VIC Super Expander Memory Map
Chuan Chee
St. Catharines, Canada
A map of the significant machine language routines in the VIC Super Expander. You can translate these hexadecimal numbers into decimal, then SYS to them and watch the effects.
General Input/Output Routines
| A000-A001 | Vector: RESET ($A044) | |
| A022-A003 | Vector: NMI ($A077) | |
| A004-A008 | ROM identification (‘a0CBM’) | |
| A009-A010 | Table: function key numbers | |
| A011-A043 | Table: initial function key definitions | |
| A044-A076 | RESET routine | |
| A077-A08A | NMI routine | |
| A08B-A0BE | Parse KEY (get parameters and check syntax) | |
| A0BF-A131 | Display all function key definitions | |
| A110-A11C | Print'° + chr$(34)' and an optional ‘+’ | |
| A11D-A131 | Print ‘° + chr$(13)’ and an optional ‘+’ | |
| A132-A135 | Table: ASCII string for output (‘key’ backwards) | |
| A136-A13F | Table: ASCII string for output (‘° + chr$(13)’ backwards) | |
| A140-A149 | Table: ASCII string for output (‘° + chr$(34)’ backwards) | |
| A14A-A17A | Delete current function key string (key number in .X) | |
| A17B-A1B0 | Insert string into function key definition area | |
| A1B1-A1BE | Locate function key definition (key number in .X, return index in .Y) | |
| A1BF-A213 | Table: new BASIC keywords in ASCII form | |
| A214-A237 | Table: vectors corresponding to new BASIC tokens ($CC to $DD) | |
| A238-A2A1 | Initialize kernal vectors, I/O, RAM | |
| A2A2-A2C1 | Table: kernal vectors (L,H) | |
| A2C2-A2C7 | Warm start routine | |
| A2C8-A317 | Output a character to device 3 (char in .A) | |
| A318-A336 | End music mode | |
| A337-A365 | Interpret keyboard matrix input | |
| A366-A369 | Table: keyboard matrix code for function keys | |
| A36A-A371 | Table: conversion pattern for function keys | |
| A372-A394 | IRQ routine | |
| A395-A3A5 | Input a char from any device (device number in $99) | |
| A3A6-A3B3 | Output a char to any device (char in .A, device num in $9A) | |
| A3B4-A3F1 | Input each char from keyboard buffer | |
| A3B4- A3E7 | Handle ‘RUN’ key | |
| A3E8-A3F1 | Handle ‘RETURN’ key | |
| A3F2-A3FC | Input from device 0 | |
| A3FD-A406 | Print an error message in GRAPHIC 0 mode (error token in .A) | |
| A407-A4B9 | Lexically analyse BASIC source line (translate to tokens) | |
| A4BA-A503 | Print BASIC tokens in ASCII form | |
| A504-A529 | Start new BASIC statement | |
| A515- A523 | Handle new tokens ($CC to $D6) | |
| A52A-A58A | Get and evaluate an expression | |
| A558- A58A | Handle new function tokens ($D7 to $DD) | |
| A58B-A596 | Table: BASIC vectors for RAM | |
| A597-A5A4 | Change BASIC vectors during RESET |
Music Routines
| A5A5-A5D0 | Save current sound table (address of table in .X,.Y) | |
| A5D1-A601 | IRQ music driver | |
| A602-A625 | Table: conversion for note index to frequency | |
| A626-A6E5 | Interpret music mode characters (char in .A) | |
| A629-A643 | Execute ‘O’ command, default 3 | |
| A644-A65D | Execute ‘T’ command, default 0 | |
| A65E-A674 | Execute ‘S’ command, default 4 | |
| A675-A686 | Execute ‘V’ command, default 7 | |
| A687-A693 | Execute ‘R’ command | |
| A694-A69B | Execute ‘P’ command | |
| A69C-A6A7 | Execute ‘Q’ command | |
| A6A8- | Play new note (note index in .Y) | |
| A6AB-A6B3 | Save new sound table when previous note finishes | |
| A6B4-A6B9 | Common return routine | |
| A6BA-A6CD | Play notes ‘A’ to ‘G’ | |
| A6CE-A6DA | Execute ‘#’ command | |
| A6DB-A6E5 | Execute ‘$’ command | |
| A6E6-A6EC | Table: conversion for notes to note index | |
| A6ED-A6EF | Table: conversion for octave to base note index | |
