| Fast facts on Sega Mega Drive
| Manufacturer: Sega
| Variants: Mega Drive 2, Genesis 3, Mega Jet, Nomad, AtGames, Mega Tech, Mega Play, System C, System 18, Amstrad Mega PC, Al-Alamiah AX-660, Al-Alamiah AX-990
| Add-ons: Mega-CD, 32X, Demo System DS-16, ERX 308P, ERX 318P, Master Mega Converter, MD 8bit Converter, Mega/Master Adaptor, Mega Modem, Power Base Converter, Pro MegaMaster, Sprobe, Super Magic Drive
| Main processor: 68000
| US (NY/LA)
| US (Nationwide)
|| £189.99 
The Sega Mega Drive (メガドライブ), called the Sega Genesis in North America and Super Gam*Boy (수퍼겜보이) (later Super Aladdin Boy (수퍼알라딘 보이) in South Korea, is a video game console developed by Sega in 1988. The Sega Mega Drive is Sega's third home console, following the SG-1000 (including SG-1000 II) and the Sega Master System (Mark III). It was codenamed the Sega Mark V during development and is part of what is now known as the fourth generation of video game consoles.
The Mega Drive is widely considered to be Sega's most successful video game console. It sold over 40 million consoles worldwide, according to Sega, including more than 20 million in the United States, over 9 million in Western Europe, 3.58 million in Japan, and 3 million in Brazil.
It also had a software library consisting of more than one thousand games released for the system in total. As well as competing with Nintendo's Famicom (NES) and later Super Famicom (SNES) for market control, Sega also found itself fighting against NEC's TurboGrafx-16 (PC Engine in Japan), SNK's Neo Geo, the Atari Jaguar and numerous home computers in one of the biggest "console wars" of all time.
The Mega Drive would be succeeded by the Sega Saturn (released in 1994), and then the Sega Dreamcast (released in 1998).
The Mega Drive was envisioned at the next technological step over other video game consoles available at the time. It is a "16-bit" machine, named after its use of a 16-bit CPU (in this case, the Motorola 68000), and was marketed as being superior to popular "8-bit" consoles dominating the market at the time, usually the Nintendo Entertainment System (NES) but sometimes its immediate predecessor, the Sega Master System. 16-bit CPUs had been gaining popularity since the mid-80s, were widely used in arcade machines, and were almost expected to be found in new home computers - it was therefore considered logical that the next "generation" of dedicated video game consoles should follow suit.
The Mega Drive builds on technology found in the Master System (and with adaptors, is fully backwards compatible), though as well as upping the technical specifications for more demanding gameplay, sound and graphics, makes a number of cruicial changes to the design of consoles which continue to this day. Firstly it added a third face button, , to the (now ergonomically designed) control pad. The Mega Drive outputs sound in stereo, and makes an attempt to region lock games through software. Also, when utilising the right cables, the Mega Drive is natively able to produce a clearer image than its rivals (on top of its already higher resolution 320x240 display).
All Mega Drives ultilise a top-loading design (as opposed to the cumbersome VCR-style cartridge loading of the Western NES), while having removable controllers (unlike the Famicom). It was designed from day one to allow hardware expansions, and its use of dark plastic means that the "yellowing" of older systems (from bromine-based flame retardants reacting with oxygen) is less of an issue.
- Main article: Mega Drive consoles.
The original Mega Drive measures 28 cm×21.2 cm×7 cm. The top of the unit is split into two components: a circular emboss with the cartridge slot and a tagline (which was omitted on later versions), and a control panel containing the power and reset buttons and the volume slider for the headphones jack. Audio output through the original model was mono through the A/V port, while the headphone jack was used for stereo sound. A third DE-9 port on the back of the unit provided additional peripheral support, though was removed from later revisions.
Asian, Japanese and South Korean models have a cartridge locking mechanism which prevents cartridges from being removed when the power is on (which is why "Eastern" cartridges, as well as the Sonic & Knuckles cartridge and various others, have a cut-out on their left sides). Later runs included the TradeMark Security System, missing in early builds causing small compatibility issues, despite the feature having been planned early on.
Mega Drive 2
1993 saw this cost-reduced redesign (known as the Mega Drive II in Europe, and not explicitly referred to as anything other than "Genesis" in North America), at 22 cm×21.2 cm×5.9 cm, being introduced internationally. One of the major revisions from the original model was the removal of the headphones jack in favor of stereo output through a redesigned 9-pin A/V port. American and European models used a momentary switch for power while non-western models used a left-right switch. Furthermore, the audio mixing circuitry was modified, resulting in noticeably different quality audio output — here is a page with audio samples, provided by little-scale.
