyone working on the hardware to know. It's the resistor colour code : 0 : Black 1 : Brown 2 : Read 3 : Orange 4 : Yellow 5 : Green 6 : Blue 7 : Violet 8 : Grey 9 : White. So a wire numbered '903' on the schematic is white wih a black stripe and an orange stripe. In theory the black stripe should be wider, but I don;t think they ever required you to check this (in other words yoy won't find 903 amd 930 wires in the same instrumetn, or at least not in the same area of the instrument). Tektronicx often colour-coded their header sockets in the same way. Socket 4 would be a yellow plastic moulding, for example. -tony