Work RAM

WRAM (Work RAM) serves as the SNES' main memory. It is 128K x 8 bits (131,072 bytes) in size. It has part number 21326. [3]

Even though WRAM has both Address Bus A and Address Bus B connected to it, the chip can only pay attention to one at a time, so WRAM-to-WRAM DMA isn't possible.

WRAM is left intact by the Reset_Button. [2]

The WRAM chip is straddling regions C1 and D1 in the jwdonal schematic

References

• [1] https://problemkaputt.de/fullsnes.htm#snesmemoryworkramaccess
• [2] https://problemkaputt.de/fullsnes.htm#snescontrollersotherinputs
• page 1 of Book II, "Super NES Parts List" in the official Nintendo development manual
• https://archive.org/details/SNESDevManual/book1/page/n97