NEO-BUF: Difference between revisions

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==Replacement==
==Replacement==
[[File:Neo-buf_bypass.jpg|thumb|Picture from MVS-Scans]]
[[File:Neo-buf_bypass.jpg|thumb|Picture from MVS-Scans]]
On some MVS boards, some NEO-BUF chips are just used as buffers for the [[68k]] data bus. There are reports of succesful repairs done by replacing them with a small bypass board which simply connects the A side with the B side (see picture).
On the {{PCB|MV1A}} and {{PCB|MV1B}}, one NEO-BUF chip is used as a uni-directionnal buffer for the [[68k]] data bus. Some of these faulty chips were replaced by small passive pass-through boards by third parties, which may cause some games to crash:
 
* MV1B: GA1 on the SLOT1B board
Note that this should '''NOT''' be done to replace damaged NEO-BUF chips which are used for other purposes. This can only work for:
* MV1A: GA11
* GA1 on the SLOT1B board of the {{PCB|MV1B}}
* GA11 on the {{PCB|MV1A}}


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

Latest revision as of 03:37, 5 October 2023

Package QFP48
Manufacturer
First use 1994 ?
Used on MV1A MV1B NEO-CDM3-2_board

Dual 74HC245 octal transceivers in one chip. This chip is extensively used in CD systems to multiplex subsystem and 68k accesses to DRAMs.

Also found on late MVS boards.

Pinout


Edit this pinout

Replacement

Picture from MVS-Scans

On the MV1A and MV1B, one NEO-BUF chip is used as a uni-directionnal buffer for the 68k data bus. Some of these faulty chips were replaced by small passive pass-through boards by third parties, which may cause some games to crash:

  • MV1B: GA1 on the SLOT1B board
  • MV1A: GA11
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