Barrel Power Supplies

Power Adapter Information

Table

Power Adapter Barrel Connector Compatibility Table

System	Voltage	Current	Barrel Size	Polarity	Official PSU Model
Group 1 – 9V DC, 5.5mm × 2.1mm, Centre Negative
ZX Spectrum +2 / +2A / +3	9V DC	2.1A	5.5 × 2.1mm		Sinclair PSU (various OEM)
NEC PC Engine Duo / TurboDuo	9V DC	1.5A	5.5 × 2.1mm		DUO-AC
Sega Saturn	9V DC	1.5A	5.5 × 2.1mm		MK-2103
Super Nintendo (PAL)	9V DC	1.3A	5.5 × 2.1mm		SNSP-002E(FRG)
Nintendo NES (PAL)	9V DC	1.3A	5.5 × 2.1mm		NES-002E
Atari Jaguar / Jaguar CD	9V DC	1.2A	5.5 × 2.1mm		PA-1400 / MK-4120
Sega CD (Model 1 & 2)	9V DC	1.2A	5.5 × 2.1mm		MK-1602
Sega Master System	9V DC	1.2A	5.5 × 2.1mm		MK-3025
Sega Mega Drive / Genesis (Model 1)	9V DC	1.2A	5.5 × 2.1mm		MK-1602-05
NEC PC Engine / CoreGrafx / TurboGrafx-16	9V DC	0.85A	5.5 × 2.1mm		HES-ACA-01 / Turbo AC Adapter
Group 2 – 9V DC, 3.5mm × 1.35mm, Centre Negative
ZX Spectrum (16/48K)	9V DC	1.4A	3.5 × 1.35mm		Sinclair PSU
Atari 7800	9V DC	1.0A	3.5 × 1.35mm		C018187
Atari 2600 (VCS)	9V DC	0.5A	3.5 × 1.35mm		C017945
Group 3 – 9V DC, 4.75mm × 1.7mm, Centre Negative
Sega Game Gear	9V DC	1.2A	4.75 × 1.7mm		MK-2103 (shared PSU with Saturn in some regions)
Group 4 – 6V DC, 4.75mm × 1.7mm, Centre Negative
Nintendo Game Boy (DMG-01)	6V DC	0.7A	4.75 × 1.7mm		DMG-03 / MGB-005
Group 5 – 9–10V DC, 4.75mm × 1.7mm, Centre Positive
Atari Lynx (Model 1)	9V DC	1.0A	4.75 × 1.7mm		PA-1400
Atari Lynx (Model 2)	9V DC	1.0A	4.75 × 1.7mm		PA-1400
Sega 32X	10V DC	0.85A	4.75 × 1.7mm		MK-1633
Sega Nomad	10V DC	0.85A	4.75 × 1.7mm		MK-1633
Sega Mega Drive / Genesis (Model 2)	10V DC	0.85A	4.75 × 1.7mm		MK-1633
Sega Nomad	10V DC	0.85A	4.75 × 1.7mm		MK-1633
Group 6 – 10V DC, 5.5mm × 2.1mm, Centre Negative
Nintendo Famicom (HVC)	10V DC	0.85A	5.5 × 2.1mm		HVC-002
Nintendo Virtual Boy	10V DC	0.85A	5.5 × 2.1mm		VUE-002
Group 7 – 5V DC, 5.5mm × 2.1mm, Centre Positive
Neo Geo AES (later PRO-POW-3 / E)	5V DC	3.0A	5.5 × 2.1mm		PRO-POW-3 / PRO-POW-E
Neo Geo CD (Front & Top Loader)	5V DC	3.0A	5.5 × 2.1mm		Neo Geo CD PSU
Group 8 – 7.5V DC, 4.0mm × 1.7mm, Centre Negative
Sony PlayStation (PS1)	7.5V DC	2.0A	4.0 × 1.7mm		SCPH-113

