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

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m (carry, not 'cary')
 
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=== Outputs ===
 
=== Outputs ===
 +
* [[83Plus:RAM:8478|OP1]] = Name of variable
 
* HL = VAT pointer
 
* HL = VAT pointer
* DE = Data location (to the best of my knowledge, please confirm this)
+
* DE = Data location (if in archive, will be address when page is put into [[83Plus:Ports:06|bank A]])
 
* B = Flash Page, or 0 if in RAM
 
* B = Flash Page, or 0 if in RAM
* C = Length of Varibale Name
+
* C = Length of Variable Name
* A = 'unknown'
+
* A = the lower 5 bits is the type. Use the mask 1Fh.
 
* carry flag is set if the variable is not found in the VAT
 
* carry flag is set if the variable is not found in the VAT
  

Latest revision as of 22:57, 16 January 2013

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

  • OP1 = Name of variable
  • HL = VAT pointer
  • DE = Data location (if in archive, will be address when page is put into bank A)
  • B = Flash Page, or 0 if in RAM
  • C = Length of Variable Name
  • A = the lower 5 bits is the type. Use the mask 1Fh.
  • 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