Ah ha! The file format is the “GEnie format”[1] and was apparently generated by Joe Fugate and uploaded to the GEnie Information Service (if you remember that service, and I do FWIW, you have just dated yourself!). 🤣

Just not sure why the file has a ‘.vmb’ extension and it doesn’t answer the question of C0.  🤔

[1] “Sector Data File Formats — The Traveller Map”, https://travellermap.com/doc/fileformats

> On Nov 8, 2023, at 7:45 PM, Chuck McKnight - chuckmcknight at pheonic.com (via tml list) <xxxxxx@simplelists.com> wrote:
>
> Sadly no. I remember seeing the format before though I can’t put my finger on where.
>
> Sent from my iPad
>
>> On Nov 8, 2023, at 7:02 PM, Jeff Zeitlin <xxxxxx@freelancetraveller.com> wrote:
>>
>> On Wed, 8 Nov 2023 18:45:44 -0600, Charles McKnight wrote to Freelance
>> Traveller:
>>
>>> Sorry, I grabbed the wrong email address for you. :-(
>>
>> The file is indeed pure text, and I've seen that format before - if I'm
>> remembering correctly (memory is the second thing to go), that was more
>> often seen as "Sunbane SEC format", and I believe that JimV even included a
>> converter (SEC2GAL) that would automassage it into a sector (sixteen
>> subsectors) for his GALACTIC program (which, I should note, runs perfectly
>> well under DOSBox, including AFreeBox on Android).
>>
>> It would not surprise me if "VMB" stood for "Virtual Map
>> B...«something-or-other»".
>>
>>
>>
>>
>> ®Traveller is a registered trademark of
>> Far Future Enterprises, 1977-2022. Use of
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>>
>> --
>> Jeff Zeitlin, Editor
>> Freelance Traveller
>>   The Electronic Fan-Supported Traveller® Resource
>> xxxxxx@freelancetraveller.com
>> http://www.freelancetraveller.com
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