LISP I Programmer's Manual - Software Preservation Group

Errors due to computer inadequacies:B1 OUT OF PUBLIC PUSH DOWN LIST -SAVE-1.e. the program has run out of space allotted to thepublic push-down list .' Currently about 1000 registersare allotted, and, if they are used up, the recursionI Ibeing done is either too deep" for the given capacity ornon-terminating.B2 FREE STORAGE COUNTER PANIC STOP. PRESS START TO CONTINUEThere is a free storage counter, called the "CONS counter",associated with the LISP system. Every time a register istaken from free storage, the counter is increased by one,The counter is not changed by the garbage collector operation.Thus to some extent the counter indicates how a programis operating--how much storage it is using, and so on,or, for a program whose operation is known, how long it hasbeen running. The counter is initially set to zero, andwhen it has reached 100,000, the computer stops after givingthe error print out B2. When the start button hasbeen pressed to restart the computer the counter continuescounting, but no further stop occurs,B3 DIVIDE ERROR -OCTAL TO DECIMAL CONVERTER-This error arises only when the computer malfunctions orwhen some of the program has been written over.1See page 144 of the Quarterly Report referred to on the firstpage of Chapter 2.