Notes & Warnings

• Atari 2600 (VCS) – early units use a simple 9V DC centre-negative PSU at low current. Many modern replacements are compatible, but original adapters are prone to failure with age.
• Atari 7800 – same barrel size and polarity as Atari 2600 but requires more current (1.0A). A 2600 PSU may power it but risk instability.
• Atari Jaguar / Jaguar CD – uses the same PSU spec as Sega Mega Drive 1 (9V DC, centre-negative). Safe cross-compatibility.
• Atari Lynx (Model 1 and Model 2) – both require 9V DC centre-positive. Using a centre-negative adapter (e.g. Spectrum, Master System, Mega Drive Model 1) will damage the system.
• NEC PC Engine / CoreGrafx / TurboGrafx-16 – requires 9V DC centre-negative. Later Duo models draw more current.
• NEC PC Engine Duo / TurboDuo – 9V DC centre-negative, higher current draw (1.5A). Should not be powered with weaker CoreGrafx/TurboGrafx supplies.
• Neo Geo AES – PSU requirements vary by production run. Early PRO-POW-1/2 used 9V centre-negative, later PRO-POW-3/E use 5V centre-positive. Using the wrong adapter can destroy the system.
• Neo Geo CD – requires 5V DC centre-positive at 3A. A very specific PSU; substitutes must exactly match.
• Nintendo Famicom (HVC-002) – requires 10V DC centre-negative. Cannot be safely powered with NES (PAL) or SNES (PAL) adapters.
• Nintendo Game Boy (DMG-01) – uses a 6V DC PSU, centre-negative. Do not use 9V adapters intended for other Nintendo or Sega consoles.
• Nintendo NES (PAL) – same as PAL SNES, but NTSC NES (US/Japan) typically shipped with a 9V AC PSU. Do not interchange with PAL systems.
• Nintendo Super NES (PAL) – uses 9V DC centre-negative. NTSC models often shipped with AC adapters instead of DC, making them incompatible with PAL PSUs.
• Nintendo Virtual Boy – also uses 10V DC centre-negative (same as Famicom). Power requirements are stricter than most Nintendo consoles.
• Sega 32X – same PSU spec as Mega Drive 2. Tower of Power setups (MD + 32X + Mega-CD) require multiple adapters, not a single shared PSU.
• Sega CD (Model 1 & 2) – same PSU spec as Mega Drive 1. Compatible supplies can be interchanged.
• Sega Game Gear – draws a high current; cheap adapters often cause humming in the audio and unstable video.
• Sega Master System – compatible with Mega Drive Model 1 PSU (same voltage, current, and polarity).
• Sega Mega Drive / Genesis Model 1 vs Model 2 – Model 1 is centre-negative, Model 2 is centre-positive. Swapping these power supplies will damage the console.
• Sega Nomad – uses the same PSU as Mega Drive 2 (10V, centre-positive). Do not use a Model 1 PSU.
• Sega Saturn – uses the same barrel as Model 1 Mega Drive but requires more current (1.5A). A weaker PSU may boot the system but cause crashes.
• Sony PlayStation (PS1) – requires 7.5V DC at 2.0A. Using 9V adapters directly can overheat or damage the console. The barrel plug (4.0 × 1.7mm) is smaller than most Sega/Nintendo connectors and not interchangeable.
• ZX Spectrum (16K/48K) – requires a regulated 9V DC centre-negative supply. Original Sinclair PSUs were unregulated and can output up to 14V off-load, risking damage to modern peripherals.
• ZX Spectrum +2 / +2A / +3 – higher current draw (2.1A). A weaker Spectrum 48K PSU is not sufficient.

• General note on amperage – it is safe to use a PSU rated at a higher current (A) than required, but never lower. Voltage and polarity must always match.

