RSSAVE

The first new function since the initial release has been finished — and goes into beta test soon. It is the RSSAVE function. It is quite an interesting and very powerful function. When I first used it on the original I was amazed what the RSSAVE and RSLOAD combo could do.

In the original calculator the RSSAVE would save the M-register and / or the programs over the RS232C interface. Most intriguing is that the programs where stored in plan ASCII text. All special characters where either replaced by standard characters or by descriptions in square brackets:

Alpha Character		Program Steps
×	[MUL]	×	*	σn	SDX	sin⁻¹	ASN
÷	[DIV]	÷	/	σn-₁	SDXN	cos⁻¹	ACS
E	[EXP]	10ˣ	10^X	x̅	MEANX	tan⁻¹	ATN
Σ	[SGM]	eˣ	e^X	XD	XD	sinh⁻¹	HYPASN
█	[BLK]	X²	X^2	XDEL	XDEL	cosh⁻¹	HYPACS
µ	[MIC]	√	SQR	R→P	R>P	tanh⁻¹	HYPATN
→	[RTA]	yˣ	X^Y	P→R	R>P	±	+/-
←	[LTA]	ʸ√x	X^(1/Y)	eng←	SENG	X↔Y	X<>Y
π	[PI ]	π	PI	°’”←	SDMS	x≥0	X>=0
AR__	[AR__]	X↔M__	X<>M__	°’”	DMS	x≥f	X>=F

In the simulator I replicated the function as follows:

• The M-register and / or the programs are stored in a plain text file using the same replacement characters. This is unlike PRT command which used exotic unicode characters to replicate / resemble the original calculator characters.
• Line length is 120 characters as it was in the original. For comparison: PRT uses 40 characters as line lengths.

This allows you load the saved program into a real calculator using an RS-232C interface. Which is one of the most amazing features of the FX-603P: It has a text parser to load plain text programs from the RS-232C interface.

Computers with RS-232C interface have become quite rare. But there are two options open:

1. If you have a working FA-6 interface then get a USB to RS-232C interface. They are quite cheap and powered by the USB and not bigger then just an RS-232C cable.
2. If you, like me, could not lay your hands on a real FA-6 then get a “USB interface for the Casio FX-850P/FX-880P and the PC”. It has the size of a large postage stamp, is USB powered, connects right to your FX-603P and Works with Windows, Mac OS X and probably Linux as well.

Here a video showing the process of transferring a program from the Simulator to a real calculator.

Of course it is not as easy as it looks. You need to know of the workings of the RS-232C interface, baut rates, data bits, stop bits. Both the terminal emulator and the calculator need to configured identically else the communication will fail. You find the needed POKE command on page 88 of the original Manual.