NEO-AES board: Difference between revisions

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[[File:neo-aes_pcb.jpg|thumb|Picture wanted.]]
First known version of the AES board, made (and maybe assembled) by NEC. Uses the first generation chipset {{Chipname|PRO-B0}}, {{Chipname|PRO-C0}}, {{Chipname|LSPC-A0}}.


First (?) version of the AES board, made (and maybe assembled) by NEC. Uses the first generation chipset ({{Chipname|PRO-B0}}, {{Chipname|PRO-C0}}, {{Chipname|LSPC-A0}}) and exclusively works with [[power requirements|5V power supplies]].
In later use of this board version, a [[video PLL|video cleaner]] board was added.


In late use of this board version, a [[Video PLL]] and the [[NEO-POWER-0]] power supply daughterboards were added on top.
Some consoles also have a metal shield connected to ground.


Some consoles also have an added metal shield connected to ground.
=Voltage protection=
 
The voltage protection circuit changed during the production of the board:
* The first boards simply had no voltage protection. Meaning that using a higher than [[power requirements|5V power supply]] would fry everything.
* Later on, components were added to dump excessive voltage as heat (see below).
* Even later, the [[NEO-POWER-0]] board was added as a factory mod to allow the safe use of 9V power supplies.
 
The voltage protection circuit starts operating as soon as the input voltage goes above 5.4V. If used with a 9V power supply for an extended period of time, it may fail due to excessive heat. Q2 and/or D1 may need to be replaced.
 
[[File:Neo-aes_power.png|400px]]
[[File:Neo-aes_power2.png|400px]]
 
=Board map=
 
[[File:neo-aes.jpg|640px|center]]
 
* 1A: [[Power supply]] barrel jack connector
* 1C: Audio/video output [[pinouts|DIN connector]]
* 1F: Main [[clock]] circuit
* 1I: [[68k user RAM]] chips
* 1J: System latch
* 1KL: [[System ROM]]
* 1OPQ: Analog sound circuit
* 2EF: [[Video DAC]]
* 2Q: {{Chipname|YM3016}}
* 3B: [[Video encoder]] and color burst oscillator
* 3EF: Palette RAM latches
* 3HIJK: [[68k]] CPU
* 3LMNO: {{Chipname|YM2610}} soundchip
* 4F~M: Cartridge [[AES_cartridge_pinout|slot]]
* 4PQ: [[Palette RAM]] chips
* 5CD: {{Chipname|LSPC-A0}}
* 5FG: [[L0 ROM]]
* 5IJK: [[Z80]] CPU
* 6M: [[Z80 RAM]]
* 7B: Slow [[VRAM]] chips
* 7C: [[Reset]] button
* 7H: {{Chipname|PRO-B0}}
* 7K: {{Chipname|PRO-C0}}
* 8E: Fast [[VRAM]] chips
* 8OPQR: [[Memory card]] slot
* 9C: Voltage protection circuit
* 9EF: [[Joypad]] input [[CRE401|filters]]
* 9HIJK: Analog sound circuit
* 9LM: More joypad input filters
* 10B: Power switch
* 10F: [[Pinouts#Joypad_ports|P1 connector]]
* 10H: Headphone 3.5mm stereo jack connector
* 10J: Headphone volume slider
* 10M: [[Pinouts#Joypad_ports|P2 connector]]


[[Category:Cartridge systems]]
[[Category:Cartridge systems]]
[[Category:Repairs]]

Latest revision as of 01:48, 28 August 2019

First known version of the AES board, made (and maybe assembled) by NEC. Uses the first generation chipset PRO-B0, PRO-C0, LSPC-A0.

In later use of this board version, a video cleaner board was added.

Some consoles also have a metal shield connected to ground.

Voltage protection

The voltage protection circuit changed during the production of the board:

  • The first boards simply had no voltage protection. Meaning that using a higher than 5V power supply would fry everything.
  • Later on, components were added to dump excessive voltage as heat (see below).
  • Even later, the NEO-POWER-0 board was added as a factory mod to allow the safe use of 9V power supplies.

The voltage protection circuit starts operating as soon as the input voltage goes above 5.4V. If used with a 9V power supply for an extended period of time, it may fail due to excessive heat. Q2 and/or D1 may need to be replaced.

Board map

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