4164/41256 RAM Modification - Revision history

Braedel: /* Modify the MPU */

2026-09-12T13:55:56Z

Modify the MPU

← Older revision		Revision as of 13:55, 12 September 2026
Line 44:		Line 44:

	* Note — The polarizing key is on Pin 4. With the mod, if the connector is reversed/flipped it can't be plugged in.		* Note — The polarizing key is on Pin 4. With the mod, if the connector is reversed/flipped it can't be plugged in.
	* Note — Pin 1 is on the right and Pin 9 is on the left.		* Note — Pin 1 is on the right and Pin 9 is on the left.

	[[File:Modified_Power_Connector.jpg\|center\|800px\|Pins 5 and 9 cut]]		[[File:Modified_Power_Connector.jpg\|center\|800px\|Pins 5 and 9 cut]]

	'''Step 2''' — Modify the solder side of the MPU		'''Step 2''' — Modify the solder side of the MPU
			*In this view, Pin 1 is on the left and Pin 9 on the right.
	* '''Use a cut off pin to bridge pins 5 and 6!'''		* '''Use a cut off pin to bridge pins 5 and 6!'''

Braedel: /* Modify the MPU */

2026-09-12T13:54:59Z

Modify the MPU

← Older revision		Revision as of 13:54, 12 September 2026
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	'''Step 2''' — Modify the solder side of the MPU		'''Step 2''' — Modify the solder side of the MPU
			* '''Use a cut off pin to bridge pins 5 and 6!'''

	[[File:Board_Mod_-_Solder_Side.jpg\|center\|800px\|Solder-side MPU modification]]		[[File:Board_Mod_-_Solder_Side.jpg\|center\|800px\|Solder-side MPU modification]]

Braedel: /* Modify the MPU */

2026-09-12T13:53:37Z

Modify the MPU

← Older revision		Revision as of 13:53, 12 September 2026
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	* '''The goal is to have +5 on Pins: 1, 8 and 9. Ground stays on Pin 16'''		* '''The goal is to have +5 on Pins: 1, 8 and 9. Ground stays on Pin 16'''
	* '''This mod does NOT damage the PCB; no cutting traces, etc. Everything can easily be undone/reverted!'''		* '''This mod does NOT damage the PCB; no cutting traces, etc. Everything can easily be undone/reverted!'''
			* '''No change to wiring harness or power supply needed - board will work in all cabinets'''

Braedel: /* Modify the MPU */

2026-09-12T13:51:32Z

Modify the MPU

← Older revision		Revision as of 13:51, 12 September 2026
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	* '''Substitute +5v on Pins 1 and 8''' (If we left these unconnected/floating, the address value would randomly change)		* '''Substitute +5v on Pins 1 and 8''' (If we left these unconnected/floating, the address value would randomly change)
	* '''The goal is to have +5 on Pins: 1, 8 and 9. Ground stays on Pin 16'''		* '''The goal is to have +5 on Pins: 1, 8 and 9. Ground stays on Pin 16'''
	* '''This mod does NOT damage the PCB; ~~not~~ cutting traces, etc. Everything can easily be undone!'''		* '''This mod does NOT damage the PCB; no cutting traces, etc. Everything can easily be undone/reverted!'''

Braedel: /* Modify the MPU */

2026-09-12T13:50:56Z

Modify the MPU

← Older revision		Revision as of 13:50, 12 September 2026
Line 33:		Line 33:
	* '''Substitute +5v on Pins 1 and 8''' (If we left these unconnected/floating, the address value would randomly change)		* '''Substitute +5v on Pins 1 and 8''' (If we left these unconnected/floating, the address value would randomly change)
	* '''The goal is to have +5 on Pins: 1, 8 and 9. Ground stays on Pin 16'''		* '''The goal is to have +5 on Pins: 1, 8 and 9. Ground stays on Pin 16'''
			* '''This mod does NOT damage the PCB; not cutting traces, etc. Everything can easily be undone!'''


	Original MPU Power Connector Pinout		Original MPU Power Connector Pinout

Braedel at 12:22, 12 September 2026

2026-09-12T12:22:51Z

← Older revision		Revision as of 12:22, 12 September 2026
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	== Modify the MPU ==		== Modify the MPU ==
	What we need to do: For the 4164/41256 to work, we need to accomplish a few things.		What we need to do: For the 4164/41256 to work, we need to accomplish a few things.
	* '''Remove the -5v from Pin 1'''
			* '''Remove the -5v from Pin 1'''
	* '''Remove the +12v from Pin 8'''		* '''Remove the +12v from Pin 8'''
	* '''Substitute +5v on Pins 1 and 8 (If we left these unconnected/floating, the address value would randomly change~~'''~~		* '''Substitute +5v on Pins 1 and 8''' (If we left these unconnected/floating, the address value would randomly change)
	* '''The goal is to have +5 on Pins: 1,8 and 9. Ground stays on Pin 16		* '''The goal is to have +5 on Pins: 1, 8 and 9. Ground stays on Pin 16'''

