|HP75C/D vs. HP-71B|
Message #6 Posted by Valentin Albillo on 30 July 2007, 7:30 p.m.,
in response to message #4 by Howard Owen
I also had an HP-75C at the time it was released, and was able to use it a little and write programs for it, then the HP-71B was released as well.
The HP-75C had some very good things when compared to the HP-71B but ultimately many shortcomings as well, for instance:
- Good: an 8-bit Capricorn CPU, the same as the HP-85, which I already knew how to program directly in Assembler. Matter of fact, many of the internal routines were taken directly from the HP-85 internal ROMs, with nearly the same inputs and outputs, so I already could make sense of them. And it was pretty fast, nearly as fast as the HP-85 itself.
In contrast, the HP-71B had a new 4-bit Saturn CPU, which was a mistery to me at the time, and it was nearly 5 times slower than the HP-75C's.
- Good: larger display, nice and wide keyboard, versus the utterly insufficient 71B display and small, calculator-like keyboard.
- Bad: very large and heavy, required a briefcase at the very least and considerable tabletop room.
- Bad: Very little RAM, even with expensive add-ons such as the Pod, versus the 512 Kb address space of the HP-71B, which was enormous by the usual standards back then (16 Kb, 32 Kb, 64 Kb, ...)
- Bad: No PEEK/POKE built-in, which made LEX-programming bootstrap impossible. You needed a PEEK/POLE LEX somehow before you could do anything of the sort. On the other hand, you could enter LEX files on a bare-bones HP-71B with a program using just standard instructions.
- Bad: The all-important Math ROM functionality and design couldn't hold a candle to that of the HP-71B, most specially regarding complex number dimensioning and functionality.
- Bad: The BASIC dialect of the HP-71B was much better than the one in the HP-75C in many important aspects, and with the exception of the so-called IO ROM, the HP-71B had better ROMs and peripheral capabilities.
Best regards from V.