* SPB640 - external speech fifo
* US Patent 4,296,279 - might cover the SP0256 (not sure, it's in cryptic patent language)
* http://spatula-city.org/~im14u2c/intv/tech/sp0256_instr_set.html - reverse engineered instruction setby Joe Zbiciak and Frank Palazzolo (caution: this doc has the opcodes in same bit-order as Target values, which is probably not the way how it was originally intended. In practice it makes no real different, except that the opcode summary looks more nicely sorted when "unreversing" the opcode bits)
[[Category:Programming]] [[Category:Hardware]]