IBM 702/705/7080 Programmers Model

The 702 was designed to be the business counterpart to the 704. The 705 was the upgrade to the 702, but it was not 100% source compatable. The machines had two accumulators that were 256 characters (512 for the 702) long and in a ring structure. On the 702 the accumulators were identical. On the 705 and 7080 accumulator B was divided into 15 sections. All instructions were 5 characters long, one character opcode and 4 character address.

The operations were as follows:

OpcodeCodeNote
ADDAddG 
AAMAdd Address to Memory@7080
ADMAdd to Memory6 
BLMBlank Memory$7080
CMPCompare4 
CTLControl3 
CTL2Control,7080
CTL3Control)7080
DIVDivideW 
HLTHaltJ 
LNGLengthenD 
LODLoad8 
LDALoad Address#7080
MPYMultiplyV 
NOPNopA 
NTRNorm and TrX 
RADReset AddH 
RCVReceiveU705
RDReadY 
RNDRoundE 
RSUReset SubtractQ 
RWWRead while WritingS 
SBZSet bit%7080
SELSelect2 
SETSet leftB 
SGNSignT 
SHRShortenC 
SMTTransferTRM 
SNDSend/ 
SPRStore for print5 
STStoreF 
SUBSubtractP 
TMTTransmit9705
TRTransfer1 
TRATr AnyI 
TRETr EqualL 
TRHTr HighK 
TRPTr PlusM 
TRSTr SignalO 
TRZTr ZeroN 
TZBTr Zero Bit. 
ULAUnload Address*7080
UNLUnload7 
WRWriteR 
WREWrite EraseZ 

The 7080 adds in some extra opcodes under the CTL, CTL2 and CTL3 codes. These opcodes use the register encoding to select the opcode to do.

OpcodeCodeRegNote
ECBEnable Backward compare3127080
CHRClear IO Error3137080
EEMEnter 80 mode3147080
LEMLeave 80 mode3157080
SPCSet Starting Point,07080
LFCLoad four chars,27080
UFCUnload four chars,37080
LSBLoad storage bank,47080
USBUnload storage bank,57080
EIMEnter Interrupt Mode,67080
LIMLeave Interrupt Mode,77080
TCTTransfer 10 chars,87080
EIAEnable Indirect address,107080
CNONop,117080
TLUTable Lookup Equal,127080
TLUTable Lookup Equal or high,137080
TIPTr to Interrupt program,147080
LIPLeave Interrupt program,157080
TRCTen char recieve)87080
SMTStore Ten zero)147080