Type an address to search for nearby blocks
Whitepaper
Explore More
Sign Up / Log In
Semiconductor History | Ricoh Ikeda — 5A22 Keeps the Super Famicom Familiar but Slow
· 1990-11
Personal memoryBy kevin · · updated · Report an issue
Search by address
Search
Loading...
Highlighted Moments
Featured Memories
Find memories left by people near you.
Distribute Bounty
Total to distribute
0 MR
Qualifying memories
0
This will distribute the bounty equally among all qualifying memories. This action cannot be undone.
Cancel Bounty
Refund amount
0 MR
Are you sure you want to cancel this bounty? The remaining amount will be refunded to your account.
Success!
Operation completed successfully.
Error
Something went wrong.
Back to map
Back
This memory is part of
Semiconductor History | Ricoh Ikeda — 5A22 Keeps the Super Famicom Familiar but Slow
kevin
11/21/1990
Listen
Directions
On 21 November 1990, Nintendo released the Super Famicom in Japan. At its centre sat the S-CPU, Ricoh’s custom 5A22 processor—an evolutionary choice that helped Nintendo move beyond the Famicom without abandoning the programming lineage that had made its first console practical.
The 5A22 was built around Western Design Center’s 65C816 architecture. It could perform eight- or sixteen-bit operations and address 16 megabytes through a 24-bit address space, while retaining an eight-bit external data path.
That combination gave developers familiar 6502-family ideas in a roomier machine, though it did not make Super Famicom software directly compatible with Famicom programs.
The good part was everything Ricoh and Nintendo put around the core. The 5A22 integrated direct-memory-access controls, horizontal-blank DMA, multiplication and division hardware, interrupt timing, and controller interfaces.
DMA could move blocks while pausing the CPU; HDMA could change selected graphics registers across scanlines. Those features let a modest processor coordinate elaborate backgrounds, colour effects, and sprites with less repetitive software work.
It also extended a valuable industrial relationship. Ricoh’s Famicom chips had already turned a large Nintendo order into a bridge toward merchant semiconductors.
The Super Famicom kept that custom-silicon partnership alive: Nintendo obtained a processor shaped around its console, while Ricoh supplied another high-volume consumer LSI rather than competing only with general-purpose CPUs.
The bad part was speed. The NTSC console’s master clock was about 21.477 MHz, but the 5A22 did not execute at one simple headline rate.
Internal cycles took six master clocks, while different memory regions imposed six-, eight-, or twelve-clock accesses—roughly 3.58, 2.68, or 1.79 MHz. Performance therefore depended on where code and data lived, and the eight-bit bus serialized transfers that a wider design might have completed sooner.
That compromise aged visibly. Games could exploit DMA and the powerful picture processors, yet CPU-heavy logic and three-dimensional geometry quickly exposed the limit.
Nintendo’s later Super FX cartridges—and faster enhancement processors such as SA-1—showed both sides of the architecture: the base machine was flexible enough to accept help, but ambitious software sometimes had to bring new silicon with it.
The cover photograph shows a later “S-CPU B” 5A22-02 package, not the original 1990 launch revision. The second image shows the chip among the PPU, sound, and memory devices on a later SNS-CPU-GPM-02 motherboard, providing system context rather than a launch-day board.
The pin marks today’s Nisshinbo Micro Devices Ikeda Office, successor to Ricoh’s semiconductor operations. It is an institutional lineage marker, not a claim that this exact building or room designed the 5A22.
Sources:
Nintendo, “Iwata Asks: Star Fox 64 3D”: https://www.nintendo.com/en-za/Iwata-Asks/Iwata-Asks-Star-Fox-64/Vol-1-Star-Fox-64-3D/2-It-ll-Be-Easy-to-Make-/2-It-ll-Be-Easy-to-Make--220848.html
Western Design Center, W65C816S datasheet: https://www.westerndesigncenter.com/wdc/documentation/w65c816s.pdf
Nintendo, Super Nintendo Entertainment System Development Manual, Book I: https://floating.muncher.se/bot/manual/book1_text.pdf
Anomie, “SNES timing.txt”: https://github.com/gilligan/snesdev/blob/master/docs/timing.txt
SNESdev Wiki, “Multiplication”: https://snes.nesdev.org/wiki/Multiplication
Photos:
Yaca2671, “5A22-02 01.jpg,” CC BY-SA 3.0: https://commons.wikimedia.org/wiki/File:5A22-02_01.jpg
htomari, “Nintendo SNS-CPU-GPM-02 motherboard.jpg,” CC BY-SA 2.0: https://commons.wikimedia.org/wiki/File:Nintendo_SNS-CPU-GPM-02_motherboard.jpg
Related Memories
Memory Marks
You marked this memory as
InspiringHeartwarmingEnjoyableSolemn!
