Despite all the versions you see on the download page, there is only one official and original binary known of the MOS TECH BASIC for the 6502 KIM and that is my V1.1 (ID 01) loaded from my original tape. There is another tape known recently, owned by my friend Gerben Voort, and we hope to be able to read that tape.

Every other version is a derivate, in the 80ties or in the past years.

There are also sources of Microsoft Basic for the 6502. The official source, in PDP-11 MACRO source format has been declared open not so long ago.
The title is ‘M6502 8K VER 1.1 BY MICRO-SOFT’. Yes the name of the company was originally MICRO-SOFT!

Many years before the official source, Michael Steyl of pagetable.com reconstructed the source, based upon my binary dump. A perfect start to create derivate versions!

Versions known in the 80ties

• KB-9
  Created by Microsoft, only distributed by Johnson Computers (afaik). Binary available.
  On the tape label: 2000-4260 ID #01 St 4065
  Oldest known documentation available, scanned.
• KB-6
  Mentioned in the documentation of ID #01. Not available.
  6 digit precision floating point, smaller in size.
• KB-9 ID #101
  Distributed by Johnson Computers
  On the tape label: 2000-437D ID #101 St 4065 S/N 217 and 233. Binary not available (yet).
  Mentioned in the documentation of the versions distributed by Johnson Computer with ID #101. Binary not available. Two versions of the documentation known and scanned.
  This version seems to be the V1.1 KB-9 with added Hypertape and BLOCKMOVE routines at the end of the binary. With the alternative start addresses the hypertape routine can be moved to $0200 or $0300 and the SAVE command patched to the hypertape routine. Or with the standard start at $4065 hypertape can be skipped.
  All KB-9 internal addresses are the same.
• KB-9P
  Mentioned in the documentation of the versions distributed by Johnson Computer with ID #101, Binary not available.
  KB-9P is a stripped version of KB-9 fit for burning into a ROM. SIN-COS-ATN is not available.

My MSBasic for the KIM-1 cassette

Another MOS TECH BASIC for KIM-1, lower serial number

Thanks Gerben Voort