RAM chip: Difference between revisions

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[[File:Cxk58256mm12.jpg|thumb|Sony CXK58256 120ns RAM]]
[[MVS hardware|MVS]] RAM chips often fry due to overvoltage from a badly adjusted or failing cab power supply. It appears that the most common failure mode is the inability to write new data, resulting in errors during [[system self-test]] at the beginning of address ranges.
 
NeoGeo use multiples SRAM (Static RAM) types:
* Work, Backup and lower Video RAM chips are 256k SRAM (5 volt, JEDEC pin compatible, 32K x 8bit) and only differ by speed. They have "256" or "257" in their markings
* Fast Video RAM (VRAM $8000~$87FF) chips are embedded into a Neo-GRC chip or 16k SRAM (5 volt, 24pin DIP, 2K x 8bit, 35ns or faster), however some [[MVS hardware|MVS]] and [[AES hardware|AES]] allow the use of a 28pin SRAM by the use of a jumper.
* Sound RAM chips are 16k SRAM (5 volt, 24pin DIP, 2K x 8bit, 150ns or faster) - fast Video RAM chip can be used as a replacement as they are faster (35ns).
* Palette RAM chips are 64k SRAM (5 volt, JEDEC pin compatible, 8K x 8bit, 120ns or faster)
 
See [[memory speed]] for details about speed grades.


[[MVS hardware|MVS]] RAM chips often fry due to overvoltage from a badly adjusted or failing cab power supply. It appears that the most common failure mode is the inability to write new data, resulting in errors during [[system self-test]] at the beginning of address ranges.


Basically, all NeoGeo RAM chips with "256" or "257" in their markings are 8-bit 32kB RAMs.
==Pictures==
 
<gallery>
File:Cxk58256mm12.jpg|Sony CXK58256 120ns<br />Work, Backup and Video RAM
File:CXK5864BSP-10L.jpg|Sony CXK5864BSP 100ns<br />Palette RAM
File:CXK5814P-35L.jpg|Sony CXK5814P 35ns<br />fast Video RAM
File:BR6216B-10LL.jpg|BR6216B 100ns<br />Sound RAM
File:BR6265BF-10SL.jpg|BR6265BF 100ns<br />Palette RAM
File:BR6216A-15L.jpg|BR6216A 150ns<br />Sound RAM
</gallery>


==Pinout and cross-refence==
==Pinout and cross-refence==


To do.
===Work, Backup, Video===
* CXK58256MM-12
* KM62256CLG-7
* W24258S-70LE
* CXK58257AM-12LX
* any "43256", "62256", CXK58257


==Speed grade==
===Fast Video===
* CXK5814P-35L
* CXK5863P-35L (only on boards that allow the use by changing the jumper)
* any CXK5814, CYC128A, 6116


The number after the - indicates the speed (max time between /RD going low and stable data):
===Palette===
* CXK5864BSP-10L
* LH5168N-80L
* XLJ6265AF-10SL
* BR6265BF-10SL
* "6164" for generic device test
 
===Sound===
* BR6116-100
* BR6216B-10LL
* BR6216A-10LL
* any CXK5814, CYC128A, 6116
 
==Replacement==
 
For '''Work, Backup and Video RAM''' look for 256kbit SRAM, 5 volt, JEDEC pin compatible, 32K x 8bit, 120ns or faster in 28 pin SOIC package (not SOJ).
Cypress, ISSI, UMC and Lyontek still make them and most today are 45ns, so any will do. This includes 62256, 43256, cxk58257, and others.
 
 
For '''fast Video RAM''' look for 16kbit SRAM, 5 volt, JEDEC pin compatible, 2K x 8bit, 35ns or faster in 24pin DIP package.<br />
For '''Sound RAM''' look for 16kbit SRAM, 5 volt, JEDEC pin compatible, 2K x 8bit, 150ns or faster in 24pin DIP package. <br />
This includes the CXK5814, CYC128A, and 6116 ICs, provided they are fast enough.
 
 
For '''Palette RAM''' chips
The can be replaced by 64k RAM chips off of old 386/486 motherboards (fast cache).
This includes the CXK5864BSP-10L 28 pin DIP and LH5168N-80L 28 pin SOIC
 
==Chips types and locations==
 
===MV-1===
* Work: CXK58256MM-12, G3 & H3
* Backup: CXK58256MM-12, H5 & H6
* Video: CXK58256MM-12, G4 & H4
* fast Video: CXK5814P-35L, C5 & D5
* Palette: CXK5864BSP-10L, H9 & H10
* Sound: BR6116-100, H1
 
===MV-1A===
* Work: KM62256CLG-7, RAM1 & RAM2
* Backup: KM62256CLG-7, RAM3 & RAM4
* Video: KM62256CLG-7, RAM5 & RAM6
* fast Video: none
* Palette: LH5168N-80L, BR6265BF-10SL, RAM7 & RAM8
* Sound: BR6216B-10LL, RAM9
 
===MV-1B===
* Work: KM62256CLG-7, RAM1 & RAM2
* Backup: KM62256CLG-7, RAM3 & RAM4
* Video: KM62256CLG-7, RAM5 & RAM6
* fast Video: none
* Palette: none
* Sound: BR6216B-10LL, RAM7
 
