Hello,
I got my hands on an 8662A verification tape. I posted the booklet/manual that came with it in the files section (
/g/HP-Agilent-Keysight-equipment/files/8662A).
I do not have the 9825 controller to read the tape. It may not be readable at all due to age. From the outside, it appears to be unused.
Anyways - if anyone has the means to read the tape, please let me know and I will send it to you (US preferred to limit shipping expense). The only ask I have is - if feasible - to post the contents/files in this forum. I do not know whether these programs are stored in a binary format that will only work for a 9825 or in a higher-level programming language that could be converted to a different platform (e.g. HP Basic on HP9000/300).
Regards,
Wolfgang, KI7PFX