readme

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

the latest version of spin is always
available via:
	http://spinroot.com/spin/whatispin.html

to make the sources compile with the mkfile on plan 9
the following changes were made:

	omitted memory.h from spin.h
	changed /lib/cpp to /bin/cpp in main.c
	simplified non_fatal() in main.c to remove
	use of yychar