| A6F0-A6F9 | Table: conversion for tempo to duration (jiffies) |
Parsing New Command Routines
| A6FA- | Look for and evaluate first 1 -byte and two 2-byte parameters |
| A6FD- | Look for and evaluate two 2-byte parameters |
| A700- | Look for and evaluate one 2-byte parameter |
| A714-A71B | Saveone 1-byte parameter (parameter in .A, index in .Y) |
| A71C- | Look for and evaluate two 1-byte parameters |
| A71F-A72B | Look for and evaluate one 1-byte parameter |
| A72C-A73F | Parse GRAPHIC (get parameters and check syntax) |
| A740-A762 | Parse CIRCLE |
| A763-A7A4 | Parse DRAW |
| A7A5-A7BC | Parse POINT |
| A7BD- | Parse COLOR |
| A7C8-A7CE | Go to execute commands after parsing |
| A7CF-A7D8 | Parse REGION |
| A7D9-A7DC | Parse SCNCLR |
| A7DD-A7E9 | Parse SOUND |
| A7EA-A809 | Parse CHAR |
| A80A-A810 | Parse PAINT |
| A811-A817 | Parse RPOT |
| A818-A81B | Parse RPEN |
| A81C-A81F | Parse RSND |
| A820-A823 | Parse RCOL |
| A824-A827 | Parse RGR |
| A828-A842 | Parse RDOT |
| A843-A846 | Parse RJOY |
| A847-A84E | Look for first 1 -byte parameter |
| A84F-A866 | Indirect jump to execute new commands (pointer to parameter save area in .X,.Y, command index in .A) |
| A867-A878 | Table: vector to execute new commands (H) |
| A879-A88A | Table: vector to execute new commands (L) |
Execute New Command Routines
| A88B-AA22 | Execute GRAPHIC | ||
| A8AB-A94E | Handle GRAPHIC 1,2,3 if previous was 0. | ||
| A8D4-A942 | Transfer BASIC program to above $2000 and execute CLR | ||
| A943-A94E | Make screen at $1E00 and character set at $1000 | ||
| A94F-A9AB | Handle GRAPHIC 4 | ||
| A967-A9AB | Transfer BASIC program down to old location and execute CLR | ||
| A9AC- A9B7 | Handle GRAPHIC 0 if previous was 1,2,3 | ||
| A9B8-AA22 | Set up proper GRAPHIC screen | ||
| AA23-AA28 | Execute RGR | ||
| AA29-AA6A | Execute COLOR | ||
| AA6B-AA84 | Execute REGION | ||
| AA85-AA8B | Execute RCOL | ||
| AA8C-AAE6 | Execute RDOT | ||
| AAE7-AAF1 | Execute POINT | ||
| AAF2-AB12 | Execute SCNCLR | ||
| AB13-AB22 | Execute DRAW (c TO x,y...) | ||
| AB23-AB34 | Execute DRAW (c,x,y TO x,y ...) | ||
| AB35-AB54 | Execute SOUND | ||
| AB55-AB69 | Execute RSND | ||
| AB6A-AB76 | Execute RPOT | ||
| AB77-AB7D | Execute RPEN | ||
| AB7E- | Plot a single point from parameter save area | ||
| AB86-ABE4 | Plot a single point from beginning scaled X,Y coordinates | ||
| ABE5- | Set up pointers to character and colour memory | ||
| ABFA-AC0A | Set up pointer to colour memory | ||
| AC0B- | Draw a line with a new starting coordinate | ||
| AC11-AC92 | Draw a line starting from previous coordinate (using a version of Bresenham's DDA algorithm) | ||
| AC93-AD12 | Execute CIRCLE (using principal of digital differential analyser (DDA)) | ||
| AD13- | Convert starting angle to radians | ||
| AD19-AD22 | Divide FAC# 1 by 16 | ||
| AD23- | Calculate new scaled X and Y coordinate on locus | ||
| AD39-AD6B | Calculate unit offset * scaled radius | ||
| AD6C-ADDE | Execute PAINT | ||
| ADDF- | Check for possible new lower bound pivot coordinate | ||
| ADE8-AE01 | Save pivot coordinate | ||
| AE02-AE0B | Check for possible new upper bound pivot coordinate | ||
| AE0C- | Check if able to PAINT a coordinate | ||
| AE0F-AE1E | Check if able to PAINT a coordinate (X, Y in .A, .Y) | ||
| AE1F-AE23 | Move beginning scaled X,Y coordinate to .A, .Y | ||
| AE24-AE3B | Check if coordinate has been already plotted on | ||
| AE3C-AE44 | Move beginning scaled X coordinate to the right | ||
| AE45-AE51 | Move beginning scaled X coordinate 2 to the left | ||
