| I | Memory Map | page 1 |
| A Mega Drive 16-bit Mode | page 1 | |
| 1 68K Memory Map | page 1 | |
| 2 Z80 Memory Map | page 2 | |
| 3 68000 Access to Z80 Memory | page 2 | |
| 4 I/O Area | page 3 | |
| 5 Control Area | page 3 | |
| 6 VDP Area | page 4 | |
| II | VDP 315-5313 | page 5 |
| A Terminology | page 6 | |
| B Display Specification | page 6, 7 | |
| C VDP Structure | page 8 | |
| 1 CTRL | page 8 | |
| 2 VRAM | page 8 | |
| 3 CRAM | page 8 | |
| 4 VSRAM | page 8 | |
| 5 DMA | page 8 | |
| D Interrupt | page 9 | |
| 1 Vertical Interrupt (V-INT) | page 9 | |
| 2 Horizontal Interrupt (H-INT) | page 9 | |
| 3 External Interrupt (EX-INT) | page 10 | |
| E VDP Port | page 10 | |
| 1 $C00000 (Data Port) | page 10 | |
| 2 $C00004 (Control Port) | page 11 | |
| 3 $C00008 (HV Counter) | page 12 | |
| F VDP Register | page 13 | |
| 1 Mode Set Register No. 1 | page 13 | |
| 2 Mode Set Register No. 2 | page 13 | |
| 3 Pattern Name Table Base Address for Scroll A | page 13 | |
| 4 Pattern Name Table Base Address for Window | page 13 | |
| 5 Pattern Name Table Base Address for Scroll B | page 14 | |
| 6 Sprite Attribute Table Base Address | page 14 | |
| 7 Background Color | page 14 | |
| 8 H Interrupt Register | page 14 | |
| 9 Mode Set Register No. 3 | page 15 | |
| 10 Mode Set Register No. 4 | page 15 | |
| 11 H Scroll Data Table Base Address | page 16 | |
| 12 Auto Increment Table | page 16 | |
| 13 Scroll Size | page 16 | |
| 14 Window H Position | page 16 | |
| 15 Window V Position | page 17 | |
| 16 DMA Length Counter Low | page 17 | |
| 17 DMA Length Counter High | page 17 | |
| 18 DMA Source Address Low | page 17 | |
| 19 DMA Source Address Mid | page 17 | |
| 20 DMA Source Address High | page 17 | |
| G Access VDP RAM | page 18 | |
| 1 RAM Address Setting | page 18 | |
| 2 VRAM Access | page 19, 20, 21 | |
| 3 CRAM Access | page 22 | |
| 4 VSRAM Access | page 23 | |
| 5 Access Timing | page 24 | |
| 6 HV Counter | page 25 | |
| H Access DMA Transfer | page 26 | |
| 1 Memory To VRAM | page 26, 27 | |
| 2 VRAM Fill | page 28, 29, 30 | |
| 3 VRAN Copy | page 31, 32, 33 | |
| 4 DMA Transfer Capacity | page 34 | |
| I Scrolling Screen | page 35, 36 | |
| 1 Scrolling Screen Size | page 37, 38 | |
| 2 Horizontal Scrolling | page 39, 40 | |
| 3 Vertical Scrolling | page 41 | |
| 4 Scroll Patter Name | page 42, 43 | |
| 5 Pattern Generator | page 44, 45 | |
| J Window | page 46 | |
| 1 Display Position | page 46, 47 , 48, 49 | |
| 2 Window Priority | page 50 | |
| 3 Window Pattern Name | page 51 | |
| K Access Sprite | page 52 | |
| 1 Display Position | page 53, 54 | |
| 2 Sprite Attribute | page 55 | |
| 3 Sprite Size | page 56 | |
| 4 Sprite Display Capacity | page 57 | |
| 5 Priority Between Sprites | page 58, 59 | |
