Pretty sure it does stop, if it runs out of addend and there’s no carry. Dave Wise
> On Jan 15, 2025, at 10:58 AM, Chuck Guzis via cctalk <cctalk@classiccmp.org> > wrote: > > On 1/15/25 09:49, Paul Koning wrote: > >> Yes, it certainly had that feature. I'm not sure about the limits, I >> thought the integer limit was 99 digits. The reason for these options is >> that it's directly supported by the hardware, which has arbitrary length >> integers and (up to a limit I forgot) floating point mantissas. Given the >> encoding in the hardware, it makes sense that you could mix and match; the >> hardware would accept operands of whatever size you pick, in whatever >> combination you like. So, for example, adding a 3 digit integer to a 300 >> digit integer would work just fine. > > Looked up the latest 1620 FORTRAN reference in the Monitor II-D manual. > 10 and 28 for FANDK, so my memory isn't completely gone yet. > > Always wondered if addition and subtraction on the 1620 had a > "shortstop" implementation. For example, adding a 10 digit to a 50 > digit number, would the operation stop if there was no carryout after 10 > digits, or would the implementation process all 50 digits? > > --Chuck > >
