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HP 75 - GLOBALS file anyone?
12-02-2016, 03:07 PM
Post: #15
RE: HP 75 - GLOBALS file anyone?
(12-02-2016 01:48 PM)rprosperi Wrote:  ... I'm not even sure how 75 LEX files were built back in the day; as far as I recall, there were no HP tools provided, the only option being a BASIC program to 'POKE' the hex (octal?) bytes into RAM.
Bob,

so far I have seen three main methods to create LEX files for the HP 75, all running on the HP 75:
  1. Entering HEX bytes into a file (either POKEing directly into a HP 75 memory file or writing to a 82161 cassette) and setting the file type/access bits to "LEX".
    HEX listings for a few LEX files can be found e.g. in Datafile or the PPC journal. The drawback is that only the HEX bytes were printed and no assembler input file. This was the most common method, suitable for everyone without the need to have an assembler. Just a BASIC program, a POKE LEX file and often the I/O ROM.
  2. Using a RAM based Forth system with an assembler written in Forth. While this shows the power of the Forth system the drawback is that the Forth words used make the input file read a bit funny compared to what one is used from the S-80 assembler. But close and much better than just having HEX bytes.
    Also free memory was very limited, only suitable for small LEX files.
  3. Using a BASIC program (e.g. ASM75 or one that was sold by W&W in Germany). Here "real" mnemonics can be used, close or identical to the S-80 assembler syntax.

All these methods use the tight RAM of the HP 75 and often required the purging of intermediate files or swapping programs.

So far I have not read anything about people using external development tools (like my S-80 assembler approach).

Also I am not sure whether HP provided any development tools (except some for the module emulator). They obviously used HP 1000 systems with their KARMA assembler, probably the same setup as used for on-house S-80 development work.

Martin
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RE: HP 75 - GLOBALS file anyone? - Martin Hepperle - 12-02-2016 03:07 PM



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