Had the #LEGO Technic #Barcode 8479 Set / Technic Truck / Code Pilot when I was young. It's sometimes referred to as the LEGO #Mindstorms' predecessor, released in 1997. Did you also have one?
It was probably way cheaper than Mindstorms, but also less capable. I just got the Code Pilot from eBay recently (and other programmable bricks). A nice — maybe not yet obsolete — universe.
Looking for some #reverseengineering docs. And I'd also like to know if the barcode encoding fits some standard.
Seems to match:
"VLL is a binary bar code comprised of: Start bit, Checksum, Data, Stop bit. (...) The checksum and data are binary digits with 0 being two spaces and a bar while 1 is a space and a double width bar. The checksum is 3 digits and the data is 7 digits. The data is the VLL code from 0 to 127. To determine the checksum for VLL code n in C or Perl: 7-((n+(n>>2)+(n>>4))&7)"
Source: https://www.elecbrick.com/lego/
Exemplary checksum calculation VLL for piano command "C1 Note" (099). The barcode shows 0b110'1100011. The leftmost (=most significant) bits represent the checksum bits. In this example: 0b110 = 6d. The payload bits are 0b110'0011 which is 99 in decimal.
Checksum calculation:
7-((99+(99>>2)+(99>>4))&7)=
7-((99+24+6)&7)=
7-(129&7)=
7-(0x81-0x07)=
7-1=6=0b110
Valid barcode! :)
BTW VLL stands for Visible Light Link wich is also used by the #LEGO #MicroScout. Some scripts for VLL? Find here: https://github.com/JorgePe/mindstorms-vll
People have also used VLL to control the MicroScout from an RCX: https://pbrick.info/index.html-p=45.html
And some final(?) remarks about VLL:
https://pbrick.info/index.html-p=58.html provides an "NQC library to enable a LEGO RCX to send Visual Light Link (VLL) commands to a LEGO MicroScout"
Talking VLL (from the Scout) to the Micro Scout:
"If you have a Scout, the easist way is to get the SDK and have the Scout talk to its little brother."
http://www.elecbrick.com/vll/
This site also includes a link to the postscript "MicroScout VLL Bar Code Generator" with a lot of comments. PDF version also available for download.
Mäh W.