On Sat, Jul 13, 2024 at 1:35 PM John R Levine &lt;johnl(a)taugh.com&gt; wrote: Oops, it appears that I inadvertently forgot to Cc: COFF in my earlier reply to John. Mea culpa. For context, here's my complete earlier message; the TL;DR is that Honeywell was doing binary translation from the 1401 to the H-200 sometime in 1965 or earlier; possibly as early as 1963, according to some sources. -->BEGIN<-- Honeywell was doing it with their "Liberator" software on the Honeywell 200 computer in, at least, 1966: https://bitsavers.org/pdf/honeywell/series200/charlie_gibbs/012_Series_200_… (See the section on, "Conversion Compatibility."). Given that that document was published in February of 1966, it stands to reason work started on that earlier, in at least 1965 if not before (how much earlier is unclear). According to Wikipedia, that machine was introduced in late 1963; it's unclear whether the Liberator software was released at the same time, however. Ease of translation of IBM 1401 instructions appears to have been a design goal. At least some sources suggest that Liberator shipped with the H-200 in 1963 (https://ibm-1401.info/1401-Competition.html#UsingLib) It seemed like what Doug was describing earlier was still source->binary translation, using some clever macro packages. -->END<-- - Dan C.