Difference between revisions of "83Plus:BCALLs:42F1"

Revision as of 16:58, 11 April 2007

Synopsis

Official Name: ChkFindSym

BCALL Address: 42F1

Recalls various pointers and information for a symbol in the VAT.

Inputs

• OP1 = Name of variable (with proper initial defining byte, see example)

Outputs

• HL = VAT pointer
• DE = Data location (to the best of my knowledge, please confirm this)
• B = Flash Page, or 0 if in RAM
• C = Length of Varibale Name
• A = 'unknown'
• carry flag is set if the variable is not found in the VAT

Registers Destroyed

'All'

Example

ld hl,varname
B_CALL Mov9toOp1
B_CALL ChkFindSym
jr c,notfound      ;carry flag is set if the VAT entry is not found
ex de,hl           ;put data pointer into hl 
xor a 
cp  b              ;see if b is 0, and the program is in the ram
jr z,unarchived      ;if so, jump to unarchived 

;do something to get it into RAM

unarchived:

;do something once it is in RAM

varName:
.db AppVarObj, "APPVAR",0