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Extra Hard Mid Boss
Relating to the Playstation-to-Saturn pad converter topic, here's how to read the Nights pad using SH2 direct control:
The pad is what the SMPC manual calls a "3-wire handshake method peripheral". To determine if the controller is of this type, use the following algorithm:
In 3-wire mode, the TH bit acts as an attention or chip select line, TR acts as a data toggle and TL acts as an acknowledge signal. The data is sent in the R, L, D and U bits, and is valid when TR == TL. To end the transaction, set both TH and TR to 1. In code:
According to the SMPC manual, the two first data values form the peripheral's Saturn ID sequence. Furthermore, at least for some peripherals it seems the first value may be the device ID and the second value the number of data bytes following the ID sequence. While this seems to be true for the Nights pad in both modes, at least the Saturn multitap does not seem to follow this format.
Here's the data sent by the Nights pad in "O" mode:
Here's the data in "+" mode:
For all button bits a zero means pressed. The analog trigger values range from 0 (min) to 0xFF (max). If the value goes above around 0x90 the digital button is registered as pressed. The digital button remains pressed until the analog value goes below around 0x56. The thumbstick axes range from 0 (left/up) to 0xFF (right/down) with 0x80 being neutral for both.
The pad is what the SMPC manual calls a "3-wire handshake method peripheral". To determine if the controller is of this type, use the following algorithm:
Code:
/* These initialization steps should always be performed. */
DDR1 = 0x60; /* Configure the TH and TR pins as outputs, the rest as inputs. */
IOSEL = 1; /* Configure port 1 for SH2 direct control. */
EXLE = 0; /* Disable the external latch. */
/* Read Megadrive ID. */
PDR1 = 0x60; /* TH = 1, TR = 1 */
/* wait 2 usec */
id1 = PDR1 & 0xF;
PDR1 = 0x20; /* TH = 0, TR = 1 */
/* wait 2 usec */
id2 = PDR1 & 0xF;
if (id1 == 1 && id2 == 1)
/* 3-wire peripheral */
else
/* Megadrive pad, Saturn digital pad or other device */In 3-wire mode, the TH bit acts as an attention or chip select line, TR acts as a data toggle and TL acts as an acknowledge signal. The data is sent in the R, L, D and U bits, and is valid when TR == TL. To end the transaction, set both TH and TR to 1. In code:
Code:
int toggle = 0;
for (ii = 0; ii < ndata; ii++)
{
PDR1 = (toggle << 5); /* TH = 0, TR = toggle */
while ((PDR1 & 0x10) >> 4 != toggle)
;
controldata[ii] = PDR1 & 0xF;
toggle = 1 - toggle;
}
PDR1 = 0x60; /* End transaction. */According to the SMPC manual, the two first data values form the peripheral's Saturn ID sequence. Furthermore, at least for some peripherals it seems the first value may be the device ID and the second value the number of data bytes following the ID sequence. While this seems to be true for the Nights pad in both modes, at least the Saturn multitap does not seem to follow this format.
Here's the data sent by the Nights pad in "O" mode:
Code:
R L D U
1: 0 0 0 1
2: 0 1 1 0
3: Right Left Down Up
4: Start A C B
5: R Trg X Y Z
6: L Trg 1 1 1
7: AX7 AX6 AX5 AX4
8: AX3 AX2 AX1 AX0
9: AY7 AY6 AY5 AY4
10: AY3 AY2 AY1 AY0
11: AR7 AR6 AR5 AR4
12: AR3 AR2 AR1 AR0
13: AL7 AL6 AL5 AL4
14: AL3 AL2 AL1 AL0Here's the data in "+" mode:
Code:
R L D U
1: 0 0 0 0
2: 0 0 1 0
3: Right Left Down Up
4: Start A C B
5: R Trg X Y Z
6: L Trg 1 1 1For all button bits a zero means pressed. The analog trigger values range from 0 (min) to 0xFF (max). If the value goes above around 0x90 the digital button is registered as pressed. The digital button remains pressed until the analog value goes below around 0x56. The thumbstick axes range from 0 (left/up) to 0xFF (right/down) with 0x80 being neutral for both.
