SuperBASIC Variables
The basic variables are used by SuperBASIC to hold details of how the Basic system looks. Some of these are helpful to user written programs, others are not.
SuperBasic Variables Area
| Offset | Size | Mnemonic | Description |
|---|---|---|---|
| $00 | Long | BV_BFBAS | Buffer Base |
| $04 | Long | BV_BFP | Buffer running pointer - aka Top |
| $08 | Long | BV_TKBAS | Token List |
| $0C | Long | BV_TKP | Token List Top |
| $10 | Long | BV_PFBAS | Program File Base |
| $14 | Long | BV_PFP | Program File Top |
| $18 | Long | BV_NTBAS | Name Table Base |
| $1C | Long | BV_NTP | Name Table Top |
| $20 | Long | BV_NLBAS | Name List Base |
| $24 | Long | BV_NLP | Name List Top |
| $28 | Long | BV_VVBAS | Variables Values Base |
| $2C | Long | BV_VVP | Variables Values Top |
| $30 | Long | BV_CHBAS | Channel Table Base |
| $34 | Long | BV_CHP | Channel Table Top |
| $38 | Long | BV_RTBAS | Return Table Base |
| $3C | Long | BV_RTP | Return Table Top |
| $40 | Long | BV_LNBAS | Line Number Table Base |
| $44 | Long | BV_LNP | Line Number Table Top |
| $48 | Long | BV_BTP | Backtrack Stack during parsing |
| $4C | Long | BV_BTBAS | Backtrack Stack Base |
| $50 | Long | BV_TGP | Temporary Graph Stack during Parsing |
| $54 | Long | BV_TGBAS | Temporary Graph Stack Base |
| $58 | Long | BV_RIP | Maths Stack Top |
| $5C | Long | BV_RIBAS | Maths Stack Base |
| $60 | Long | BV_SSP | System Stack Top |
| $64 | Long | BV_SSBAS | System Stack Base |
| $68 | Word | BV_LINUM | Current Line Number |
| $6A | Word | BV_LENGTH | Current Line Length |
| $6C | Byte | BV_STMNT | Current Statement on Line |
| $6D | Byte | BV_CONT | Continue ($80) or stop ($00) Processing |
| $6E | Byte | BV_INLIN | Processing in-line clause or not. Loop ($01), other ($FF) or off ($00) |
| $6F | Byte | BV_SING | Single line execution on ($ff) or off ($00) |
| $70 | Word | BV_INDEX | Name table row of last in-line loop index used |
| $72 | Long | BV_VVFREE | First free space in variables area |
| $76 | Long | BV_SSSAV | Value of SP to go to when Out of Memory occurs |
| $7A | 6 Bytes | Currently unused | |
| $80 | Long | BV_RAND | Randon number |
| $84 | Long | BV_COMCH | Command Channel ID |
| $88 | Word | BV_NXLIN | Line number to start after |
| $8A | Byte | BV_NXSTM | Statement to start after |
| $8B | Byte | BV_COMLN | Command line saved ($FF) or not ($00) |
| $8C | Word | BV_STOPN | Set stop number |
| $8E | Byte | BV_EDIT | Program has been edited ($FF) or not ($00) |
| $8F | Byte | BV_BRK | Break during I/O ($00) or not ($80) |
| $90 | Byte | BV_UNRVL | Need to unravel ($FF) or not ($00) |
| $91 | Byte | BV_CNSTM | Statement to CONTinue after |
| $92 | Word | BV_CNLNO | Line number to CONTinue after |
| $94 | Word | BV_DALNO | Current DATA line number |
| $96 | Byte | BV_DASTM | Current DATA stamement number |
| $97 | Byte | BV_DAITM | DATA item counter |
| $98 | Word | BV_CNIND | In-line loop index to CONTinue with |
| $9A | Byte | BV_CNINL | In-line loop flag for CONTinue |
| $9B | Byte | BV_LSANY | Whether checking LIST ($FF) or not ($00) |
| $9C | Word | BV_LSBEF | Invisible top line number |
| $9E | Word | BV_LSBAS | Bottom line number in window |
| $A0 | Word | BV_LSAFT | Invisible bottom line number |
| $A2 | Word | BV_LENLN | Length of window line |
| $A4 | Word | BV_MAXLN | Number of lines in window |
| $A6 | Word | BV_TOTLN | Number of window lines so far |
| $A8 | Word | Currently unused | |
| $AA | Byte | BV_AUTO | AUTO or EDIT is on ($FF) or off ($00) |
| $AB | Byte | BV_PRINT | Print from PRTOK ($FF) or not ($00) |
| $AC | Word | BV_EDLIN | Next editable line number |
| $AE | Word | BV_EDINC | AUTO incerment number |
| $B0 | Long | BV_TKPOS | Location of A4 in Token List when starting a PROCedure |
| $B4 | Long | BV_PTEMP | Temporary pointer for GO_PROC |
| $B8 | Byte | BV_UNDO | Undo return stack ($FF) or not ($00). Results in PROC/FN Cleared. |
| $B9 | Byte | BV_ARROW | Arrow down ($FF) or up ($01) or neither ($00) |
| $BA | Word | BV_LSFIL | Where to fill window to, when relisting |
| $BC | Word | BV_WRLNO | WHEN ERRor line number. QDOS 1.10 onwards |
| $BE | Byte | BV_WRSTM | WHEN ERRor statement number. QDOS 1.10 onwards |
| $BF | Byte | BV_WRINL | WHEN ERRor in-line ($FF) or not ($000). QDOS 1.10 onwards |
| $C0 | Word | BV_WHERR | Processing WHEN ERRor ($80) or not ($00). QDOS 1.10 onwards |
| $C2 | Long | BV_ERROR | Last error code. QDOS 1.10 onwards |
| $C6 | Word | BV_ERLIN | Last error line number. QDOS 1.10 onwards |
| $C8 | Word | BV_WVNUM | Number of watched (WHEN) variables. QDOS 1.10 onwards |
| $CA | Long | BV_WVBAS | Base of WHEN variable table. QDOS 1.10 onwards |
| $CF-$9F | 49 Bytes | Currently unused | |
| $100 | BV_END | End of Basic Variables |