===MV-1C===
* Work: W24258S-70LE, RAM1 & RAM3
* Backup: W24258S-70LE, RAM2 & RAM4
* Video: W24258S-70LE, RAM5 & RAM6
* fast Video: none
* Palette: none
* Sound: none
 
===MV1FS===
* Work: CXK58257AM-12LX, H4 & H5
* Backup: CXK58257AM-12LX, H6 & H7
* Video: CXK58257AM-12LX, B4 & B5
* fast Video: CXK5814P-35L, C6 & D6
* Palette: CXK5864BSP-10, H8 & H8
* Sound: BR6116-10, K3
 
===MV1FZ & MV1FZS===
* Work: KM62256CLG-7, RAM1 & RAM2
* Backup: KM62256CLG-7, RAM3 & RAM4
* Video: KM62256CLG-7, RAM5 & RAM6
* fast Video: CXK5814P-35L, RAM7 &RAM8
* Palette: XLJ6265AF-10SL, RAM9 & RAM10
* Sound: BR6216B-10LL, RAM11
 
===MV2FS===
* Work: LH52B256N-70LL, D3 & D4
* Backup: LH52B256N-70LL, G1 & G2
* Video: LH52B256N-70LL, C7 & C8
* fast Video: CXK5814P-35L, C9 & D9
* Palette: CXK5864BSP-10L, B8 & B8
* Sound: BR6216B-10LL, K11
 
===MV2-01===
* Work: LH52B256N-70LL, E5 & E6
* Backup: LH52B256N-70LL, H3 & H4
* Video: LH52B256N-70LL, F13 & G13
* fast Video: CXK5814P-35L, F12 & G12
* Palette: CXK5864BSP-10L, B9 & C9
* Sound: BR6216B-10LL, BR6216A-10LL, K13
 
===MV-4F===
* Work: CXK58256MM-12L, G9 & H9
* Backup: CXK58256MM-12L, D9 & E9
* Video: CXK58256MM-12L, K9 & L9
* fast Video: CXK5814P-35L, L11 & M11
* Palette: CXK5864BSP-10L, F4 & H4
* Sound: BR6216B-10LL, L1
 
===MV-6===
* Work: H9 (lower) & J9 (upper)
* Backup: E9 (upper) & F9 (lower)
* Video: L9 & K9
* fast Video: CXK5814P-35L, M11 & N11
* Palette: CXK5864BSP-10L, G4 & H4
* Sound: BR6116-100, M1


* 15: 150ns
* 12: 120ns
* 10: 100ns
* 70: 70ns
* 45: 45ns


Speed grade must absolutely be equal or less to replaced RAM chip.


==Replacement==


Look for 5 volt, 32kB (32K x 8bit) / 256kbit SRAM (Static RAM) with the right speed grade (most today are 45ns, so any will do) in 28 pin SOIC package. Cypress, ISSI and Lyontek still make them, they go for about $2.50.


[[Category:Chips]]
[[Category:Chips]]
[[Category:Repairs]]
[[Category:Repairs]]

Latest revision as of 11:38, 27 April 2022

MVS RAM chips often fry due to overvoltage from a badly adjusted or failing cab power supply. It appears that the most common failure mode is the inability to write new data, resulting in errors during system self-test at the beginning of address ranges.

NeoGeo use multiples SRAM (Static RAM) types:

  • Work, Backup and lower Video RAM chips are 256k SRAM (5 volt, JEDEC pin compatible, 32K x 8bit) and only differ by speed. They have "256" or "257" in their markings
  • Fast Video RAM (VRAM $8000~$87FF) chips are embedded into a Neo-GRC chip or 16k SRAM (5 volt, 24pin DIP, 2K x 8bit, 35ns or faster), however some MVS and AES allow the use of a 28pin SRAM by the use of a jumper.
  • Sound RAM chips are 16k SRAM (5 volt, 24pin DIP, 2K x 8bit, 150ns or faster) - fast Video RAM chip can be used as a replacement as they are faster (35ns).
  • Palette RAM chips are 64k SRAM (5 volt, JEDEC pin compatible, 8K x 8bit, 120ns or faster)

See memory speed for details about speed grades.


Pictures

  • Sony CXK58256 120ns Work, Backup and Video RAM

    Sony CXK58256 120ns
    Work, Backup and Video RAM

  • Sony CXK5864BSP 100ns Palette RAM

    Sony CXK5864BSP 100ns
    Palette RAM

  • Sony CXK5814P 35ns fast Video RAM

    Sony CXK5814P 35ns
    fast Video RAM

  • BR6216B 100ns Sound RAM

    BR6216B 100ns
    Sound RAM

  • BR6265BF 100ns Palette RAM

    BR6265BF 100ns
    Palette RAM

  • BR6216A 150ns Sound RAM

    BR6216A 150ns
    Sound RAM

Pinout and cross-refence

Work, Backup, Video

  • CXK58256MM-12
  • KM62256CLG-7
  • W24258S-70LE
  • CXK58257AM-12LX
  • any "43256", "62256", CXK58257

Fast Video

  • CXK5814P-35L
  • CXK5863P-35L (only on boards that allow the use by changing the jumper)
  • any CXK5814, CYC128A, 6116

