Williams System 6

Matrix conversion

src/wpc/s6.c MACHINE_DRIVER_START(s6) imports PinMAME and installs no switch or lamp converter of its own, so System 6 inherits PinMAME's sequential core_swSeq2m/core_m2swSeq (src/wpc/core.c). Public switches are therefore sequential matrix positions addressed column-major, not column-times-ten notation:

Column 1 is public 1-8 and column 8 is public 57-64. The ROM strobes one column at a time through PIA 1 port B (s6_swcol_w) and reads the eight rows back through port A (s6_swrow_r).

Column 1 and the diagnostic column

Column 1 (public 1-8) is an ordinary matrix column that happens to carry the cabinet switches. When PinMAME's own keyboard handling is enabled, SWITCH_UPDATE(s6) overwrites it every frame from the S6_COMPORTS port (src/wpc/s6.h): tilt 1, ball-roll tilt 2, start 3, coin 1-3 4-6, slam tilt 7, high-score reset 8. With keyboard handling off, as under LibPinMAME and VPinMAME, the consumer writes these addresses directly.

The five negative addresses are internal matrix column 0 through the same n+7 formula and come from the upper byte of the same port:

They are service controls in the coin door or on the boards, never playfield positions.

Flipper buttons

System 6 flippers are not CPU-driven: the cabinet buttons switch the coils directly and the ROM only enables them. PinMAME still keeps its generic flipper column at internal column 11, which the sequential converter publishes at 81-88; CORE_SWLRFLIPBUTBIT is public 82 and CORE_SWLLFLIPBUTBIT is public 84 (src/wpc/core.h). core_updateSw copies those two bits into the matrix addresses a game names with FLIP_SWNO(left,right), and a zero argument means no copy. It also fabricates the synthetic flipper outputs 45-48 from them whenever the game-on enable is set (see the solenoid group). No System 6 driver declares FLIP_SOL or an FLIP_EOS bit, so the end-of-stroke positions 81, 83, 85 and 87 and the upper-flipper buttons 86 and 88 carry nothing.

Polarity

Every System 6 INITGAMEFULL in src/wpc/s6games.c aggregate-initializes the per-game wpc struct as {{0}}, so the per-game inverted-switch mask is zero and PinMAME normalizes nothing. The public level is the raw closed-equals-1 level of the switch.

Addressing

MDRV_DIPS(8+16) declares twenty-four DIP bits. A public DIP address is bank * 8 + bit + 1, where bank is the PinmameSetDIP bank and bit the bit within that bank's byte (core_getDip, src/wpc/core.c).

Bank 0 bits 2-7 are not declared.

How the ROM reads the CPU-board banks

s6_dips_r returns a four-bit nibble selected by the low two bits of the display strobe position, and only while Master Command Enter (-3) is held; the value is inverted because the ROM expects on=0. Strobe positions 0-1 return the low and high nibble of bank 1 and positions 2-3 the low and high nibble of bank 2. The source comment s6 games only want dipcol 2 records that the System 6 ROMs sample only the low nibble of bank 2 (D1-D4). Which physical switch and function each bit carries is game documentation; a definition must cite its own manual rather than this profile.

Address map

Addresses 49-50 belong to PinMAME's built-in simulator (sim_getSol), which no System 6 driver populates, and no System 6 driver declares hw.getSol for the custom range.

Special solenoids 17-22

The six special solenoids are driven from the CA2/CB2 lines of the four PIAs (s6_specsol1_w to s6_specsol6_w) and gated by the game-on enable. setSSSol indexes CORE_FIRSTSSSOL + n directly, so special solenoid n is public 16 + n with no permutation, unlike System 11 and Data East. Each is also published when the switch named in the game's sxx.ssSw[n-1] closes while the enable is set (s6_vblank), which models the hardware in which that playfield switch fires the coil itself. sxx.ssSw is per-game data from the fourth to ninth INITGAMEFULL arguments in src/wpc/s6games.c, and a zero entry means the slot is not switch-driven.

Synthetic flipper outputs 45-48

No System 6 driver declares FLIP_SOL, so core_updateSw fabricates flipper state in coreGlobals.solenoids2 from the synthetic flipper buttons at switch 82 (right) and 84 (left) whenever the game-on enable is set. 45/46 follow the right button and 47/48 the left. There is no driver-board output behind any of them: the physical flipper coils are switched by the cabinet buttons through the flipper relay.

Matrix addressing

PIA 2 port B selects lamp columns and port A drives the rows active-low: s6_lampcol_w stores the column byte as written, and s6_lamprow_w stores the row byte inverted (~data). core_setLamp places column bit c at lampMatrix[c], and the public lamp number read back through vp_getLamp is lamp2m(n) - 8 = n - 1. So public lamp = (column - 1) * 8 + row, with column 1 at 1-8 and column 8 at 57-64. System 6 declares no auxiliary lamp columns.

General illumination

System 6 has no general-illumination controller channel. coreGlobals.gi[] is written only by WPC, Whitestar and SAM drivers, and s6.c never touches it. System 6 games feed their general illumination from an unswitched transformer winding.