There are 3 types of pn code generators in use at the observatory: . pncmem: pncode with 64k mem. pnclong : long code generator 2^39-1 length. pn128: pncode with 64K mem and 128K codes. ... schematic ip memory code generator(.pdf) . schematic ip memory code generator - cable . pal equations (.pdf) . ... schematic long code buffer board (.pdf) . ... This generator was created from a spare pncode memory board in mar05. ... pn128 start starts the pncode going. it ignores any starting phase . ...