This Forum is Dedicated For all The Object Oriented PIC Lovers .......... The concept behind OOPic is straight forward. Use preprogrammed multitasking Objects from a library of highly optimized Objects to do all the work of interacting with the hardware. Then write small scripts in Basic, C, or Java syntax styles to control the Objects. During operation, the Objects run continuously and simultaneously in the background while the scripts run in the foreground telling the objects what to do.

Monday, March 10, 2008

Re: [oopic] more debugging

At 01:26 PM 3/9/2008, Brian Lloyd wrote:
>I am aware of the differences between signed and unsigned types. (I
>must admit to being surprised to see that type char is signed. That
>makes no sense to me.)

char defaulting to signed is classic / standard behaviour for real C
compilers. It dates from the early days when memory space was tight
and using 8 bit variables was common. You can't calculate a negative
difference with unsigned values, which is why programmers normally
use signed variables (hello Year 2038 problem!)

When working with real compilers, I always define my own unsigned 8
bit datatype:

typedef unsigned char BYTE; // portable unsigned 8 bit data type


It seems correct to me for "byte", "word", "dword", etc. datatypes to
be unsigned. I tend to equate them with memory addresses, block
sizes, and so on - things that can never be negative.

char, int, long - these are the signed counterparts. It works for me.


...Andy



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