Check this guy out!

[Nigel (UK)]

(10-29-2024 02:46 PM)Commie Wrote:  ...
The best is bcd floats because they are transparent to i/o or strings and here is the problem, all the compilers, that I have seen or made aware of either use ieee 754 32 or 64 bit binary floats. This is done intentionally to stop would be good calculator design and protects the lower end of the existing scientific calculator market. So the only option open is to go assembler and try and mix the software with a standard high level compiler, avoiding the ieee 754 floats. A big help would be to have access with 64 bit integer data type support but the one compiler (that I have seen) that supports this, costs about $1500.

One way of doing this is to do what the calculators written for the DM42 hardware do, and that is to use a library that offers decimal arithmetic - decNumbers and the Intel decimal library are the two that I'm familiar with, but I'm sure there are others. (The latter is the faster of the two but takes up much more flash memory, due to use of lookup tables. Free42 uses the Intel decimal library; C43 and C47 use decNumbers; db48x uses a library that c3d wrote himself especially for that calculator!)

For this reason, I'm not sure about the "stopping good calculator design" theory. The WP34S ran on the HP 20/30b hardware (launched in about 2012). This had only a few kilobytes of RAM and 128k of flash memory for the firmware; it used decNumbers to deliver 16 or 34 decimal digits of precision, had a huge number of programming and mathematical functions, and still had about 10k left over for flash storage of user programs. If someone wants to build a calculator which supports decimal floats, they can do it - certainly if they have 128k of flash available.

Also, the GNU cross-compilers that build the pgm files for the DM42 certainly support 64-bit integers (at least for this target), and are of course freely available.

Nigel (UK)