Mmm... clearly a marginal case (derive it to another thread if you consider it opportune), but... I got one PDP-11/23-PLUS without any kind of disk (by now, I got one RL12 board plus one RL02 drive pending of cleaning and arrangement)... I guess if could be possible to run V6 in this machine. There's any kind of adaptation of this Unix version (or whatever) to run under ? Kind regards Saludos | Greetings | Freundliche Grüße | Salutations ​ -- *Sergio Pedraja* -- mobile: +34-699-996568 twitter: @sergio_pedraja | skype: Sergio Pedraja -- http://plus.google.com/u/0/101292256663392735405 http://www.linkedin.com/in/sergiopedraja http://www.quora.com/Sergio-Pedraja http://spedraja.wordpress.com https://www.xing.com/profile/Sergio_Pedraja ----- No crea todo lo que ve, ni crea que está viéndolo todo 2014-05-12 19:06 GMT+02:00 Noel Chiappa : > > From: John Cowan > > > Well, provided the compiler is honest, contra [Ken]. > > A thought on this: > > The C compiler actually produces assembler, which can be (fairly easily) > visually audited; yes, yes, I know about disassembly, but trust me, having > done some recently (the RL bootstrap(s)), disassembled code is a lot harder > to grok! > > So, really, to find the Thompson hack, we'd have to edit the binaries of > the > assembler! > > For real grins, we could write a program to convert .s format assembler to > .mac syntax, run the results through Macro-11, and link it with the other > linker... :-) > > > Also, I found on what's going on here: > > > What was wierd was that in the new one, the routine csv is one word > > shorter (and so is csv.o). So now I don't understand what made them > the > > same sizes!? The new ones should have been one word shorter!? Still > > poking into this... > > The C compiler is linked with the -n flag, which produces pure code. What > the linker documentation doesn't say (and I never realized this 'back in > the > day') is that when this option is used, it rounds up the size of the text > segment to the nearest click (0100). > > So, in c2 (which is what I was looking at), the last instruction is at > 015446, _etext is at 015450, but if you look at the executable header, it > lists a text size of 015500 - i.e. 030 more bytes. And indeed there are 014 > words of '0' in the executable file before the data starts. > > And if you link c2 _without_ the -n flag, it shows 015450 in the header as > the text size. > > So that's why the two versions of all the C compiler phases were the same > size (as files); it rounded up to the same place in both, hiding the > one-word > difference in text size. > > Noel > _______________________________________________ > TUHS mailing list > TUHS at minnie.tuhs.org > https://minnie.tuhs.org/mailman/listinfo/tuhs > -------------- next part -------------- An HTML attachment was scrubbed... URL: