Retro Room’s NES PCBs are JUST FINE
I was asked by The Retro Room to inspect their game boards for any voltage irregularities. These boards will be used for fulfillment of Annalog, a recent kickstarter. The board is reminiscent of MindKids boards I’ve seen on AliExpress, but not exactly the same.
I popped the board into a set of loose shells I have around for testing and the game loaded up a treat, save game functionality also in working order.
So what’s up? Well, recently, you see, you may or may not have heard, but a certain company shipped cartridges with 3.3v chips on their board whilst the NES is very much a 5 volt kind of machine. There is no real consensus on what damage, if any, this could cause chips and components in either cartridge or console. But 80 hundred people think it is evil and that all of us homebrewers are possibly performing this practice ourselves!
Front side of Board in Question:
#1 - Two AMI29F400ABT programmable rom chips holding 4 megabits (or 512 kilobytes) each. The one on the left is probably graphics, the other software, both operating at 5 volts.
#2 - Atmel ATTINY13A microcontroller which mimics the proprietary CIC lockout chip handshake, keeping your NES from blinking. Operates between 2.7 and 5.5 volts.
# 3 - SMD133 - MMC3 mapper chip clone. Operating on 2.5-6.5 volts.
#4 - Unknown 3 prong surface mount thingy that says CAZB which seemingly means nothing. Could be a transistor or voltage regulater — could be over engineering like the cascade of resistors, caps, and diodes between here and yonder #2.
#5 - TI 61AKQ2M HC00 - probably a quad NAND gate (because of the HC00). Not sure why it’s here, but it operates between 2 and 6 volts.
Back side of Board in Question:
This is where your saved games live. 🏠
#6 - Mitsubishi M5M5256DFP is 32 kilobytes of static ram, requires 5 volts for full operation.
#7 - Today I Learned the CR2032 coin cell battery that keeps the static ram alive and remembering is only 3 volts. And that's the standard. 🤔
This is Langel Bookbinder of LoBlast signing off on these boards being as console friendly as they should be. Have a mighty, mighty day!
