Thanks for "Mats".
I want to write a statistics program in 6502 assembly language.
So, I need floating-point routines.
I have already get a FADD/FSUB/FMUL/FDIV.

But, I meet a serious problem:How to convert an internal floating-point number to a printable string? How to get a floating-point number ...

How to convert an APPLE's floating-point number to a printable ASCII?

1)Howto convert ascii to "float"
2)Howto convert "float" to ascii
The Float-point number is stored in APPLE's format which is discussed in "I can't understand FLOATING POINT REPRESENTATION"

Thanks for dclxvi's explanation.
I just found The subtraction performed by FSUB is actually FP1 = FP2 - FP1. this evening.
And as you said, there are a lot of errors in the documentation, in fact.

As I had said at the beginning, I want to write a program in 6502 assembler language. This program ...

Yes, I have already read this
http://www.6502.org/source/floats/wozfp1.txt
http://www.6502.org/source/floats/wozfp2.txt
http://www.6502.org/source/floats/wozfp3.txt
Therefor I have the question about "APPLE's floationg-point number representation".
In "http://www.6502.org/source/floats/wozfp1.txt ...

I found an APPLE emulator at http://www.tomcharlesworth.pwp.blueyonder.co.uk/
Maybe it can help "Mats" print floating-point numbers.
Can "Mats" tell me how to print floating-point numbers with APPLE's BASIC?

I found some information of APPLE II's floating-point number representation at http://aplawrence.com/cgi-bin/wiki?FloatingPoint

["Tandy stored floating point nubers in what they called "XS128 notation" (Excess 128 is what they really meant) and MBASIC used packed BCD."
Tandy used excess 128 ...

1. Mantissa

The floating point mantissa is stored in two's complement representation
with the sign at the most significant bit (MSB) position of the high-order
mantissa byte. The mantissa provides 24 bits of precision, including sign,
and can represent 24-bit integers precisely. Extending ...

I can't understand FLOATING POINT REPRESENTATION of APPLE II in"Apple II Reference Manual (Red Book), January 1978, pages 94-95."

The Red Book said:
HIGH-ORDER MANTISSA BYTE
01.XXXXXX Positive mantissa.
10.XXXXXX Negative mantissa.
00.XXXXXX Unnormalized mantissa.
11.XXXXXX Exponent = -128 ...

I want some source code to complete a statistics program.Can anybody give me a source code? Or some detaile reference.
I have already writed a floating point add/sub/mul/div sub-procedure. They can process single precision floating point numbers.

Thanks.

But I'm a beginner,can anybody give me a source code?

I don't know how to calculate the square root of a floating point number,Can you help me?

The floating point number is reptrsented as this:
FLOATING POINT REPRESENTATION
1byte Exponent and 3bytes Signed Mantissa.

Thank you very much.