BASIC-16A

* NAME: BASIC-16A DOC 70181826000 REV A PAGE 14

0459 * RETURN STACK FORMAT 0460 * 0461 * 0462 * PURPOSE: TO HOLD RETURN INFORMATION FOR 0463 * GOSUB+RETURN SEQUENCES. 0464 * 0465 * TABLE SIZE: FIXED LENGTH, 16 WORDS 0466 * 0467 * ENTRY LENGTH: TWO WORDS 0468 * 0469 * ENTRY FORMAT: 0470 * 0471 * 0472 * ................................. ......... 0473 * : : . 0474 * : SI POINTER TO GOSUB STATEMENT : . 0475 * : : . 0476 * :...............................: . 0477 * : : . 0478 * : SBP TO STATEMENT FOLLOWING : . 0479 * : GOSUB, OR ZERO IF GOSUB IS : . . . 0480 * : LAST STATEMENT ON ITS LINE : . . . 0481 * : : ... 0482 * :...............................: . 0483 * 0484 * 0485 * POINTERS: 0486 * 0487 * RTB - POINTER TO THE FIRST WORD OF 0488 * THE FIRST AVAILABLE ENTRY, 0489 * NEVER IS ALTERED. 0490 * 0491 * RTM - POINTER TO THE LAST WORD OF 0492 * THE LAST AVAILABLE ENTRY, 0493 * NEVER IS ALTERED. 0494 * 0495 * RTR - POINTER TO THE FIRST WORD OF 0496 * THE NEXT FREE ENTRY. IF THE 0497 * TABLE IS EMRTY. RTP=RTB. IF 0498 * THE TABLE IS FULL, RTP=RTM+1. 0499 * 0500 * 0501 * 0502 EJCT