RISC

/prog/, I'm working on a RISC instruction set that is more RISC than any RISC out there. I've devised an instruction format, plus fifteen core instructions that should suffice for any programming out there. The instruction format, instruction forms, and instructions can be found here:

http://jsbin.com/ekuwap

Any comments or suggestions?

Signal_code a=0 [Plus eight bit?]
|a|/Opcode a
...|aa|/Opcode b
......./[bbb]/

Could Easily keep expanding like this..?

Signal_code a=1
|a|/Signal_code b=0 [Plus another 8 bit?]
...|b|/Opcode c?
....../[cc]// Opcode D?
.........../[dddd] (one byte of signals//two bytes to spare..?)

mnemonic pushPageVal |1|0|00|0001| source Reg[5 bit] | dest L1[8 bit] ?

mnemonic popPageVal |1|0|00|0001| dest L1[8 bit] | source Reg[5 bit]