| AE52-AE56 | Flag ‘FORMULA TOO COMPLEX’ error message | ||
| AE57-AED9 | Execute CHAR | ||
| AEDA-AF13 | Execute RJOY | ||
| AF14-AF33 | Set up correct VIC chip screen registers | ||
| AF34- | Save number of coordinates and colour register | ||
| AF39-AF3E | Save colour register | ||
| AF3F-AF47 | Copy beginning from ending scaled X,Y coordinate | ||
| AF48-AF75 | Scale X and Ycoordinates | ||
| AF76-AFB0 | Scale X or Y coordinate to the range 0 to 159 (.X = .A*coordinate*2/256) (number of columns or rows in .A) | ||
| AFB1-AFBA | Table: vector to map Y coordinate to colour memory (L) | ||
| AFBB-AFCE | Table: vector to map X coordinate to character memory (L) | ||
| AFCF-AFE2 | Table: vector to map X coordinate to character memory (H) | ||
| AFE3-AFE5 | Table: bit set for colour memory | ||
| AFE6-AFE6 | (not used-contains $00) | ||
| AFE7-AFEE | Table: bit mask for highres mode | ||
| AFEF-AFF6 | Table: bit mask for multicolour mode | ||
| AFF7-AFFA | Table: bytes to plot in multicolour mode | ||
| AFFB-AFFE | Table: conversion factor for VIC chip screen registers | ||
| AFFF-AFFF | (not used-contains $AA) |
Note:
| (H): | high byte of a two-byte address |
| (L): | low byte of a two-byte address |
| Vector: | two-byte address used for indirection of execution |
| Pointer: | two-byte address for data |
| Index: | one-byte offset fora table |
General RAM Area
| 0024 | Number of coordinates |
| 0024 | Flag: colour register mode ($FF= multicolour, $00 = highres) |
| 0024-0025 | Pointer: New start of variables/start of BASIC memory |
| 0026 | Temp area for building VIC chip registers / for building character byte / for saving starl of BASIC (L) |
Current Coordinates
| 0062 | Ending scaled X coordinate (0 to 159) |
| 0063 | Beginning scaled X coordinate (0 to 159) |
| 0064 | Scaled X difference (absolule value) |
| 0065 | Ending scaled Y coordinate (0 to 159) |
| 0066 | Beginning scaled Y coordinate (0 to 159) |
| 0067 | Scaled Y difference (absolute value -1) |
For Scaling Coornidates
| 0069 | Multiplicand- 1 |
| 006A | 16-bit product |
| 006B-006C | 10-bit multiplier |
For DRAW
| 0069 | Scaled X unit direction - 1 |
| 006A | Scaled Y unit direction |
| 006B-006C | Number of scaled Y units left to plot before next scaled X unit (count up) |
| 006D-006E | Number of points left to plot (count up) |
For PAINT
| 0069 | Index: pivot coordinates save area |
For CHAR
| 0069 | Current row (0 to 19) |
| 006A | Current column (0 to 19) |
| 006B | Length of string |
| 006C-006D | Pointer: string location |
General RAM Area
| 009B | Index : begining of current function key definition |
| 009B-009C | Pointer: current char set address/byte in char set/position in screen memory/destination of byte of BASIC program to transfer |
| 009D | Index: end of function key definition area |
| 009E | Current function key number/length of current function key string |
| 009F | Length of current function key string (count down) |
| 009E-009F | Pointer: byte in colour memory |
| 00AC-00AD | Pointer: current byte (function key definition, tape, scrolling) |
| 00C3 | Flag: 0 = have transferred BASIC program to a new location |
| 00C3-00C4 | Pointer: kernal set up/current music table/parameter save area ($033C) |
| 00FB-00FC | Pointer: top of BASIC memory (usually same as $0284-$0285) |
For Key
| 028F-0290 | Vector: interpret keyboard input ($A337) |
| 02A1 | Number of bytes taken by Super Expander in high memory ($88) |
| 02A2 | Number of characters in function key definition |
| 02A3 | Index: current byte of function key string |
| 02A4 | Length of function key string (amount left to output) |
