[pups] 2.11BSD "make unix" aborts Error 141

Steven M. Schultz sms at 2BSD.COM
Thu Mar 20 03:46:51 AEST 2003

Hi -

> From: David Evans <dfevans at bbcr.uwaterloo.ca>
>   Ugh.
>   Am I naive to suggest a rewrite of as?  :)

	Just a little bit <g>

	It's a thought that used to occur to me fairly often a long time 
	ago.  I cured myself of it though after I did the rewrite into
	its current form (if you think it's bad now you should have seen it
	before ;)).

	The biggest problem are the SDI (Span Dependent Instructions).  The
	PDP-11 has 'jmp' (non conditional but no range limit) and 'br' (many
	flavors of conditional branches but with a +/- 128 byte range).  
	The compiler generates pseudo instructions like 'jeq' and leaves it
	up to the assembler to figure out if a branch will reach or if a
	branch around a jump is needed.   That's a PITA to handle and is
	I believe the cause of much ugliness in the assembler.

	So I'm fought the urge to rewrite the assembler and 'won' - I no longer
	feel the rewrite urges ;)

	Steven Schultz

More information about the TUHS mailing list