On Feb 1, 2023, at 11:59 AM, Sellam Abraham via cctalk <cctalk@classiccmp.org> wrote: > > On Wed, Feb 1, 2023 at 11:45 AM Fred Cisin via cctalk <cctalk@classiccmp.org> > wrote: > >>> On Wed, 1 Feb 2023, Zane Healy via cctalk wrote: >>> So far I’ve tackled one split zip. I wasn’t having any luck with >>> the version of PKZIP that I assume created this. I copied the files >>> into a directory, and did COPY >>> FILE1.ZIP+FILE2.ZIP+FILE3.ZIP+FILE4.ZIP+FILE5.ZIP COMBINED.ZIP >> >> THAT will give you a corrupted file! >> >> Concatenated copy (COPY with '+') has a behavior that you need to take >> into account. >> >> PC/MS-DOS 1.00 kept track of the file size with a course granularity. >> (logical sectors, not bytes) >> Therefore, PC/MS-DOS supported CTRL-Z as an end of file character! >> (A legacy of CP/M) >> >> When you cop a file, it copies the whole thing. Any extraneous content >> after EOF won't matter. >> >> BUT! When you concatenate files, >> COPY FILE1.ZIP + FILE2.ZIP COMBINED.ZIP >> COPY will terminate FILE1.ZIP at the first CTRL-Z that it encounters! >> When copying text files, Concatenated COPY will trim off all content after >> EOF! >> It is called "text mode". >> >> You need to change your command to >> COPY /B FILE1.ZIP+FILE2.ZIP+FILE3.ZIP+FILE4.ZIP+FILE5.ZIP COMBINED.ZIP >> to get "binary mode", so that it will copy ALL of each file, rather than >> just to the "end of file character" of each! >> >> Compare the final resulting file size of COPY and COPY /B >> >> -- >> Grumpy Ol' Fred ci...@xenosoft.com > > > Excellent knowledge transfer, Fred. That is what makes this list great. > > Sellam
You have that right Sellam, the more that I look into this, based on Fred’s info, I think that I need to get MS-DOS running under DOSBOX-X. Zane
