* [[Media:SPR-128 Newer.pdf]] - external 128Kbit ROM preliminary 24pin package with defined pinouts
* SPB640 - external speech fifo
* US Patent 4,296,279 - might cover the SP0256 (or rather the old SP0250) (not sure, it's in cryptic patent language)
* http://spatula-city.org/~im14u2c/intv/tech/sp0256_instr_set.html - reverse engineered instruction set by 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]]