| 6 Sprite Pattern Generator | page 60 | |
| L Priority | page 61, 62, 63 , 64, 65, 66 | |
| M Color Palette | page 67, 68 | |
| N Interlace Mode | page 69, 70 | |
| III | Backward Compatibility Mode | page 71 |
| A Mark III (MS Japan) | page 71 | |
| B Master System | page 71 | |
| C RAM Board | page 71 | |
| IV | System I/O | page 72 |
| A Version Number | page 72 | |
| B I/O Port | page 72, 73, 74 , 75 | |
| C Memory Mode | page 76 | |
| D Z80 Control | page 76 | |
| 1 Z80 BusReq | page 76 | |
| 2 Z80 Reset | page 76 | |
| E Z80 Area | page 77, 78 | |
| V | VRAM Mapping | page 79, 80, 81 , 82, 83, 84 , 85, 86, 87 |
| I | Z80 Mapping | page 1 |
| A Z80 Map | page 1 | |
| B Interrupt | page 1 | |
| II | 68K Control of Z80 | page 2 |
| A Z80 Start-up | page 2 | |
| A Z80 Handshake | page 3 | |
| III | FM Sound Control | page 3 |
| A 68K Accesses the FM Sound Source | page 3 | |
| B Z80 Accesses the FM Sound Source | page 3 | |
| IV | PSG Control | page 3 |
| Overview | page 4 | |
| A Little Bit About Operators | page 5, 6 | |
| Register Overview | page 7 | |
| Envlope Specification | page 8, 9 | |
| Part 1 Memory Map | page 10, 11, 12 , 13, 14, 15, 16 , 17 | |
| Test Program | page 17 | |
| Programmable Sound Generator (PSG) | page 18, 19, 20 |
| I | Explanation of Terms | page 2, 3 |
| II | Hardware Specifications | page 4 |
| (1) Mega-CD | page 4 | |
| (2) Genesis | page 4 | |
| III | Internal Configuration | page 5 |
| (1) Configuration Diagram | page 5 | |
| (2-1) Genesis | page 5 | |
| (2-2) Mega-CD | page 6 | |
| (3) Using the 6 Megabit Buffer | page 7 | |
| (3-1) PRG-RAM (4M) | page 7 | |
| (3-2) Word RAM (2M) | page 7 | |
| (3-2-1) 2 M Mode | page 7 | |
| (3-2-2) 1 M/1 M Mode | page 8 | |
| IV | Detailed Description of Functions | page 9 |
| (1) Twin CPUs | page 9 | |
| (2) Graphical Numeric Processing Functions | page 10 | |
| (2-1) Coordinate Conversion Function | page 10 | |
| (2-1-1) Basic Principle | page 10 | |
| (2-1-2) Rotation | page 11 | |
| (2-1-3) Enlargement/Reduction | page 12 | |
| (2-1-4) 3-D Effect | page 12 | |
| (2-2) Full Graphics Function | page 12 | |
| (2-3) Important Points About Both Functions | page 13 | |
| (3) Audio Functions | page 14 | |
| (3-1) CD-DA | page 14 | |
| (3-2) 8-channel Stereo PCM Sound Source | page 14 , 15 | |
| (3-3) 8-times Oversampling Digital Filter | page 16 | |
| (3-4) Fade-In/Out | page 16 | |
| (4) Appendices | page 17 | |
| (4-1) Moving Picture Processing Capability | page 17 | |
| (4-2) Sound | page 17 , 18 | |
| (4-3) Access Time | page 19 | |
| (4-4) CD-G Compatibility | page 19 |
| Terms Used In This Manual | page 1, 2, 3 |
| Outline Of Mega-CD Hardware - page missing | page 4 |
| Mega-CD Construction | page 5 |
| Bus Contruction Of CD-ROM Interior | page 6, 7, 8 , 9, 10, 11 |
