Path: utzoo!mnetor!uunet!husc6!cmcl2!nrl-cmf!ames!ucsd!nosc!tetra!budden From: budden@tetra.NOSC.MIL (Rex A. Buddenberg) Newsgroups: comp.os.cpm Subject: Re: Determining TPA Requirements of Programs Message-ID: <681@tetra.NOSC.MIL> Date: 1 May 88 21:41:02 GMT References: Reply-To: budden@tetra.nosc.mil.UUCP (Rex A. Buddenberg) Organization: Naval Ocean Systems Center, San Diego Lines: 14 Checking before you run a program to see if there is enough TPA may not be enough by itself. Consider a program that allocates itself both stack and heap space. Typically, the stack space is static and resides right above the code itself. Heap usually starts just below all the CPM stuff in high memory and works down. And heap is usually data driven -- you can't know how much data there will be at program design time. Early Pascal compilers for CPM were great fun to watch when you could cause a heap/stack collision (i.e. run out of TPA) which would send everything off into the weeds -- correctable only by a cold boot. Rex Buddenberg