IBM 5110 Service Logic Manual Posters and IBM 5110 Display Symbols (standard and international)
The IBM 5110 was a portable personal computer system available in 1978. It was an upgraded version of the IBM 5100 released in 1975.
The SLM (Service Logic Manual) is a set of large posters. Each poster is about 4x2 sheets of paper (8.5x11") size. Digitizing these required a large scanner and was done at 600 DPI resolution. The SLM is not a component level schematic, but is the logical (pin, signal, 0/1) relationship between part on the system cards. This includes also pin numbers, to guide what aspects of the system are involved for the various sub-systems.
The repository also contains the Display symbol set available on the IBM 5110. The Display is configured to pick a particular Default (via jumpers on the board), but this can be programmatically adjusted (using the FLS file from BASIC, similar option in APL), or pressing HOLD, then doing SHLFT 0-9. The IBM 5110 BASIC Reference Manual contains the set of symbols.