trunk/src/emu/sound/s14001a.c
| r21857 | r21858 | |
|---|
| 53 | 53 | _| |_ |
| 54 | 54 | ROM CLOCK/CKR <- |_|4 37|_| <- ROM D6 |
| 55 | 55 | _| |_ |
| 56 | | ?DAC TEST? ?? |_|5 36|_| -> ROM A10 |
| 56 | DIGITAL OUT 0 <- |_|5 36|_| -> ROM A10 |
| 57 | 57 | _| |_ |
| 58 | | ?DAC TEST? ?? |_|6 35|_| -> ROM A9 |
| 58 | DIGITAL OUT 1 <- |_|6 35|_| -> ROM A9 |
| 59 | 59 | _| |_ |
| 60 | | ?DAC TEST? ?? |_|7 34|_| <- ROM D5 |
| 60 | DIGITAL OUT 2 <- |_|7 34|_| <- ROM D5 |
| 61 | 61 | _| |_ |
| 62 | | ?DAC TEST? ?? |_|8 33|_| -> ROM A8 |
| 62 | DIGITAL OUT 3 <- |_|8 33|_| -> ROM A8 |
| 63 | 63 | _| |_ |
| 64 | 64 | ROM /EN <- |_|9 32|_| <- ROM D4 |
| 65 | 65 | _| S |_ |
| r21857 | r21858 | |
|---|
| 102 | 102 | an advertisement in the John Cater book probably also has this feature, in addition |
| 103 | 103 | to external speech rom banking. |
| 104 | 104 | |
| 105 | The Digital out pins supply a copy of the 4-bit waveform which also goes to the |
| 106 | internal DAC. They are only valid every other clock cycle. It is possible that |
| 107 | on 'invalid' cycles they act as a 4 bit input to drive the dac. |
| 108 | |
| 105 | 109 | Because it requires -10V to operate, the chip manufacturing process must be PMOS. |
| 106 | 110 | |
| 107 | 111 | /-----------\ |