Abstract: To allow a salesman to record data relating to merchandise items which are to be ordered, a logging device comprises a casing in which are housed a keyboard, a display and associated circuits. The salesman locates a sheet containing a list of merchandise items, on the casing between two columns of light-emitting diodes. At the start of entry of an order, the top left-hand LED is illuminated under the control of a central processor unit, which simultaneously addresses a main memory storage location corresponding to the item alongside that LED. Data, such as quantity required, can then be keyed into that storage location, which already contains an identification code for that item. The salesman then operates a key which causes the CPU to scan through the LEDs, and the storage locations, in turn, until the next required item on the sheet is reached. Data relating to that item is then keyed-in.