MPLAB-C works the same way.  For example if you want to store a long and
work with the high and low bytes individually you would do this (because
MPLAB-C has math trouble with longs):

unsigned long a;
unsigned char al @ a;        // low byte
unsigned char ah @ a+1;   // high byte

These RAM locations are *NOT* reserved.

To reserve memory find the line in the PICName.h file (or similar):
#pragma memory RAM [MAXB0  - 0x26]  @ 0x26;     // first 0x25 locations reserved

and change it to:
#pragma memory RAM [MAXB0  - 0x28]  @ 0x28;      // reserve two additional bytes

Then

unsigned long a @ 0x26;
unsigned char al @ a;        // low byte
unsigned char ah @ a+1;   // high byte

a, al, ah will not be used by the compiler to assign any other variables.

rich


At 05:00 PM 4/14/98 -0700, you wrote:
>On Tue, 14 Apr 1998, John Bellini wrote:
>
>> How do you redefine the following from Byte Craft C compiler to HITECH?
>> The HITECH C compiler keeps giving me a "constant expression required"
>> error.
>>
>> char val[10] @ string[32];      // note this resides within string[]
>> char val2[7] @ string[42];      // saved string for 2 variable displays
>
>I would imagine you could do this using proper C with the Hi-Tech
>compiler by using a union.  The Hi-Tech compiler uses "@" to locate
>variables at specific hardware addresses; that's why you're getting the
>"constant expected" error -- it's looking for a physical memory address.
>
>> It also does not like this sort of definition.
>> bits special;                   // special handling, bank max.
>> bits system_flags1;             // system flags
>> bits system_flags2;             // system flags
>
>Look at Hi-Tech's "bit" type.
>
>> I looked at the help section but there is not much about what you can
>> and cannot do in regards to C syntax.
>
>All of the above is documented in the manual that's on the CD in the
>"Features and Runtime Environment" section.
>
>--
>John W. Temples, III       ||       Providing the first public access
Internet
>Gulfnet Kuwait             ||            site in the Arabian Gulf region
>