Paul, I'm surprised that copies of the LSX system are still around.
I'm assuming that you acquired only the binary code, and not the
source code. The LSX system source code could be compiled
on an LSX system running on floppy disks. I see you are getting
your C compiler issues addressed by others already.

Heinz Lycklama
Author of LSX at Bell Labs

On 5/30/2020 11:26 PM, Paul Riley wrote:
I've managed to acquire a PDP-11/03 with twin floppy drives (Sykes Datatronics RX01 or RX02 equivalents, not sure yet which).

I've stumbled across LSX, and I have it running on SimH. I'm quite inexperienced with Unix, but it's something I want to learn well, having brushed against it at university in the '80s, and having played with Linux somewhat.

I have some interest in Forth, but I don't like the block system of early forths such as FigForth, and I plan to create a new Forth based on FigForth, but supporting external source files.

Anyway, I've tried compiling Hello World on LSX, and I get "1: External definition syntax" error. Some help would be nice, but more generally, is anyone on this list more than vaguely familiar with LSX, or 6th Edition itself?

void main () {
        printf("Hello World!");
}

It seems that the 7th Edition was the beginning of the standard library in C, and that this is missing in LSX. I'm not sure if printf is an intrinsic function in (6th Edition) C, or if it's from a library.

My questions are a bit random, but looking to converse with others with LSX experience.

Paul

Paul Riley