I saw that there's a SysIII bj.s, which is almost identical to the 2.11 one; so the latter is probably descended from the first, which I assume is Bell source. So I grabbed it and tried to assemble it. The errors are because bj.s is designed to be assembled along with another assembler source file, which contains the following routines which are missing from bj.s: mesg decml nline Dunno if you're aware of this, but, the line 'as a.s b.s' _doesn't_ separately assemble a.s and b.s, rather it's as if you'd typed 'cat a.s b.s > temp.s ; as temp.s'. (This is used in the demi-enigmatic "as data.s l.s" in the system generation procedure.) I looked around in the sources that come with V6, and I didn't see any obvious such file. I'm going to whip the required routines up really quickly, and see if the results assemble/run. I looked to see if I could steal them from the binary of 'bj' on V6, and... it looks like that binary is totally different from this source. Let me look into this... The V6 assembler groks '.even'. Noel