You have 0 Memory Marks left to give today
Nice work! You have given out all your memory marks today!
Come back tomorrow or own more Blox to get more daily Memory Marks!
Thank you for alerting us of this Memory. We will review within the next 24 hours.
Save to Collection
Semiconductor History | Ricoh Ikeda — 5A22 Keeps the Super Famicom Familiar but Slow
New Collection
No collections yet
Create one above to get started
0
Do you want to remove this memory from the collection?
Do you want to save
changes?
changes?
The changes you made have been saved
Root to Blockchain
Do you want to root this memory to IPFS with 1 Metablox Coin?
You currently have Metablox Coins
Root to Blockchain
You need 1 Metablox Coin to root this memory to IPFS.
You don't have enough Metablox Coins
Uploading to Blockchain…
Preparing your memory for IPFS. Please don't close this window.
Upload Failed
Something went wrong while connecting to IPFS. Your Metablox Coin was not deducted. Please try again later.
Push New Version
Create a new version of this memory, preserving its current state on IPFS.
Cost: 1 Metablox Coin
You currently have Metablox Coins
New Version is on its way to the Blockchain!
Your updated memory will be available on IPFS within 10 minutes.
Your Memory is on its way to the Blockchain!
You'll be able to access it on IPFS within 10 minutes.
Uploading your memories
Are you sure you want to
delete this memory?
delete this memory?
Are you sure you want to delete this memory?
Keep
Delete
Take Photo
Add your photos
Add more photos
Preview your memory
Uploading your memory
You have successfully preserved a memory!
We detected that you have a Blox in your crypto wallet! We will import the Blox into your account.
Click on done below to complete the import.
Welcome Back!
Sign in to preserve cherished moments
Don't have an account?
Welcome!!
Sign up and start preserving cherished moments
Password Recovery
Enter the email associated with your account
Check your inbox
Use the link in the email to reset your password
Would you like to level up
?
?
Cost
MetaRent
Would you like to level up
?
?
Cost
MetaRent
reached Level !!
MetaRent / day
Max Storage
Coins Earned
+
reached Level !!
MetaRent / day
Max Storage
Coins Earned
+
Add your
photos
Tell us about this
Moment
Description (Optional)
/140 characters
Where is this moment?
location
Try searching for: Golden Gate Bridge, Miami Beach, or an address.
Uploading your moment
You have successfully preserved a memory!
Your moment is now
on .
You have successfully preserved a memory!
Your moment is now
on .
Uploading
exoangel
Hidden in 91hrs
Global Blox
Aug 31, 2026
Sprouts sandwich
exoangel
Hidden in 66hrs
Global Blox
Aug 30, 2026
Sunday beach time
exoangel
Hidden in 67hrs
Global Blox
Aug 29, 2026
Weeekend scene
exoangel
Hidden in 45hrs
Global Blox
Aug 28, 2026
Feeding the birds
exoangel
Hidden in 21hrs
Global Blox
Aug 28, 2026
Shrimp fried rice
You marked this moment as
InspiringHeartwarmingEnjoyableSolemn!
You have 0 Memory Marks left to give today
Nice work! You have given out all your memory marks today!
Come back tomorrow or own more Blox to get more daily Memory Marks!
Choose your payment method
Buy with Metablox Credit
Do you want to mint Blox with Metablox Credit?
Which Crypto would you like to use?
Payment confirmed!
Your Blox is being minted on-chain. This usually takes under a minute.
Check your Metamask extension
Step 1: Click "Confirm" to give Metamask permission to access your crypto
Important: When the extension shows up, scroll down and hit "Confirm" to mint.
Important: You must change the suggested gas fee to High in order to process the transaction.
DO NOT refresh or close the page before seeing this.
We're processing your order...
This sometimes takes a few mins.
Please bear with us 💪
DO NOT refresh or close the page
Contact the Devs
We're very sorry this happened
Your transaction record has been submitted to our team. We'll solve this situation ASAP
Purchase Confirmed!
Your Blox is being minted on-chain and will appear in your profile shortly.
Log in or sign up to claim your Blox.
How many credits do you want to buy?
$100 USD = 1 Metablox Credit = 1 Blox.
Use Metablox Credit to mint any Blox you want on the map.
expand_more