Printer DIMMs & SIMMs: the hard way to format documents
In the early days of SAP, output was not fully composed, making formatted documents difficult to print. IT staff were forced to use special chips, called DIMMs or SIMMs, that contained fonts that were otherwise unavailable for printing. They would then invoke these fonts using special control codes built in to modified device types, or use standard PCL in some cases, to reference them. This approach was inconvenient, but it worked well enough to become a common technique.
Administrators are always hesitant to modify a system that works, so even after SAP introduced the ability to directly print bar codes to laser printers, many companies simply retained these DIMM and SIMM cards. However, as printer fleets evolved, modern hardware did not always have the required internal ports for these cards. Furthermore, modern document presentment systems made it easy and efficient to produce fully composed SAP output instead of relying on such cards.