Abstract: A personal computer such as one of the IBM 5550 range (represented by the IBM 5530, 5540 and 5560) cannot be connected to a label printer because the two machines have completely different control commands. If a converter is placed between a personal computer of the said type and the label printer, the converter can convert or arrange the data, loop-back anh meaningless or unsuitable signals passing between the two devices, and discard any unnecessary control commands, thus permitting personal computers of the above type, which are increasingly popular, to be connected to a label printer and used effectively, and further permitting the online printing of tags and labels via a connection to a host computer.