Google
 
Trailing-Edge - PDP-10 Archives - BB-J939B-BM - binary/reg2lb.mac
There are 3 other files named reg2lb.mac in the archive. Click here to see a list.
DEFINE TYPE,
    <
    PUSHJ
    TOPS20
    LINKAGEREGS <15,13,1>
    PRESERVE <0, 6, 7, 8, 9, 10, 11, 12, 14>
    NOPRESERVE <2, 3, 4, 5>
    >