PB6 - PCBs

JAMMA version

Revision:2018.08.08 K5891

Schema

Comments

• The H3 CPU can support up to 2GB ram.
• There are two RAM slots on the motherboard, but only one is used.
• The CGA signal seems generated in two steps: HDMI to VGA/CGA (bootX ?), then amplified/filtered (U7 to U15 pins 1-3).
• The ATMLH830 eeprom (2KB) seems to be used to store the settings.
• The 12V seems to be used only for the Audio amplifier stage (JAMMA pin 6 to TDA2003L pin 5) and the fan power supply.
• You can switch on the Pandora Box Jamma by powering it only with the 5V.

BUT /!\ Careful: don't do that at home. The 12V fan is not powered, you could seriously damage the PCB/CPU. A (bad) solution can be to put the 5V on the 12V, this will allow the fan to be powered.

How to

• Pandora's Box 6 PCB EEProms dump

References

• H5TQ2G63GFR 2Gb DDR SDRAM (256MB) (256MB = 2Gb).
• H3 Datasheet.
• HC245 Octal 3-State Noninverting Bus Transceiver.
• TDA2003L 10W Car Radio Audio Amplifier
• ATMLH830 datasheet alternative

H3 processor pinouts

Inputs