Decimal Day and 10p coin equivalents, co-existed in circulation as valid currency until the early 1990s. In theory this included coins dating back to 1816; in practice the oldest were dated 1947, when these coins stopped containing silver. The coins were withdrawn when smaller 5p and 10p coins were introduced in 1990 and 1992 respectively. The face value of Maundy money coins was maintained, increasing all their face values by a factor of 2.4, as the coins continued to be legal tender as new pence. The numismatic value of each coin, though, greatly exceeds face value. The decimal halfpenny (p), introduced in
Decimal computer extended to wider formats and hence are now slower than using 32-bit or wider BCD 'tricks' to compute in BCD (see ). The x87 FPU has instructions to convert 10-byte (18 decimal digits) packed decimal data, although it then operates on them as floating-point numbers. The Motorola 68000 provided instructions for BCD addition and subtraction; as does the 6502. In the much later 68000 family-derived processors, these instructions were removed when the Coldfire instruction set was defined, and all IBM mainframes also provide BCD integer arithmetic in hardware. The Zilog Z80, Motorola 6800 and its derivatives, together with other 8-bit