Simple one instruction language; type of OISC; specifications from Clive Gifford eigenratios self-interpreter page. Each subleq instruction has 3 operands which are memory addresses. Oleg Mazonka.
By Philip J. Koopman, Jr; Ellis Horwood, 1989, ISBN 0470214678. Read on-line, or download in formats: HTML, PDF, zip file. First book to explore a new breed of stack computers led by introduction of Novix NC4016. [Free]