I didn’t think anyone used octal any more.
That was definitely one for the cognoscenti, as it’s hardly obvious that the compiler likes to make multiple hex bytes but single octal ones.

But the compiler is happy with /260C. Unfortunately, we have to do a bit of rewiring in the product for an unrelated reason, so I’ll know in about an hour what shows up on the display.

Some of the old machines had 12/24/36-bit words that were dividable by three bits so octal use was common in programming.
If you use Linux or Unix, octal literals are what's used for file permissions, are an option for IP addresses and are used in several old utilities, so C and it's libraries have a special place for them.
https://www.ibm.com/support/pages/i...value-when-ip-address-specified-leading-zeros
IP Address Converted To Octal Value When IP Address Is Specified With Leading Zeros

Try: ping 00000000000000000000000000000000000000000000000000177.0.0.01


The real reason the US didn't go metric.
https://ieeexplore.ieee.org/document/1671900
Adoption of the Octal Number System

Abstract
The possible adoption of the metric system in the United States makes it logical that any other major changes be considered at the same time. Therefore, it is proposed to adopt the octal number system in place of the decimal. The importance of computers in our lives makes it reasonable that we adopt a number system with a base 2n. The advantages and disadvantages of the various values of n are given. The octal (n=3) number system is found to be the best one. The feasibility and some ramifications of octal adoption are presented.

 

Hurrah for octal!