How Do I Print to Printer With Casio VX-4 C?

[toml_12953]

I have a Casio VX-4 and the interface box with a Casio printer. I can print to the printer from BASIC using LPRINT but in C, I have to use stdprn somehow. The C instructions in the only manual I have are mostly in Japanese and online translators aren't much help. There is no fopen in the VX-4 version of C so I can't open the printer for output. Here's what I've tried:

FILE *stdprn;
fprintf(stdprn,"%d",3.14159);

This doesn't work.

[blackjetrock]

I don't have a VX-4 but from a C point of view, %d prints and integer not a float so looks a bit suspicious, you'll maybe get junk, or maybe Casio have a different %d.
Also, stdprn should be defined in stdio.h so you have created a local variable that hides the real stdprn when you define stdprn in that code. try taking out the

FILE *stprn;

line and add in

#include <stdio.h>

if it's not already there.

[toml_12953]

(08-05-2022 03:21 AM)blackjetrock Wrote:  I don't have a VX-4 but from a C point of view, %d prints and integer not a float so looks a bit suspicious, you'll maybe get junk, or maybe Casio have a different %d.
Also, stdprn should be defined in stdio.h so you have created a local variable that hides the real stdprn when you define stdprn in that code. try taking out the

FILE *stprn;

line and add in

#include <stdio.h>

if it's not already there.

Thanks for the reply!

Casio C can't include headers like stdio.h. I did manage to print, however. Here's the program as it runs in Casio VX-4 C. It's an adaptation of the program found on page 5-5 of Learning to Program in C by Thomas Plum:

Code:

/* powdem - demonstrate power function
 */
main()
       {
       short i;
       double pw();
       extern FILE *stdprn;
       for (i = 0; i < 10; ++i)
            fprintf(stdprn, "2 to the power %d equals %.0f\n", i, pw(2., (double)i));
       exit();
       }
/* pw - return (positive) x to the power y
 */
double pw(x, y)
       double x;    /* base */
       double y;    /* exponent */
       {
       return (exp(log(x) * y));
       }

2 to the power 0 equals 1
2 to the power 1 equals 2
:
:
2 to the power 9 equals 512

Some changes I had to make:

1) Casio C needs to define functions that come after main() so I had to add

double pw();

in main()

2) User-defined functions can't duplicate predefined functions so I had to rename pow() to another name. I chose pw()

3) The statement

extern FILE *stdprn

had to be added to use a file pointer to the printer.

4) In Casio C, exit() can't take a parameter so the parameter in the book had to be removed.

[urbancamo]

Nice to see someone is still using one of these - I have one being shipped from Japan. The idea is to scan and then translate the documentation so we finally have an English manual for this very special Casio offering!

Regards, Mark.