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Work RAM: Difference between revisions

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[[File:wram schematic.png|thumb|The WRAM chip is straddling regions C1 and D1 in the [[jwdonal schematic]]]]
[[File:wram schematic.png|thumb|The WRAM chip is straddling regions C1 and D1 in the [[jwdonal schematic]]]]


'''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]
'''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. <sup>[3]</sup>


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.
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 a [[Reset]]. [2]  But, Nintendo still recommendeds checking to make sure the contents are correct after a reset.  [5]
WRAM is left intact by a [[Reset]]. <sup>[2]</sup> But, Nintendo still recommendeds checking to make sure the contents are correct after a reset.  <sup>[5]</sup>


[[Category:SNES Hardware]]
[[Category:SNES Hardware]]

Revision as of 00:34, 15 July 2023

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

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 a Reset. [2] But, Nintendo still recommendeds checking to make sure the contents are correct after a reset. [5]

References

  1. https://problemkaputt.de/fullsnes.htm#snesmemoryworkramaccess
  2. https://problemkaputt.de/fullsnes.htm#snescontrollersotherinputs
  3. page 1 of Book II, "Super NES Parts List" in the official Nintendo development manual
  4. page 2-22-1 of Book II, lbid
  5. caution #11: page 2-24-3 of Book I