Postal Mechanisation Tools
These are intended to be simple tools for interpreting a pattern of code dots or bars. At present there are two versions:
- An inward code translator for the "standard" patterns of c.1973-94 with fourteen dot positions. This works out the notation for the dot pattern in standard xx/yy format and states which inward code it corresponds to.
- A translator for the "transitional" codes of the 1990s with a pattern of bars, which were used during the switch to OCR/VCS and before 4-state codes came in.
The general idea is that you match the dot or bar pattern on your cover by clicking on the appropriate dots/bars to turn them on or off, and the interpretation appears in the box below. "Start" (S) and "format" (F) positions were there to provide fixed points for the machinery to work with and dots/bars are always present in those positions. "Parity" (P) positions were for error checking, and a dot/bar was printed only if needed to make the number of dots/bars in the appropriate part of the pattern even. The parity bars in this tool will be switched on and off automatically. These positions can be a big help when deciding exactly how many spaces there are between dots/bars ...
It is intended to add outward code translation and interpretations of other formats at a future date if agreement to use the necessary data can be secured.