• In the 1980s, the author bought an HP 16C programmer's calculator and found it useful for programming an HP3000 mini computer as it had various bit operations and was programmable.
• The HP3000 used octal for bit display and docs were in octal. On machines with a word size as a multiple of 3 bits like the Dec-10, characters were often represented as six-bit. In Dec-10's COBOL, six-bit was efficient with 6 characters per word.
• Using octal on 8-bit byte machines was a pain. On a 'modern' 16-bit machine, hex is used to represent a word. Each hex digit is 4 bits. The HP3000 used octal, so instead of seeing 0x4142, it showed 040502.
• The ASCII Character Set from the HP3000's MPE Software Pocket Guide had no reference to hex. To read an ASCII string from an octal dump, one had to use a table. The author had a program in the HP 16C to convert octal to bytes.
• Towards the end of the HP3000's lifespan, HP started making it easier to use hex but the author was in the networking world by then.
• Texas Instruments had a competing calculator called the TI Programmer which was less expensive and had fewer capabilities.
• After the short HP 16C run, HP didn't make another programmer's calculator. The author put the HP 16C in a drawer and it remained there for 30 years except for a small ding. It is now worth around $300 on eBay and the author is reluctant to sell it.
• The author wondered if there was a phone app emulation and found a nice android phone emulation. It seems to do everything and the author played with it for an evening but didn't try writing a program. More information about the emulation can be found at [https://jrpn.jovial.com/], and the original manual at [https://archive.org/details/h...]. If one needs to do a lot of bit manipulation, it is recommended to look at this emulation as it is more enjoyable than the Microsoft Calc program.