A common myth is that the Mega Drive 2 lacks a Z80 — the truth is that it lacks a Zilog Z80. During the Mega Drive's lifetime, Sega received various off-the-shelf chips from different manufacturers, and sometimes would rebrand chips as their own or make them themselves, which is what happened here (and which is why each Mega Drive has a different manufacturer for its 68000). If the Z80 was missing, most games would have no sound (or not all sound). In later revisions, the Z80 was integrated into a custom ASIC which also incorporated the major chips of the system.
- Main article: Genesis 3.
The Genesis 3 was a small version manufactured by Majesco in 1998 for the American market, which they had been manufacturing for until then. It is much smaller than its predecessors and lacks all expansions and fixes memory controller bugs — both rendering some games unplayable and the Sega CD and 32X unusable.
Portables: Mega Jet and Nomad
- Main articles: Sega Mega Jet and Sega Nomad.
The Mega Jet and Nomad were portable Mega Drive systems released near the middle/end of the system's lifetime. The Mega Jet, released in 1994, was originally designed for use on JAL airliners but was later released for Japanese consumers. The Mega Jet is a semi-portable system; the system has a built-in controller but requires an external power supply and a TV. The Nomad was a full portable in its own right, having an integrated screen and sound capabilities, in addition to a battery pack.
Arcade hardware: Mega Tech, Mega Play, and the System C
- Main articles: Mega Tech, Mega Play, System C.
The Mega Drive hardware was adapted for arcade use several times over the course of its life. The Mega Tech and Mega Play allowed arcade operators to provide somewhat modified versions of popular Mega Drive games for arcade play — these systems use special cartridges containing games and players can choose from the games plugged into the system. The System C is a different board built from modified Mega Drive hardware, boasting improved color abilities and (in later revisions known collectively as the System C2) improved sample playback. The System C was primarily home to puzzle games — Columns and Puyo Puyo were released on this hardware.
Data East is also known to have licensed Mega Drive hardware for an arcade version of High Seas Havoc; not much is known about this board.
Mega-CD combos: JVC Wondermega/X'eye, Pioneer LaserActive, Sega Multi-Mega, and Aiwa Mega CD
- Main articles: Wondermega, LaserActive, Sega Multi-Mega, Aiwa Mega CD.
Combination Mega Drive/Mega-CD units were developed over the course of the Mega-CD's lifetime. The Wondermega and LaserActive are standalone consoles; the LaserActive also plays LaserDiscs. The Multi-Mega is a portable audio CD player that can play Mega Drive and Mega-CD games when plugged in to wall power and a TV. The Aiwa Mega CD is a Mega Drive/Mega-CD packed into Aiwa's consumer-level portable CD stereos.
Computer combinations: Sega Teradrive, Amstrad Mega PC, al-Alamiah units
- Main articles: Sega Teradrive, Amstrad Mega PC, Al-Alamiah AX-660, Al-Alamiah AX-990.
The Teradrive and Mega PC are combination Mega Drive/IBM-compatible PCs made for the Japanese and UK markets, respectively. The three Al-Alamiah computers are combination Mega Drive/MSX computers for the Arabic market.
Modern System-on-a-Chip compilations
A variety of companies now make licensed system-on-a-chip units in a variety of fashions that contain single-chip Mega Drive implementations and several licensed ROM images. TecToy-made SoaCs also contain several "new" MD games, however these are believed to be — and likely are — Java 2 Mobile Edition games running on additional hardware. For a full list of SoaCs, see the template at the bottom of the page.
The Mega Drive runs games housed in plastic cartridges uniquely shaped to fit the system. Though the technology exists to run Sega Master System games, the Power Base Converter is required to convert between the differing pin connections and slot sizes.
Official Mega Drive cartridges are generally smaller than their Master System/Mark III counterparts, with rounded edges and, in the case of "western" systems, bigger labels layered over the top and front of the cartridge. Region locking exists, albeit in a selection of rather crude forms - the TradeMark Security System, which is missing in many early Mega Drive systems, through software checks implemented manually by developers (which did not begin to feature in new releases until 1993), and differences in cartridge shape. Region locking is easily circumvented through the use of adapters - troubles only arise when dealing with 50Hz/60Hz differences between NTSC and PAL systems, leading some games to run too slowly while others, too fast.
