It has been mentioned before but I will try to give a better example. The boards have hints and are silkscreened to try to remove the possibility for human error. When I was learning about biological sciences (a LONG time ago) the one lesson that stuck with me was human error. At the time the number one cause for incorrect blood test results (such as blood type testing) was incorrect vial labeling. This same problem was also evident in my time working in software (software bugs are human errors and human errors either fail to detect them or fail to fix them properly).
Here is a higher resolution of a previous posted image of a board. It's small and simple but contains enough to perhaps show what sort of things have been done. I have a document for general board assembly (discusses things such as the components, the labeling and alternative components). I also have documents for groups of boards that contain the BOM. I will try to go back and provide better information for the more obscure components (such as compatible part numbers) but I don't have much available time at the moment. I just spent two straight days building (another) System 11 board and still I see another two to three await building.
Points to note about the board:
- Components that are polarized have a square pad to indicate pin #1. For diodes or LEDs this is the anode (positive or long leg). For ICs this is the pin that corresponds to the notch or dot and the silkscreen indicates the notch.
- All components are labeled with what the actual value of the component is. Resistors are square and capacitors are oval. The value is encoded in the body using the digit/digit/multiplier/[tolerance] scheme. Two significant digits and a multiplication (power of ten). The tolerance is optional. For resistors it defaults (unlabeled) to 5% (J) and for capacitors it defaults to 20% (M). Resistor wattage is also included if the wattage is not the default (of 0.25W).
- Key pins are marked in the silkscreen (although for this board it is not marked due to space limitations).
It is still easy to incorrectly install the components so a minimal level of board experience and some attention to detail before committing (soldering) the component is required. The value labeling is invaluable to me. I don't need to lookup the BOM. I just need to make sure the value matches the silkscreen. A few of the older boards I made have silkscreen errors but most of those boards have either been built (by me), provided with an errata tag or are not available directly.
Here are two more full resolution images to give better examples of the above.
I have tried VERY hard to make it as easy as possible for a novice person with some level of experience with electronic components.