Palette

  • CXK5864BSP-10L
  • LH5168N-80L
  • XLJ6265AF-10SL
  • BR6265BF-10SL
  • "6164" for generic device test

Sound

  • BR6116-100
  • BR6216B-10LL
  • BR6216A-10LL
  • any CXK5814, CYC128A, 6116

Replacement

For Work, Backup and Video RAM look for 256kbit SRAM, 5 volt, JEDEC pin compatible, 32K x 8bit, 120ns or faster in 28 pin SOIC package (not SOJ). Cypress, ISSI, UMC and Lyontek still make them and most today are 45ns, so any will do. This includes 62256, 43256, cxk58257, and others.


For fast Video RAM look for 16kbit SRAM, 5 volt, JEDEC pin compatible, 2K x 8bit, 35ns or faster in 24pin DIP package.
For Sound RAM look for 16kbit SRAM, 5 volt, JEDEC pin compatible, 2K x 8bit, 150ns or faster in 24pin DIP package.
This includes the CXK5814, CYC128A, and 6116 ICs, provided they are fast enough.


For Palette RAM chips The can be replaced by 64k RAM chips off of old 386/486 motherboards (fast cache). This includes the CXK5864BSP-10L 28 pin DIP and LH5168N-80L 28 pin SOIC

Chips types and locations

MV-1

  • Work: CXK58256MM-12, G3 & H3
  • Backup: CXK58256MM-12, H5 & H6
  • Video: CXK58256MM-12, G4 & H4
  • fast Video: CXK5814P-35L, C5 & D5
  • Palette: CXK5864BSP-10L, H9 & H10
  • Sound: BR6116-100, H1

MV-1A

  • Work: KM62256CLG-7, RAM1 & RAM2
  • Backup: KM62256CLG-7, RAM3 & RAM4
  • Video: KM62256CLG-7, RAM5 & RAM6
  • fast Video: none
  • Palette: LH5168N-80L, BR6265BF-10SL, RAM7 & RAM8
  • Sound: BR6216B-10LL, RAM9

MV-1B

  • Work: KM62256CLG-7, RAM1 & RAM2
  • Backup: KM62256CLG-7, RAM3 & RAM4
  • Video: KM62256CLG-7, RAM5 & RAM6
  • fast Video: none
  • Palette: none
  • Sound: BR6216B-10LL, RAM7

MV-1C

  • Work: W24258S-70LE, RAM1 & RAM3
  • Backup: W24258S-70LE, RAM2 & RAM4
  • Video: W24258S-70LE, RAM5 & RAM6
  • fast Video: none
  • Palette: none
  • Sound: none

MV1FS

  • Work: CXK58257AM-12LX, H4 & H5
  • Backup: CXK58257AM-12LX, H6 & H7
  • Video: CXK58257AM-12LX, B4 & B5
  • fast Video: CXK5814P-35L, C6 & D6
  • Palette: CXK5864BSP-10, H8 & H8
  • Sound: BR6116-10, K3

MV1FZ & MV1FZS

  • Work: KM62256CLG-7, RAM1 & RAM2
  • Backup: KM62256CLG-7, RAM3 & RAM4
  • Video: KM62256CLG-7, RAM5 & RAM6
  • fast Video: CXK5814P-35L, RAM7 &RAM8
  • Palette: XLJ6265AF-10SL, RAM9 & RAM10
  • Sound: BR6216B-10LL, RAM11

MV2FS

  • Work: LH52B256N-70LL, D3 & D4
  • Backup: LH52B256N-70LL, G1 & G2
  • Video: LH52B256N-70LL, C7 & C8
  • fast Video: CXK5814P-35L, C9 & D9
  • Palette: CXK5864BSP-10L, B8 & B8
  • Sound: BR6216B-10LL, K11

MV2-01

  • Work: LH52B256N-70LL, E5 & E6
  • Backup: LH52B256N-70LL, H3 & H4
  • Video: LH52B256N-70LL, F13 & G13
  • fast Video: CXK5814P-35L, F12 & G12
  • Palette: CXK5864BSP-10L, B9 & C9
  • Sound: BR6216B-10LL, BR6216A-10LL, K13

MV-4F

  • Work: CXK58256MM-12L, G9 & H9
  • Backup: CXK58256MM-12L, D9 & E9
  • Video: CXK58256MM-12L, K9 & L9
  • fast Video: CXK5814P-35L, L11 & M11
  • Palette: CXK5864BSP-10L, F4 & H4
  • Sound: BR6216B-10LL, L1

MV-6

  • Work: H9 (lower) & J9 (upper)
  • Backup: E9 (upper) & F9 (lower)
  • Video: L9 & K9
  • fast Video: CXK5814P-35L, M11 & N11
  • Palette: CXK5864BSP-10L, G4 & H4
  • Sound: BR6116-100, M1
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