As with the Master System, Sega-manufactured Japanese, Korean and Asian cartridges are shaped differently to those seen in North America, South America, Europe and Oceania, however the differences largely concern the aesthetics - "Eastern" Japanese-style cartridges opting for a more rounded approach with ridges, while "Western" cartridges being more angular and simplistic. Unlike the Master System, the Mega Drive has end-labels for easier reading and storage in western regions.
Pin layout is the same between the two types, however the base of the cartridge determines whether it can be safely inserted into the system - two extra pieces of plastic prevent Japanese cartridges from being inserted in western systems - these can be removed with modification, or as mentioned above, circumvented with adapters. This extra plastic is not present in systems such as the Genesis 3 and Sega 32X, nor does it exist in Japanese Mega Drives.
One interesting feature of Japanese cartridges is a inclusion of a cartridge "lock", which prevents the cartridge from being removed when the system turns on. A plastic piece from the system is slid across to a gap on the left hand side of a Japanese cartridge, securing it in place when the power switch is moved (similar tricks can be found on the Super NES and the TurboGrafx-16). This locking mechanism is only present in Japanese Model 1 Mega Drives and is absent in all western models - the vast majority of western cartridges lack the gap required for cartridge locking, with exceptions being the likes of "special" cartridges, e.g. Sonic & Knuckles.
The lack of cartridge lock can be exploited, for example, to gain access to the level selection screen in Sonic 3D Blast.
Official cartridge designs
Cartridge designs for Altered Beast - though labels would change dramatically over the console's run, the physical shape would remain consistent.
Alternative cartridge designs
Though Sega manufactured the bulk of Mega Drive cartridges, many were created externally by the likes of Electronic Arts, Accolade, Sunsoft and Codemasters.
- System master clock rate: 53.693175 MHz (NTSC), 53.203424 MHz (PAL) 
- Master clock cycles per frame: 896,040 (NTSC), 1,067,040 (PAL)
- Master clock cycles per scanline: 3420 
- Main CPU: Motorola 68000
- Clock rate: 7.6705 MHz (NTSC), 7.61 MHz (PAL)
- The 68000 has a 24‑bit address space, allowing access to up to 16 MB of memory. Sega's memory map for the Mega Drive allowed games to be up to 4 MB without the use of a memory mapper; games that tried to go up to 10 MB would find their memory maps crushed by the Sega CD (which took the second 4 MB block) and Sega 32X (which took 2 MB of the third 4 MB block). All devices are memory mapped.
- Games using save memory also needed to have the memory in the cartridge map; larger games, such as Phantasy Star IV, used a mapper to swap out cart space for SRAM during a save.
- Instruction set: 16‑bit and 32‑bit CISC instructions
- Bus width: 16‑bit 
- Sound CPU: Zilog Z80
- Clock rate: 3.58 MHz (NTSC), 3.55 MHz (PAL)
- Some games did not use the Z80, other games used it only for sample playback, but most used it for sound processing
- 8 KB program RAM which the 68000 and the Z80 can freely write to (though the 68000 must request the Z80 bus)
- Can access 32 KB of the 68000 memory map at once (while it should be used for accessing the cartridge, setting the bank register elsewhere can work on some hardware)
- Instruction set: 8‑bit and 16‑bit instructions
- Bus width: 8‑bit
- CPU instruction performance: 1.8614 MIPS (NTSC), 1.8466 MIPS (PAL) 
- 68000 performance: 1.3423 MIPS (NTSC), 1.3318 MIPS (PAL)
- Z80 performance: 0.5191 MIPS (NTSC), 0.5148 MIPS (PAL)
