Path: utzoo!utgpu!water!watmath!clyde!bellcore!decvax!ucbvax!pasteur!ames!husc6!linus!philabs!micomvax!ray
From: ray@micomvax.UUCP (Ray Dunn)
Newsgroups: comp.lang.misc
Subject: Re: Languages and learning (was: Philosophy of C)
Message-ID: <903@micomvax.UUCP>
Date: 8 Feb 88 18:15:07 GMT
References: <11348@brl-adm.ARPA> <3473@ihlpf.ATT.COM> <3487@ihlpf.ATT.COM>
Reply-To: ray@micomvax.UUCP (Ray Dunn)
Organization: Philips Electronics Ltd. (TDS - Montreal) Montreal, Canada
Lines: 20
Posted: Mon Feb  8 13:15:07 1988

In article <3487@ihlpf.ATT.COM> nevin1@ihlpf.UUCP (00704A-Liber,N.) writes:
 > ....  About 7 years ago, I disassembled the BASIC ROMs on my TRS-80 Model I
 > I noticed a curious piece of code (which I will pseudocode here):
 >
 > 0998	LOAD	(C), 0
 > 1000	LOAD	(AB), 0112
 > 1003	LOAD	(AB), 0212
 > 1006	LOAD	(AB), 0312
 > 1009	real stuff
 > ....
 > They were taking advantage of the fact the the 12 in 12xx in the operand
 > field was also the operator for LOAD (C)!  They were jumping in to the
 > middle of instructions ...

Without examining it too closely, it seems to me that it is MUCH more likely
that you are disassembling on the wrong boundaries than the code is jumping
into the middle of instructions!!  Interpreting binary dumps can be VERY
misleading!

Ray Dunn.  philabs!micomvax!ray