PSU Cross-Compatibility

Symbol	Meaning
✓	Safe – barrel fits, voltage/polarity correct, PSU current ≥ system requirement
–	Underpowered – barrel fits, voltage/polarity correct, but PSU current too low (not recommended)
✗	Dangerous – wrong voltage and/or polarity

5.5 × 2.1 mm barrel

PSU Cross-Compatibility Matrix — 5.5 × 2.1 mm barrel

System ▶ PSU ▼	ZX Spectrum +2/+3	Sega Saturn	NEC PC Engine Duo	Nintendo NES (PAL)	Nintendo Super NES (PAL)	Sega Mega Drive 1	Sega Master System	Sega CD	Atari Jaguar	NEC PC Engine	Nintendo Famicom	Nintendo Virtual Boy	Neo Geo AES	Neo Geo CD
ZX Spectrum +2/+3	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✗	✗	✗	✗
Sega Saturn	–	✓	✓	✓	✓	✓	✓	✓	✓	✓	✗	✗	✗	✗
NEC PC Engine Duo	–	✓	✓	✓	✓	✓	✓	✓	✓	✓	✗	✗	✗	✗
Nintendo NES (PAL)	–	–	–	✓	✓	✓	✓	✓	✓	✓	✗	✗	✗	✗
Nintendo Super NES (PAL)	–	–	–	✓	✓	✓	✓	✓	✓	✓	✗	✗	✗	✗
Sega Mega Drive 1	–	–	–	–	–	✓	✓	✓	✓	✓	✗	✗	✗	✗
Sega Master System	–	–	–	–	–	✓	✓	✓	✓	✓	✗	✗	✗	✗
Sega CD	–	–	–	–	–	✓	✓	✓	✓	✓	✗	✗	✗	✗
Atari Jaguar	–	–	–	–	–	✓	✓	✓	✓	✓	✗	✗	✗	✗
NEC PC Engine	–	–	–	–	–	–	–	–	–	✓	✗	✗	✗	✗
Nintendo Famicom	✗	✗	✗	✗	✗	✗	✗	✗	✗	✗	✓	✓	✗	✗
Nintendo Virtual Boy	✗	✗	✗	✗	✗	✗	✗	✗	✗	✗	✓	✓	✗	✗
Neo Geo AES	✗	✗	✗	✗	✗	✗	✗	✗	✗	✗	✗	✗	✓	✓
Neo Geo CD	✗	✗	✗	✗	✗	✗	✗	✗	✗	✗	✗	✗	✓	✓

Header colour	Voltage / Polarity Group
	9 V DC, centre-negative
	10 V DC, centre-negative
	5 V DC, centre-positive

3.5 × 1.35 mm barrel

PSU Cross-Compatibility Matrix — 3.5 × 1.35 mm barrel

System ▶ PSU ▼	ZX Spectrum (16/48K)	Atari 7800	Atari 2600 (VCS)
ZX Spectrum (16/48K)	✓	✓	✓
Atari 7800	–	✓	✓
Atari 2600 (VCS)	–	–	✓

Header colour	Voltage / Polarity Group
	9 V DC, centre-negative

4.75 × 1.7 mm barrel

PSU Cross-Compatibility Matrix — 4.75 × 1.7 mm barrel

System ▶ PSU ▼	Sega Game Gear	Atari Lynx	Sega 32X	Sega Mega Drive 2	Sega Nomad	Nintendo Game Boy (DMG-01)
Sega Game Gear	✓	✗	✗	✗	✗	✗
Atari Lynx	✗	✓	✓	✓	✓	✗
Sega 32X	✗	–	✓	✓	✓	✗
Sega Mega Drive 2	✗	–	✓	✓	✓	✗
Sega Nomad	✗	–	✓	✓	✓	✗
Nintendo Game Boy (DMG-01)	✗	✗	✗	✗	✗	✓

Header colour	Voltage / Polarity Group
	9 V DC, centre-negative (e.g., Sega Game Gear)
	9–10 V DC, centre-positive (e.g., Lynx, MD2, Nomad, 32X)
	6 V DC, centre-negative (e.g., Nintendo Game Boy DMG)

4.0 × 1.7 mm barrel

Only the Sony PlayStation (PS1) uses this connector. No cross-compatibility with other systems.