- FM sound chip: Yamaha YM2612, clocked at the 68000 clock speed (7.6705 MHz in NTSC, 7.61 MHz in PAL)
- 6 channels of FM synthesis, Operator Type‑N
- The third channel can enter a Special Mode, or multifrequency mode, where each individual operator has a different frequency
- The sixth channel can enter a DAC mode where the sound program constantly streams 8‑bit unsigned PCM data to mix directly into the output waveform
- 1 sine wave LFO (low frequency oscillator) channel
- Mapped to the Z80 address space — 68000 must request the Z80 bus to use
- Some Mega Drive 2 systems actually use the core from the chip's CMOS equivalent, the YM3438
- IRQ interrupt capabilities: IRQ2 sound interrupt 
- PSG sound chip: Sega PSG (SN76496), clocked at the Z80 clock speed (3.58 MHz in NTSC, 3.55 MHz in PAL) and built into the VDP — same as with the Master System
- Based on TI SN76489
- 4 audio channels: Three channels of pure square wave tones, and one noise channel
- The noise channel can play either white noise or "periodic noise" either at one of three preset frequencies or using the frequency of the third tone channel (consequently, that channel will be mute)
- Can be freely accessed by both the 68000 through the VDP and the Z80 through its memory map
- The cartridge connector has two pins which allow stereo sound mixing directly from cart. No game used this, however, but the 32X uses it for its PWM audio
- The Mega Drive 1 has mono audio output from the TV output and stereo output from a built‑in headphone jack, plus a built‑in volume control. Future models drop the headphone jack and do stereo output from the TV output
- GPU chipset:
- VDP: Sega 315‑5313 (Yamaha YM7101) 
- Based on Sega Master System VDP (in turn, based on TI TMS9918)
- All TMS9918 modes were removed and replaced with several new modes
- Controls background playfields and foreground sprites 
- Clock rate: 13.3 MHz
- Pixel clock rate: 6.711648 MHz 
- Bus width: 16‑bit
- Memory bus clock rate: 6.711648 MHz
- IRQ interrupt capabilities: IRQ6 VBlank interrupt, IRQ4 H‑Int (Horizontal Interrupt) scanline interrupt 
- DMA controller: Capable of DMA, high-speed fills and memory transfers, can transfer data from 68000 address space to VRAM/CRAM/VSRAM during active display and VBlank 
- RGB/Composite Video Encoder: Sony CXA1145 (NTSC/PAL) / Fujitsu MB3514 (PAL) 
- Colorburst clock frequency: 3.579545 MHz (NTSC), 4.433618 MHz (PAL) 
- Screen resolutions:
- Progressive scan resolutions:
- NTSC: 320×224, 256×224
- PAL: 320×224, 256×224, 320×240, 256×240
- Interlaced resolutions:
- NTSC: 320×448, 256×448
- PAL: 320×448, 256×448, 320×480, 256×480
- "Interlaced mode" doubles the height of all four; it was used by some games, such as Sonic 2 for two‑player mode.
- Progressive scan: 262 (NTSC), 312 (PAL) 
- Interlaced: 524 (NTSC), 624 (PAL)
- Refresh rate: 59.92274 Hz (NTSC), 50.31974 Hz (PAL)
- Frame rate: 59.92274 frames/sec (NTSC), 50.31974 frames/sec (PAL)
- Four graphics layers: two tile planes (just a grid of tiles), "window" tile plane (cannot be transparent), sprite plane
- Tilemap background planes: 2 parallax scrolling planes, with line and row scroll effects per plane (can scroll and overlap rows of tiles), vertical and horizontal line scrolling, column scrolling (2 tiles per column), horizontal and vertical tile flipping, 1800 tiles per frame 
- Background window plane, behind scrolling planes 
- Sprite plane: 80 sprites on screen, 20 sprites per scanline, 16 sprite sizes (8×8 to 32×32 pixels), 16 colors per sprite, integer sprite zooming  (up to 320x224), definable sprite priorities, 32 bytes per sprite, sprite flipping, virtual 512×512 sprite space 
- Note: Priorities can be defined between planes. 
