SATURN BASIC for HP-48G/G+/GX, HP-49G and HP-49G+/50G

[HrastProgrammer]

Note: SATURN BASIC was initially called HRAST BASIC but I decided to rename it because this name suits the interpreter better as it really is the "BASIC for SATURN CPU" and was never planned for any other architecture. This name change happened after the release so I kept "HRAST" in filenames and URLs to avoid breaking the existing links.

***

It makes me very happy to announce the availability of my SATURN BASIC high-level programming language, interpreter and development environment for HP-48G/G+/GX, HP-49G and HP-49G+/50G calculators. This isn't really an ordinary BASIC as used to be on various home and pocket computers. It is inspired by BASIC but in many aspects it is more like Pascal, C, COMAL or Forth (internally). I've been working on it for quite some time and I have now come to the point where it is stable enough to be released to the public for the first time. This is the culmination of my work as far as HP/calculator development is concerned and I must admit that I am very proud of it. The final result is "the BASIC as I always wanted it to be" because I was never really satisfied with the choice of development tools available on HP calculators.

As far as I know, this is the first and only BASIC interpreter made for any HP calculator after HP-71B released in 1983. And this is the first and only BASIC interpreter developed outside Hewlett-Packard for any HP calculator ever. Those facts make me even more proud and happy

The first version was SATURN BASIC 32K because it should work on the basic HP-48G with 32K RAM only and after installing the emulator you can still (although barely) allocate a reasonable 8K of RAM for BASIC program and data. The feature set is fixed and no new features will be implemented for 32K version because I want it to stay under 20K. The final version is SATURN BASIC 48K which needs at least 48K of free RAM for normal work. Although I consider 48K version finished as well, there are still a few non-essential things left to be implemented if/when time permits.

Three main goals during the development were to make it as powerful as possible, to make it as fast as possible and to use as little memory as possible. Those goals don't usually go very well together so every time I had to choose between speed and memory - I choosed speed. Furthermore, I wanted everything to be limited by the available memory only - there is no fixed expression stack, no fixed GOSUB/FOR/NEXT and PROC/FUNC stack, expressions can be as complex as you want, you can call subprograms/procedures/functions as deeply as you want, you can have as many nested control structures as you want, etc, etc. This system is very complex but works great and the result is very powerful and fast BASIC interpreter, exceeding the speed and feature-set of even the most powerful home computers like, for example, Acorn BBC B which is well known for its great and very fast BASIC. And it is definitely much faster and much more powerful than all other BASICs on pocket computers and calculators. I made a lot of benchmarks and I will present some results here. The first benchmark is "8-Queens" problem as described on the following site:

http://www.hpmuseum.org/cgi-sys/cgiwrap/...i?read=700

SATURN BASIC running on HP-48GX finishes this benchmark in 16.4 seconds.
SATURN BASIC running on HP-49G+ finishes this benchmark in 7.2 seconds.

This makes it much faster than all other BASICs on this page except QBasic, Power, Turbo and Quick BASIC running on HP-200LX. The benchmark program is here, so you can get a picture how an optimized program for SATURN BASIC looks like (various strange details from this program will be explained throughout the manual):

Code:


CALL QUEEN,8
PROC QUEEN(INTEGER N) INTEGER A[N+1],D,S=1,X,Y A[1]=N
FOR X=2 TO N S> A[X]=N FOR Y=X-1 D=A[X]-A[Y]
IF NOT D OR X-Y=ABS D@ A[X]< WHILE NOT A[X]@ X< A[X]< ENDWHILE S> Y=X
NEXT NEXT ? A[1],A[2],A[3] ? A[4],A[5],A[6] ? A[7],A[8]

A little slower but more clear version of the same benchmark:

Code:


CALL QUEEN,8
PROC QUEEN(INTEGER N)
INTEGER A[N+1],D,S=1,X,Y: A[1]=N
FOR X=2 TO N: S=S+1: A[X]=N
FOR Y=X-1: D=A[X]-A[Y]
IF D=0 OR X-Y=ABS D@ {
_ A[X]=A[X]-1
_ WHILE NOT A[X]@ X=X-1: A[X]=A[X]-1: ENDWHILE
_ S=S+1: Y=X
}
NEXT: NEXT
? A[1],A[2],A[3]
? A[4],A[5],A[6]
? A[7],A[8]

I also executed all PCW home computer benchmarks (slightly modified for SATURN BASIC):

http://www.geocities.ws/peterochocki/com...pcwbm.html
http://www.geocities.ws/peterochocki/com...lcbms.html

REAL results for BM1..BM8 on HP-48GX are: 0.24s, 2.78s, 9.09s, 8.82s, 9.33s, 11.85s, 19.75s, 27.43s, Average = 11.16s

INTEGER results for BM1..BM8 on HP-48GX are: 0.24s, 1.78s, 5.58s, 5.64s, 6.14s, 8.66s, 15.83s, 26.64s, Average = 8.81s