| Mega-CD Hardware Specifications | page 12 |
| 1 | Mapping | page 12 |
| 1-1 Mapping Mode | page 12. 13 | |
| 1-2 Sub-CPU Mapping | page 14, 15 | |
| 1-3 Main-CPU Mapping | page 16, 17, 18 | |
| 2 | Mega-CD Register Table | page 19, 20, 21 |
| 3 | Sub-CPU Registers | page 22 |
| 3-1 Initialization | page 22, 23, 24 , 25 | |
| 3-2 CDC | page 26, 27 | |
| 3-3 Communication | page 28, 29 | |
| 3-4 General Purpose Timer | page 30 | |
| 3-5 Interrupt | page 30 | |
| 3-6 CDD | page 31, 32, 33 | |
| 3-7 Color Numeric Operation | page 34 | |
| 3-8 Rotation Scaling | page 35, 36, 37 , 38, 39, 40, 41 , 42, 43, | |
| 44, 46, 47, 48, 49 , 50, 51, 52, 53 , 54 | ||
| 3-9 Sub-Code | page 55 | |
| 4 | Main-CPU Registers | page 56 |
| 4-1 Initialization | page 56, 57 | |
| 4-2 CDC | page 58, 59 | |
| 4-3 Communication | page 59, 60 | |
| Supplements | page 61, 62, 63 |
| 1 | Overview Of The Product | page 1 |
| 2 | Block Diagram | page 2, (horizontal) |
| 3 | Description Of Pins | page 3, 4, 5 |
| 4 | Description Of Functions | page 6 |
| 4-1 Address Map | page 6 | |
| 4-2 Control Register | page 7, 8 | |
| 4-3 Internal Memory | page 9, 10 | |
| 4-4 Channel On/Off Register | page 10 | |
| 4-5 Microcomputer Interface IC | page 11 | |
| 4-6 Wave Memory Interface IC | page 11 | |
| 4-7 Internal Register Read Cycle | page 12 | |
| 4-8 DCA (Digital Control Amplifier) | page 13 | |
| 4-9 Wave Data Format | page 14 | |
| 5 | DC Electrical Specifications | page 15 |
| 6 | AC Electrical Specifications | page 16, 17 |
| 7 | Timing Chart | page 18 |
| 7-1 Pseudo SRAM I/F | page 18 | |
| 7-2 Mask ROM I/F | page 18 | |
| 7-3 CPU I/F | page 19 | |
| 7-4 CPU Interface | page 20, 21 | |
| 7-5 Pseudo SRAM I/F | page 22 |
| 1 | Mapping | page 1, 2 |
| 2 | Main CPU Mapping | page 3, 4 |
| 3 | Sub-CPU Mapping | page 5, 6 |
| 4 | Mega-CD Register Table | page 7, 8 |
| 5 | Sub-CPU Registers | page 9, 10, 11 |
| 6 | CDC | page 12, 13 |
| 7 | Communication | page 14 |
| 8 | General Use Timer | page 15 |
| 9 | Interrupts | page 15 |
| 10 | CDD | page 16, 17 |
| 11 | Color Calculation | page 18 |
| 12 | Rotation Compression | page 19, 20, 21 , 22, 23, 24, 25 , 26, 27, 28, 29 , 30, 31 |
| 13 | Subcodes | page 32 |
| 14 | Main-CPU | page 33 |
| 15 | CDC | page 34 |
| 16 | Communication | page 35, 36 |
| 1 | Overview Of The Mega-CD Disc Format | page 1 |
| 2 | Physical Format | page 2 |
| 2-1 Partition and Configuration of Disc Areas | page 2 | |
| 2-2 Configuration of Tracks | page 2, 3, 4 | |
| 3 | Logical Format | page 5 |
| 3-1 Sector Structure | page 5 | |
| 3-2 System Area | page 6 | |
| 3-3 Booting System | page 7 | |
| 3-4 File System | page 8, 9, 10 , 11, 12, 13, 14 | |
| 3-5 User File Table | page 15 | |
| 3-6 Others | page 15 |
| Appendix 1 Glossary | page 16, 17 |