- Colors on screen: 
- Standard: 64 colors
- Mid‑frame palette swap: 75 colors
- Shadow/Highlight mode: 183–192 colors
- Direct color (homebrew) mode: 512 colors (160×224 resolution)
- Color can be changed for each line 
- 16 colors (4‑bit) per pixel 
- Color palette: 
- Standard: 512 colors
- Shadow/Highlight mode: 1536 colors
- Shadow/Highlight mode: Hardware lighting, shadow generation (matching each character's shape), triples color palette and colors on screen, increases colors per tile
- Video RAM: 65.1875 KB (66,752 bytes)
- 64 KB internal VRAM — used to store graphics tiles, mappings for all layers, and horizontal scrolling
- 64 9‑bit words of internal CRAM — used to store the color palette
- 64 colors split into four 16‑color lines; each tile can be drawn with one of these four color lines
- The first color in each line is transparent and any color of the entire palette can be used as a "background color" (when no pixels are drawn at a location); consequently the Mega Drive can display 61 colors on screen at once (unless raster effects or the Shadow/Highlight modes are used, in which case this number increases depending on the extent used)
- Colors are 9‑bit RGB with 3 bits per color component, allowing for 512 colors
- Shadow/Highlight modes increase color gamut
- 80 bytes internal VSRAM — used for vertical scrolling (10‑bit words, up to 20 different vertical scroll values for each of the two scrolling playfields)
- VDP fillrate: 13.3 MPixels/s
- Pixels per frame: 221,952 (NTSC), 264,309 (PAL)
- Sprite fillrate: 320 sprite texels per scanline, 81,920 texels (80× 32×32 sprites) per frame, 4.908 MTexels/s (NTSC), 4.122 MTexels/s (PAL)
- VDP pixel bandwidth: 6.341934 MB/s (4‑bit per pixel)
- Pixel bandwidth per frame: 103.354 KB (NTSC), 123.078 KB (PAL)
- DMA transfer rate: 864.754 KB/s (NTSC), 1355.782 KB/s (PAL) 
- DMA transfer per frame: 14,777.5 bytes (NTSC), 27,590 bytes (PAL)
- Note: The term "Blast Processing" primarily referred to the fast DMA transfer rate.
- 3D polygons: Capable of rendering 3D polygons with stock hardware (without enhancement chips)
- Geometry transformation: Up to 10,000 vertices/sec, 500 vertices per frame
- Geometry performance: Up to 3,333 polygons/sec, 166 polygons per frame
- Rendering fillrate: 2–5 MPixels/s
- Rendering performance:
- Other features: Semi‑transparency, FIFO memory circuit design, read/write of one line buffer method for drawing 
- System RAM: 136 KB
- Main RAM: 64 KB (repeated over the upper 2 MB of address space)
- VRAM: 64 KB
- Audio RAM: 8 KB
- VDP internal RAM: 152 bytes 
- CRAM (Color RAM): 72 bytes (576 bits)
- VSRAM (Vertical Scrolling RAM): 80 bytes (640 bits)
- Cartridge memory: 512–5152 KB
- System memory buses: 
- 16‑bit system bus — 68000 & VDP <‑> Main RAM & Cartridge ROM/RAM
- 8‑bit system bus — Z80 & YM2612 <‑> Audio RAM
- 16‑bit video bus — VDP <‑> VRAM
- System RAM chips: 
- Cartridge ROM chips: 16‑bit 
- Most cartridges: MROM, 5 MHz, 200 ns cycles 
- Some cartridges: MROM/EPROM, 7.6705 MHz (NTSC) or 7.61 MHz (PAL), 130/131 ns cycles 
- Internal processor bandwidth:
- 68000 internal bus: 14.630317 MB/s (NTSC), 14.514923 MB/s (PAL)
- Z80 internal bus: 3.414154 MB/s (NTSC), 3.385543 MB/s (PAL)
- VDP internal CRAM/VSRAM: 12.801452 MB/s
- System RAM bandwidth: 25.73 MB/s
- Main RAM: 10.038675 MB/s
- VRAM: 12.801452 MB/s
- Audio RAM: 2.889922 MB/s
- Cartridge ROM bandwidth: 9.536743 MB/s (most cartridges), 14 MB/s (some cartridges)
Mega Drive Memory Map
|| ROM Cartridge
|| Expansion Port Area (used by the Sega CD)
|| Unallocated (used by the Sega 32X)
|| Z80 Memory
|| only various meaningful
|| System registers
|| only $A11100 and $A11200 meaningful
|| Z80 control (/BUSREQ and /RESET lines)
|| only several meaningful
|| Assorted registers
|| $1F; mirrored
|| $10000; mirrored
|| Work RAM (games usually only use the uppermost mirror, at $FF0000)
- Controller input: Two male DE‑9 controller ports; one female DE‑9 expansion port (early MD1s only)
- Controller ports support two modes: parallel and serial
- Parallel supports 7‑bit bidirectional, with the console setting the direction of each bit.
- Parallel also supports optional active‑low interrupts on the TH line. (mapped to 68000 IRQ 2)
- Serial mode supports up to 4800 bps. (used by the Mega Modem on port 3)
- Expansion port: Used for Sega CD.
- Provides access to /FDC ($A120xx) and /DISK to indicate Sega CD presence.
- Maps Sega CD PRG RAM to $000000 when no cartridge is present, $400000 otherwise.
