Connect HP41 to Apple

[hesc]

LS,
I wrote a lot of programs for my old HP41CV (which is dead since yesterday, 44 years old…, but I have a second one) and had some experience to copy these programs, making use of an HP-IL HP41 interface and a so-called Pil-box. For that purpose, I made use of a file transfer program Ilper.exe. The transfer was not very stable, because sometimes it did not recognize COM 5 (my USB, I believe) and also gave an error at the end sometimes.
However, some years ago I was successful in transferring programs in that way and used a file conversion program named HP41UC. I made notices of it and made the use of option /l to /t, i.e. *.lif to *.txt. For some reasons that does not work anymore, but I still had the *.dat file from the original file transfer and a *.txt file from the conversion result. In the meantime I looked at the *.dat file and copied it to a *.BIN file and a *.RAW file. In that case the transfer to the *.TXT file worked, but with some typical headers.
Question to you is:
What is the original file format resulting from the HP41 to HPIL transfer and what kind of headers are connected to the raw and bin format?
Do you have an idea why the transfer is not very stable? Do you think there is a mismatch in serial? Settings or so?
Now, I am using an older Windows computer. The *.exe work under a DOS environment. I tried a parallel desktop with windows 11 on my Mac Studio, but then the *.exe do not work. Has someone an idea how to solve these problems?
Sorry for the long intro… Hope you have time to answer…
Kind regards,
Henk Schellen