| Appendix 2 System ID | page 18, 19 |
| Appendix 3 Disc ID | page 20, 21 |
| Appendix 4 Area for defining Japanese codes | page 22 |
| 1 | CD System Control Process Summary | page 1 |
| 1-1 Hardware Summary | page 1 | |
| 1-2 Process Summary | page 2 | |
| 1-3 CD System Control Chart | page 3 | |
| 1-4 CD System Memory Map | page 4 | |
| 2 | BIOS Call Summary | page 5 |
| 2-1 BIOS Call Functions | page 5, 6 | |
| 2-2 BIOS Call List | page 7, 8 | |
| 2-3 BIOS Call Type Chart | page 9 | |
| 2-4 Drive Control System Process Chart | page 10 | |
| 3 | BIOS Call Reference | page 11 |
| 3-D Drive (Mechanism) | page 12 | |
| 3-M CD-DA (Music) | page 13, 14, 15 , 16, 17 | |
| 3-R CD-ROM (Data) | page 18, 19 | |
| 3-B CD-BIOS (Other Functions) | page 20, 21, 22 | |
| 3-F FADER (Fader) | page 23 | |
| 3-C CDC (Decoder) | page 24, 25 | |
| 3-S SCD (Subcode) | page 26, 27, 28 | |
| 3-L LED (LED Display) | page 29 | |
| 4 | System Bootstrap Sequence | page 30 |
| 4-1 CD Boot System Mode 1 (Boot from cartridge) | page 30 | |
| 4-2 CD Boot System Mode 2 (Boot from CD-DISC) | page 30 | |
| 4-3 Booting Application Programs | page 31, 32 | |
| 5 | Jump Table And User Calls | page 33 |
| 5-1 Structure of the Jump Table | page 33 | |
| 5-2 BIOS Call Sequence | page 33 | |
| 5-3 User Call Sequence | page 34 | |
| 5-4 Exception Processing Sequence | page 35 | |
| 6 | Boot System | page 36 |
| 6-1 CD-Boot | page 36, 37 | |
| 7 | Back-Up RAM | page 38 |
| 7-1 Back-up RAM | page 38, 39, 40, 41, 42, 43, 44, 45 |
| Genesis Tech Bulletin #0 | page 1 |
| Genesis Tech Bulletin #1 | page 1 |
| Genesis Tech Bulletin #2 | page 1 |
| Genesis Tech Bulletin #3 | page 1 |
| Genesis Tech Bulletin #4 | page 1, 2 |
| Genesis Tech Bulletin #5 | page 1, 2, 3 |
| Genesis Tech Bulletin #6 | page 1 |
| Genesis Tech Bulletin #11 | page 1 |
| Genesis Tech Bulletin #12 | page 1 |
| Genesis Tech Bulletin #13 | page 1 |
| Genesis Tech Bulletin #14 | page 1 |
| Genesis Tech Bulletin #27 | page 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 |
| Genesis Tech Bulletin #28 | page 1, 2 |
| Genesis Tech Bulletin #29 | page 1 |
| Genesis Tech Bulletin #29a | page 1 |
| Genesis Tech Bulletin #31 | page 1 |
| Genesis Tech Bulletin #32 | page 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, |
| Mega-CD Tech Bulletin #1 | page 1, 2, 3 , 4, 5 |
| Mega-CD Tech Bulletin #19 | page 1 |
| Mega-CD Tech Bulletin #20 | page 1, 2 |
| Mega-CD BIOS Tech Bulletin | page 1, 2 |
| Cinepak Tech Bulletin #01 | page 1 |
| Cinepak Tech Bulletin #02 | page 1 |
| Addendum 1 | page 1 |
| Addendum 3 | page 1, 2, 3 , 4, 5 |
| Addendum 4 | page 1 |
| Software Standards | page 1, 2, 3 , 4, 5, 6 , 7, 8, 9 |
| Manual Correction | page 1 |
| Software Guidelines | page 1, 2 |
| Technical Memo #4 | page 1, 2 |
| Misc FAX | page 1 |