Sega Virtua Processor
- See Sega Virtua Processor specifications.
The Sega Virtua Processor (SVP) enhancement chip used in the Virtua Racing (1994) cartridge adds the following specifications:
- GPU: Samsung SSP1601 DSP @ 23 MHz (25 MIPS)
- 3D polygon graphics: 9000 polygons/sec
- Audio: 2 PWM channels
- RAM: 131 KB (2 KB instruction cache, 1 KB SRAM cache, 128 KB FPM DRAM)
- See Sega Mega-CD technical specifications.
The Sega CD (Mega CD) add‑on, released in 1991, adds the following specifications:
- CPU: Motorola 68000 @ 12.5 MHz (2.19 MIPS)
- GPU: Sega ASIC coprocessor
- Sound chip: Ricoh RF5c164
- Graphics: Sprite/tilemap scaling and rotation
- Colors on screen: 128 colors (HAM), 256 colors (FMV)
- 3D polygon graphics: 960 polygons/sec
- Sound: 8 PCM channels (16‑bit, 32 kHz), 1 streaming CD‑DA channel (16‑bit, 44.1 kHz)
- RAM: 848 KB (768 KB main, 64 KB audio, 16 KB cache)
- See Sega 32X technical specifications.
The Sega 32X add‑on, released in 1994, adds the following specifications:
- CPU: 2× Hitachi SH-2 (32‑bit RISC) @ 23 MHz (59.8 MIPS)
- Sound chip: 32X: Q‑Sound
- Sound: 10‑bit PWM, surround sound
- Graphics: 32,768 colors on screen
- 3D polygon graphics: 50,000 polygons/sec
- RAM: 256 KB main RAM, 256 KB VRAM
- Main article: History of the Sega Mega Drive.
- Main article: List of Mega Drive games.
- Main article: Sega Mega Drive/Magazine articles.
Print advert in GamePro
(US) #3: "September/October 1989" (1989-xx-xx)also published in:
- GamePro (US) #4: "November 1989" (1989-xx-xx)
- GamePro (US) #5: "December 1989" (1989-xx-xx)
Print advert in Game Players
(US) Vol. 1 No. 5 "November 1989" (1989-xx-xx)also published in:
- Game Players (US) Vol. 1 No. 6 "December 1989" (1989-xx-xx)
Print advert in Sega Power
(UK) #13: "December 1990" (1990-xx-xx)
Print advert in Sega Power
(UK) #14: "January 1991" (199x-xx-xx)also published in:
- Raze (UK) #3: "January 1991" (1990-11-29)
- Raze (UK) #4: "February 1991" (1991-12-20)
- Raze (UK) #5: "March 1991" (1991-01-31)
Print advert in Computer & Video Games
(UK) #113: "April 1991" (1991-03-16)also published in:
- Computer & Video Games (UK) #114: "May 1991" (1991-04-14)
Print advert in Player One
(FR) #1: "Septembre 1990" (1990-xx-xx)also published in:
- Joystick (FR) #9: "Octobre 1990" (1990-xx-xx)
Print advert in Joystick
(FR) #27: "Mai 1992" (1992-xx-xx)also published in:
- Joystick (FR) #29: "Juillet/Août 1992" (1992-xx-xx)
Print advert in Hobby Consolas (ES) #2: "Noviembre 1991" (1991-xx-xx)
Print advert in K
(IT) #22: "Novembre 1990" (1990-xx-xx)also published in:
- K (IT) #23: "Dicembre 1990" (1990-xx-xx)
Print advert in K
(IT) #24: "Gennaio 1991" (xxxx-xx-xx)also published in:
- K (IT) #25: "Febbraio 1991" (xxxx-xx-xx)
- K (IT) #26: "Marzo 1991" (1991-xx-xx)
Print advert in K (IT) #27: "Aprile 1991" (1991-xx-xx)
Print advert in Mega Force
(PT) #1: "Junho 1993" (1993-xx-xx)
Print advert in Mega Force
(PT) #1: "Junho 1993" (1993-xx-xx)
Print advert in Mega Force