For Music
| 02A5 | Previous character in music mode |
| 02A6 | Music mode ($80 = on) |
| 02A7 | Screen echo ($50 = on, $00 = off) |
| 02A8 | Current voice (sound register - 1) |
| 02A9 | Current note index |
| 02AA | Current duration (jiffies) |
| 02AB | Current sound amplitude (volume * 2) |
| 02AC | Current octave (base note index) |
| 02AD | Voice 1 note index (+ $80) |
| 02AE | Voice 1 duration count down (jiffies) |
| 02AF | Voice 2 note index (+ $80) |
| 02B0 | Voice 2 duration count down (jiffies) |
| 02B1 | Voice 3 note index (+ $80) |
| 02B2 | Voice 3 duration count down (jiffies) |
| 02B3 | Voice 4 note index (+ $80) |
| 02B4 | Voice 4 duration count down (jiffies) |
| 02B5-02BF | (for expansion) |
For Execution Of New Commands
| 02C0-02C2 | Jump table: execute new commands (JMP $A84F) |
| 02C3 | Current VIC chip left margin register |
| 02C4 | Current VIC chip top margin register |
| 02C5 | Current VIC chip number of columns register |
| 02C6 | Current VIC chip number of rows register |
| 02C7 | Current row of cursor |
| 02C8 | Current GRAPHIC mode |
| 02C9 | (for expansion) |
| 02CA | Current colour register parameter (while plotting) |
| 02CB | Current screen colour |
| 02CC | Current border colour |
| 02CD | Current character colour |
| 02CE | Current auxiliary colour |
| 02CF | Index: parameter save area (while plotting) |
| 02D0 | Current character set address page |
| 02D1 | Usual character set address page ($80) |
| 02D2-02D3 | Pointer: old limit of BASIC memory |
| 02D4 | Old screen memory page |
| 02D5 | Last scaled X coordinate (0 to 159) |
| 02D6 | Last scaled Y coordinate (0 to 159) |
| 02D7 | Flag: $00 = DRAW c,x,y TO, $01 = DRAW c TO/current number of out of range coordinates ($00 = within range) |
| 02D8 | Old number of out of range coordinates ($00 = within range) |
| 02D9 | Index: parameter save area (while getting parameters) |
| 02DA-02FF | (for expansion) |
Operating System Vectors
| 0300-0301 | Vector: error message | ($A3FD) |
| 0302-0303 | Vector: BASIC warm start | ($C483) |
| 0304-0305 | Vector: lexically analyse BASIC source line | ($A407) |
| 0306-0307 | Vector: print BASIC token in ASCII form | ($A4BA) |
| 0308-0309 | Vector: start new BASIC statement | ($A504) |
| 030A-030B | Vector: get and evaluate an expression | ($A52A) |
| 0314-0315 | Vector: IRQ | ($A372) |
| 0316-0317 | Vector: BRK instruction | ($A2C2) |
| 0318-0319 | Vector: NMI | ($FEAD) |
| 031A-031B | Vector: BASIC OPEN statement | ($F40A) |
| 031C-031D | Vector: BASIC CLOSE statement | ($F34A) |
| 031E-031F | Vector: set input | ($F2C7) |
| 0320-0321 | Vector: set output | ($F309) |
| 0322-0323 | Vector: restore I/O | ($F3F3) |
| 0324-0325 | Vector: input a character | ($A395) |
| 0326-0327 | Vector: output a character | ($A3A6) |
| 0328-0329 | Vector: test STOP key | ($F770) |
| 032A-032B | Vector: BASIC GET statement | ($F1F5) |
| 032C-032D | Vector: abort I/O | ($F3EF) |
| 032E-032F | Vector: user BRK instruction | ($A2C2) |
| 0330-0331 | Vector: BASIC LOAD statement | ($F549) |
| 0332-0333 | Vector: BASIC SAVE statement | ($F685) |
| 0334-033B | (for expansion) |
Save Area
| 033C-03F8 | Save area: parameter passing/pivot coordinates (PAINT) |
For Circle
| 033C | Index: X or Y | |
| 0347-0348 | Old scaled X coordinate on locus | |
| 0349-034A | Old scaled Y coordinate on locus | |
| 034B-034C | New scaled X coordinate on locus | |
| 034D-034E | New scaled Y coordinate on locus | |
| 034F-0353 | Floating point unit offset X coordinate | |
| 0355-0359 | Floating point unit offset Y coordinate |