On 10/29/2016 07:11 PM, Fred Cisin wrote: > Can't help with that right now. Sorry. Simplest test for MS-DOS > 1.25 would the the dates of the files, particularly IO.SYS and > MSDOS.SYS. IIRC, 1.25 would be in 1982, maybe June. 1.25 was licensed for OEM customization for quite some time, so dates could well be later, depending on the OEM. --Chuck