Frank van Riet <Fvanriet@spescom.com> wrote:

A stack pointer (for instance) is an unsigned value the size of a machine word -period.

Just a quick hint. To compare two stack addresses a, b: LONGINT, you could use: SYSTEM.LSH(a, -2) < SYSTEM.LSH(b, -2), since the addresses are always multiples of 4. LSH is a logical (unsigned) shift. -1 instead of -2 will also work. This is much more text than a, b: CARDINAL and a < b, but the code is not significantly slower on a modern processor. Defining an inline UnsignedLess(a, b) CODE procedure is also an option, but is not portable to non-Intel ETH Oberon systems. BTW Someone mentioned that the bit order of SET is implemented differently in different compilers. This was the case with the PowerPC compiler, but in the meantime Günter Feldmann has fixed this. If you use the latest releases, in low level code you can now assume that SYSTEM.VAL(LONGINT, {0}) = 1 on all current ETH Oberon systems. -- Pieter -- Pieter Muller, Computer Systems Institute, ETH Zurich / MCT Lab, Zurich Native Oberon OS: http://www.oberon.ethz.ch/native/