PC1601LRS-GSO-B is covered by this 140 KB PDF datasheet, a character display module coded in the Powertip style for a 16 by 1 format. The GSO-B suffix distinguishes it from sibling versions, so the option letters on the real part should be checked against the sheet. Expect mechanical drawings, pin functions, absolute maximum ratings and interface timing. It is handy when sourcing a replacement, wiring the module to a controller or checking whether a dead display is getting the correct logic and backlight supply.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @acodis_lcd_datasheets_EDID. Enginerys does not host this file.
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The standard format for schematics, block diagrams, power-sequence charts and service manuals.