The USSC90, the codecard.

The first side 

displays three tables of addresses in the memory,
to or from these patterns the data was 
read or written from/to the buffers.  
These buffers interfaced with the printer, 
the card-reader and the read-punch unit.







The second side

displays a table with the codes for the 39 instructions. 
This table cdisplays six columns;
- The numeric-code of the instruction,   
- the meaning of M,  the operand-address, 
- the meaning of C,  the address of the next instruction, 
- the description of the the action,   
- the time needed for these instructions and 
- pointers to the notes.






The third side 

displays 
- the notes, 
- the abbreviations and 
- the special bit-patterns to address the registers.






The fourth side

displays two tables 
with the bit-patterns of the  machine-code and of the RR-code,
 referring to the results of the two translating-instructions.
And one table with the values of odd bit-combinations.

















These codes were specific for the USSC90,
the USSC80 used differend A/N-codes.