🚀 go-pugleaf

>>>>> On 20 Dec 89 18:23:00 GMT, Greg_d...@mts.rpi.edu (Commander Krugannal) said:

Moore>      One program segment I have never tried, but supposedly works
Moore>    on at least the IBM 3081D, is the statement BALR 12,12.
Moore>    This instructs the assember to branch to 12 and load the value
Moore>    of 12 and exucute it. Well, the command 12 is BALR, so this 
Moore>    essentially tells itself to BALR to itself, and excute what is
Moore>    there, which is a BALR and you get the picture. :-)

It's been 20 years since I've written assembler, but you've been led
astray.  Branch And Link Register (BALR) is intended to facilitate
subroutine calls; it loads the address of the next effective pc into
the first register and branches to the address contained in the second
register and

a) that pc will be the one following the BALR
b) the destination address may well have been computed before the pc
   being stored (I don't recall the order of address evaluation) and,
   even so,
c) the data being stored is a pc, not the BALR instruction itself and,
d) the 360/370/etc series has a separate accumulator and memory space,
   so one cannot branch to a register.