{{htmlmetatags>metatag-description:(ICL George 3 and George 4 GIN macro: BLOCK)}}
====== BLOCK ======
(GIN Macro)

**Defined in:** [[george:source:IFMACS|IFMACS]]

**Used in:** [[george:source:COPYFILA867|COPYFILA867]], [[george:source:EXOPEN867|EXOPEN867]], [[george:source:INSERT6|INSERT6]], [[george:source:INSERTBL6|INSERTBL6]], [[george:source:INSERTFR6|INSERTFR6]], [[george:source:INSERTHR6|INSERTHR6]], [[george:source:INSERTWO6|INSERTWO6]], [[george:source:MESSAD|MESSAD]], [[george:source:MESSAJ|MESSAJ]], [[george:source:MESSBC|MESSBC]], [[george:source:MESSBG|MESSBG]], [[george:source:MESSBI|MESSBI]], [[george:source:MESSCB|MESSCB]], [[george:source:MESSCF|MESSCF]], [[george:source:MESSCG|MESSCG]], [[george:source:MESSDA|MESSDA]], [[george:source:MESSDJ|MESSDJ]], [[george:source:MESSF|MESSF]], [[george:source:MESSG|MESSG]], [[george:source:PMCHAINS864|PMCHAINS864]], [[george:source:PMDUMPDA85|PMDUMPDA85]], [[george:source:PMFILE860|PMFILE860]], [[george:source:PMFS85|PMFS85]], [[george:source:PMSUMA867|PMSUMA867]], [[george:source:RESTERR864|RESTERR864]], [[george:source:WRITEFIP867|WRITEFIP867]], [[george:source:WTSTAT867|WTSTAT867]]

<code - BLOCK.mac.txt>
 HD5B ...[   
 HDK2 ...[   
 HF4L ...[ 'BLOCK' GROUP OF MACROS   
 HFJ= ...[ =======================   
 HG3W ...[   
 HGHG ...[   
 HH36 ...[   
 HHGQ ...[   
 HJ2B ...[   
 HJG2 ...[ A BLOCK IS IN THIS CONTEXT EFFECTIVELY A SUBROUTINE   
 HJ^L ...[ FOR WHICH ONLY ONE CALL IS ALLOWED (SINCE THERE IS
 HKF= ...[ NO LINK)  
 HKYW ...[   
 HLDG ...[ IT IS A BLOCK OF CODE STARTED BY 'BLOCK' AND TERMINATED   
 HLY6 ...[ BY 'ENDBLOCK'. THE EQUIVALENT OF CALL IS 'EXECUTE',   
 HMCQ ...[ OF WHICH ONLY ONE IS ALLOWED FOR EACH BLOCK.  
 HMXB ...[   
 HNC2 ...[ THE EFFECT OF AN EXECUTE IS TO BRN TO THE TOP OF THE  
 HNWL ...[ BLOCK. AT THE END OF THE BLOCK, A BRN IS DONE TO THE  
 HPB= ...[ INSTRUCTION FOLLOWING THE EXECUTE. THUS WE HAVE MERELY
 HPTW ...[ DISPLACED A BLOCK OF CODE FROM THE MAIN PATH AT THE   
 HQ*G ...[ COST OF TWO INSTRUCTIONS. THE GAIN IN READABILITY OF  
 HQT6 ...[ THE CODE MUST BE BALANCED AGAINST THIS OVERHEAD   
 HR#Q ...[   
 HRSB ...[   
 HS#2 ...[   
 HSRL ...[??? BLOCK SECT COMM FGN 1 DOC  
 HT?= ...[   
 HTQW ...#MAC  BLOCK 
 HW=G ...[     ===== 
 HWQ6 ...[   
 HX9Q ...[ MERELY A LABEL. ONLY MACROISED FOR READABILITY
 HXPB ...[   
 HY92 ...#DEF  %A0=0?+37?
 HYNL ...#NOR
</code>