	Original MPU Power Connector Pinout		Original MPU Power Connector Pinout

	[[File:MPU_Unmod_Power_-_Noted.png\|center\|800px\|Original MPU Power Connector Pinout]]		[[File:MPU_Unmod_Power_-_Noted.png\|center\|800px\|Original MPU Power Connector Pinout]]

	'''Step 1''' — Cut pins 5(+12 Regulated) and 9(~~-5v~~) * Keep one of the cut off pins *		'''Step 1''' — Cut pins 5 (+12 Regulated) and 9 (−5 V). Keep one of the cut-off pins.
	* Note - The ~~'Polarizing Key~~ is on Pin 4. With the mod, if the connector is reversed/flipped it can't be plugged in *
	* Note - Pin 1 is on the right and Pin 9 is on the left *		* Note — The polarizing key is on Pin 4. With the mod, if the connector is reversed/flipped it can't be plugged in.
			* Note — Pin 1 is on the right and Pin 9 is on the left.

	[[File:Modified_Power_Connector.jpg\|center\|800px\|Pins 5 and 9 cut]]		[[File:Modified_Power_Connector.jpg\|center\|800px\|Pins 5 and 9 cut]]

			'''Step 2''' — Modify the solder side of the MPU

			[[File:Board_Mod_-_Solder_Side.jpg\|center\|800px\|Solder-side MPU modification]]

	== See also ==		== See also ==
	* [[Hardware - General]]		* [[Hardware - General]]
	* [[Battery Damage]]		* [[Battery Damage]]

Braedel: /* Modify the MPU */

2026-09-12T04:50:25Z

Modify the MPU

← Older revision		Revision as of 04:50, 12 September 2026
Line 38:		Line 38:
	'''Step 1''' — Cut pins 5(+12 Regulated) and 9(-5v) * Keep one of the cut off pins *		'''Step 1''' — Cut pins 5(+12 Regulated) and 9(-5v) * Keep one of the cut off pins *
	* Note - The 'Polarizing Key is on Pin 4. With the mod, if the connector is reversed/flipped it can't be plugged in *		* Note - The 'Polarizing Key is on Pin 4. With the mod, if the connector is reversed/flipped it can't be plugged in *
			* Note - Pin 1 is on the right and Pin 9 is on the left *

	[[File:Modified_Power_Connector.jpg\|center\|800px\|Pins 5 and 9 cut]]		[[File:Modified_Power_Connector.jpg\|center\|800px\|Pins 5 and 9 cut]]

Braedel: /* Modify the MPU */

2026-09-12T04:49:12Z

Modify the MPU

← Older revision		Revision as of 04:49, 12 September 2026
Line 37:		Line 37:

	'''Step 1''' — Cut pins 5(+12 Regulated) and 9(-5v) * Keep one of the cut off pins *		'''Step 1''' — Cut pins 5(+12 Regulated) and 9(-5v) * Keep one of the cut off pins *
			* Note - The 'Polarizing Key is on Pin 4. With the mod, if the connector is reversed/flipped it can't be plugged in *

	[[File:Modified_Power_Connector.jpg\|center\|800px\|Pins 5 and 9 cut]]		[[File:Modified_Power_Connector.jpg\|center\|800px\|Pins 5 and 9 cut]]

Braedel: /* Modify the MPU */

2026-09-12T04:46:52Z

Modify the MPU

← Older revision		Revision as of 04:46, 12 September 2026
Line 31:		Line 31:
	* '''Remove the +12v from Pin 8'''		* '''Remove the +12v from Pin 8'''
	* '''Substitute +5v on Pins 1 and 8 (If we left these unconnected/floating, the address value would randomly change'''		* '''Substitute +5v on Pins 1 and 8 (If we left these unconnected/floating, the address value would randomly change'''
	* '''The goal is to have +5 on Pins: 1,8 and 9 ~~and ground~~ stays on Pin 16		* '''The goal is to have +5 on Pins: 1,8 and 9. Ground stays on Pin 16
	Original MPU Power Connector Pinout		Original MPU Power Connector Pinout

Braedel: /* Modify the MPU */

2026-09-12T04:46:15Z

Modify the MPU

← Older revision		Revision as of 04:46, 12 September 2026
Line 30:		Line 30:
	* '''Remove the -5v from Pin 1'''		* '''Remove the -5v from Pin 1'''
	* '''Remove the +12v from Pin 8'''		* '''Remove the +12v from Pin 8'''
	* '''Substitute +5v on Pins 1 and 8 (If we left these unconnected/~~Floating~~, the address value would randomly change'''		* '''Substitute +5v on Pins 1 and 8 (If we left these unconnected/floating, the address value would randomly change'''
			* '''The goal is to have +5 on Pins: 1,8 and 9 and ground stays on Pin 16
	Original MPU Power Connector Pinout		Original MPU Power Connector Pinout