(PT) #3: "Agosto 1993" (1993-xx-xx)also published in:
- Bestial! (PT) #3: "xxxx xxxx" (xxxx-xx-xx)
Toys 'R' Us print advert in Sega Visions
(US) #1: "June/July 1990" (1990-xx-xx)
Kay-Bee print advert in Sega Visions
(US) #1: "June/July 1990" (1990-xx-xx)
Sears print advert in Sega Visions
(US) #9: "August/September 1992" (1992-xx-xx)also published in:
- Sega Visions (US) #10: "November/December 1992" (1992-xx-xx)
- Electronic Gaming Monthly (US) 1993 Video Game Buyer's Guide (199x-xx-xx)
- Sega Visions (US) #11: "February/March 1993" (199x-xx-xx)
US ("we bring the arcade experience home")
US ("Genesis does sports")
- ↑ File:CVG UK 106.pdf, page 13
- ↑ File:MegaDrive UK PrintAd 1990-10.jpg
- ↑ 3.0 3.1 File:K IT 22.pdf, page 21
- ↑ 4.0 4.1 4.2 4.3 File:Sega Service Manual - Genesis II - Mega Drive II (PAL) - 001 - June 1993.pdf
- ↑ https://github.com/ekeeke/Genesis-Plus-GX/blob/master/core/system.h
- ↑ http://www.digitpress.com/faq/megadrive.htm
- ↑ Obsolete Microprocessors
- ↑ FM-Drive User Manual
- ↑ 9.0 9.1 9.2 9.3 File:GenesisTechnicalOverview.pdf
- ↑ 10.0 10.1 Genesis (MESS)
- ↑ SN76496 (MAME)
- ↑ 12.0 12.1 12.2 Mega Drive PCB revisions
- ↑ 13.0 13.1 13.2 File:GenesisTechnicalOverview.pdf, page 2
- ↑ https://pineight.com/mw/index.php?title=Dot_clock_rates
- ↑ 15.0 15.1 File:GenesisTechnicalOverview.pdf, page 3
- ↑ File:CXA1145P datasheet.pdf
- ↑ File:MB3514 datasheet.pdf
- ↑ 315-5313 Information
- ↑ File:GenesisTechnicalOverview.pdf, page 14
- ↑ 20.0 20.1 Sega Genesis Comparison
- ↑ 21.0 21.1 21.2 21.3 21.4 21.5 How Sega Built the Genesis: Masami Ishikawa Inteview
- ↑ Sega Programming FAQ (October 18, 1995)
- ↑ Sega Master System VDP Documentation
- ↑ 24.0 24.1 Sega Genesis VDP Documentation
- ↑ 25.0 25.1 25.2 25.3 Sega Genesis VDP Documentation
- ↑ File:GenesisTechnicalOverview.pdf, page 45
- ↑ http://emu-docs.org/Genesis/ssf2.txt
- ↑ https://web.archive.org/web/20090204190244/consolasparasiempre.net/doc/MDPinRom.txt
- ↑ 29.0 29.1 Second Dimension R&T DxS-GEN24STH-01
- ↑ File:HM65256B datasheet.pdf
- ↑ File:TC51832 datasheet.pdf
- ↑ File:HM53461 datasheet.pdf
- ↑ File:KM424C64 datasheet.pdf
- ↑ File:MB81461 datasheet.pdf
- ↑ File:TMM2063P datasheet.pdf
- ↑ File:UPD4168 datasheet.pdf
- ↑ File:KM6264B datasheet.pdf
- ↑ File:LC3664R datasheet.pdf
- ↑ ROM Part Numbers
- ↑ File:MB834200A datasheet.pdf
- ↑ 41.0 41.1 File:MB838200B datasheet.pdf
- ↑ File:M27C322 datasheet.pdf
- ↑ File:GamePro US 004.pdf, page 52
- ↑ File:GamePro US 005.pdf, page 22
- ↑ File:GamePlayers US 0106.pdf, page 26
- ↑ File:Raze UK 03.pdf, page 64
- ↑ File:Raze UK 04.pdf, page 12
- ↑ File:Raze UK 05.pdf, page 12
- ↑ File:CVG UK 114.pdf, page 67
- ↑ File:Joystick FR 009.pdf, page 86-87
- ↑ File:Joystick FR 029.pdf, page 179
- ↑ File:K IT 23.pdf, page 2
- ↑ File:K IT 25.pdf, page 15
- ↑ File:K IT 26.pdf, page 64
- ↑ File:Bestial PT 03.pdf, page 32-33
- ↑ File:SegaVisions US 10.pdf, page 5
- ↑ File:EGM US BuyersGuide 1993.pdf, page 51
- ↑ File:SegaVisions US 11.pdf, page 7