REAL results for BM1..BM8 on HP-49G+ are: 0.07s, 1.97s, 6.03s, 6.08s, 6.41s, 7.75s, 11.70s, 17.92s, Average = 7.24s

INTEGER results for BM1..BM8 on HP-49G+ are: 0.07s, 0.73s, 2.37s, 2.49s, 2.81s, 3.99s, 7.49s, 16.83s, Average = 4.60s

Not bad for an ancient 4-bit CPU and the emulation of an ancient 4-bit CPU

One of the reasons for such performance is because I avoided dynamic/heap memory allocation, fragmentation and garbage collection at all costs. Dynamic memory allocation needs copying/moving and copying/moving kills speed and performance. I hate garbage collectors, they are totally unpredictable. And if you don't leave garbage than you don't have to collect it, do you? That's why SATURN BASIC works a lot like FORTH internally. Actually, at first I intended to develop SATURN FORTH but I decided not to do it because I concluded that a more high-level language would be much more appropriate for practical use. FORTH is a great language but a little cumbersome to work with various data types: floating point numbers, complex numbers, strings, arrays, matrices, etc. But a lot of code I developed for SATURN FORTH made it into SATURN BASIC.

SATURN BASIC has no connection to the so-called HP BASIC available in HP-49G and HP-49G+/50G which is not BASIC at all, just an awkward algebraic wrapper over UserRPL. Furthermore, the interpreter doesn't use RPL operating system except some SysRPL code during the initialization and machine language math routines - there is really no need to reinvent the wheel here.

SATURN BASIC is free for your private, non-commercial use only! Commercial use is strongly prohibited, you cannot use it to make money! It is not crippled or limited in any way. But I am not responsible for anything you do and I don't have any obligation to anyone. I put a lot of my own time, knowledge and energy into this project, so I think I've done more than enough.

*** Individuality, not conformity! ***

As with all my software, SATURN BASIC has that "HrastProgrammer's" way-of-working and look-and-feel which is not appealing to everyone because I developed it for myself in the first place. I didn't have to make it compatible with any particular existing BASIC, so I was free to design it as I wanted to. The feature set is fixed and I will not change anything in this regard, no matter how some features could look strange or quirky at first sight. I am sharing SATURN BASIC because such development tool/environment didn't exist before and it could possibly be helpful to someone else as well. But, if you don't like it - don't use it, simple as that.

OK, SATURN BASIC download is here:

32K version ... https://www.hrastprogrammer.com/hrastbas/hrast32k.zip

48K version ... https://www.hrastprogrammer.com/hrastbas/hrast48k.zip

The installation is very simple and is the same for all calculators. First, send the appropriate HRAST file (HRAST48, HRAST49 or HRAST50) containing the interpreter to the calculator and store it to a variable. Then send the appropriate RAMH file (RAMH48 for HP-48G/G+/GX and RAMH49 for HP-49G and HP-49G+/50G) to the calculator and store it to (another) variable. Put the number of BASIC kilobytes (BTW, no "kibibytes" and similar crap, please) needed and execute RAMH. This will create SATURN BASIC environment in form of an character string object of the required size (for example, 8 RAMH to create an 8K environment, minimum is 2K). Store this environment to the HRAM variable and start the interpreter by executing the variable where HRAST file has been stored. The interpreter will look for the HRAM variable in the current directory and (if it finds one and it was not already initialized) will initialize it and continue execution. If it doesn't find the HRAM variable an "Object Not in Port" error will be reported and the interpreter will abort execution.

Please, note that bugs are inevitable in such a complex piece of software, especially in such early state and under various "borderline" conditions, so watch for them and report them to me if you find any. I just hope I didn't make such a terrible mistakes like typing x=18.9 on Atari ST BASIC causing "function not yet done System error #%N, please restart" error ... So far, The interpreter has been tested on the following calculators: HP-48GX ROM version R, HP-49G ROM version 1.19-5, HP-49G+ ROM versions 1.23/2.15 and HP-50G ROM version 2.15. If you have problems running on other ROM versions report them to me as well and I will investigate. I reserve the right to mark a particular bug as "feature" or "by design" if I judge that something isn't really a bug or even if it is a bug but could somehow be useful. I also reserve the right to fix some bugs in 48K version only, due to the lack of space in 32K version.

In order to save space the interpreter is using an unsupported ROM font table entry on HP-48G/G+/GX. On HP-49G and HP-49G+/50G the system font table stored in RAM is used but I don't have any experience with alternate fonts on those calculators. So, in both cases there is a slight possibility that something can go wrong with different ROM versions or different calculator configurations. If something like this occurs then, please, report this to me.

The manual is here:

https://www.hrastprogrammer.com/hrastbas...-BASIC.pdf

It still leaves a few things to desire and I will update it when needed. This is a reference manual, not a book teaching BASIC language - the reader is expected to have a good programming knowledge in order to use SATURN BASIC and to understand the content of this manual. Please, report all errors to me so I can correct them. Also note that english is not my native language, so I will appreciate very much all corrections in regard to grammar, spelling, etc.

Enjoy