furnace/doc/7-systems/msm6295.md

# OKI MSM6295

this chip is an upgrade from the MSM6258 in that it provides 4 ADPCM channels at a fixed output rate up to 32 KHz depending on clock rate. between the late '80s and late '90s, it was one of the most common, if not _the_ most common soundchip used in arcade machines: Capcom, Toaplan, Kaneko, Atari, Tecmo, the list can go on and on...

without bankswitching, the chip supports 256kB of sample RAM and can hold up to 127 samples at once.

## effects

- `20xx`: **set chip output rate.**
  - `0`: /132
  - `1`: /165

## info

this chip uses the [MSM6295](../4-instrument/msm6295.md) instrument editor.

when not bankswitched, maximum sample length is 522240 samples.

## chip clock rates

like MSM6258, MSM6295 is an extremely basic ADPCM sound codec. it has no variable sample rate; it depends on clock rate of the chip itself. the clock can be divided by either 132 or by 165 to get the sample rates listed below:

| clock rate         |     /132 |     /165 |
|--------------------|---------:|---------:|
| 0.875 MHz          |  6629 Hz |  5303 Hz |
| 0.89 MHz           |  6742 Hz |  5394 Hz |
| 0.9375 MHz         |  7102 Hz |  5682 Hz |
| 1 MHz              |  7576 Hz |  6061 Hz |
| 1.02 MHz           |  7727 Hz |  6182 Hz |
| 1.056 MHz          |  8000 Hz |  6400 Hz |
| 1.193 MHz (Atari)  |  9038 Hz |  7230 Hz |
| 1.5 MHz            | 11364 Hz |  9091 Hz |
| 1.79 MHz           | 13561 Hz | 10848 Hz |
| 2 MHz              | 15152 Hz | 12121 Hz |
| 2.112 MHz          | 16000 Hz | 12800 Hz |
| 3 MHz              | 22728 Hz | 18182 Hz |
| 3.58 MHz           | 27122 Hz | 21697 Hz |
| 4 MHz              | 30304 Hz | 24242 Hz |
| 4.224 MHz          | 32000 Hz | 25600 Hz |

## chip config

the following options are available in the Chip Manager window:

- **Clock rate**: sets the rate at which the chip will run.
- **Output rate**: sets the chip clock divider.
- **Bankswitched**: add an NMK112 chip to increase sample memory to 16MB and the maximum number of samples to 8192. each bank is up to 63KB with sample headers, and the maximum sample length is 129024 samples.