Car RamRod Bringing Pinball Into the Future! Brian Arment, Ryan Hunter, Aaron Shoaf
Williams ® Touchdown Originally Produced November of 1967 Electromechanical Solenoid and relay driven No solid-state devices Not in working order
Original Internals Relays and solenoids controlling game play Relays and solenoids controlling scoring
Inspiration Newer machines use solid state devices such as those in the more modern machine at right. We will not be mimicking the design but will use the same basic idea in modernizing our old machine.
Overview User Input Micro-controller Driver Board Playfield A/V Controller Display Power Supply 6 Vac 5 V DC 25 Vac
User Input Two Flipper Buttons Start Coin or Manual Operation MC 14043 Quad SR Latch – De-bouncing RFLFSB MC 14043 CR 4 line bus to MCU
Micro-Controller MC68HC11 Handles interrupts for input from sensors on playfield and users. Controls light patterns, scoring, A/V state, game play options, game play state Handles control of driver board for fail-safe solenoid operation.
Driver Board Provides Necessary current and voltage for devices like: Solenoids (flippers, pop-bumpers, kickers) Lamps (in playfield and lightbox) Nearly everything on the playboard uses it It is controlled directly by the MPU via logic level voltages
Driver Board Needs and Complications: Needs to step up from 3.3-5v DC to 6 or 24v rectified AC Make sure the flipper transistors used can handle up to 8 amps each Need to control around 15-20 different lamp circuits The pop-bumpers and kickout solenoids each need up to 3 amps.
Driver Board Larger BJTs (3-8 amps) for the coils Smaller BJTs (300 mA) for the lamps Pull up resistors and latches Logic-level input from MPU To SolenoidsTo Lamps 6/24V AC
Playfield (visible) A few stipulations for the upper playfield: Want to keep the functionality as close to the original game as possible Want it to play a bit faster than the original (incline needs to be steeper) Possibly implement larger flippers Need to replace all rubber, lights Need to touch up paint and polish the board
Playfield (underneath) A few stipulations for the lower playfield: All the displayed electromechanical relays are replaced by solid state via the fore-mentioned driver board All aluminum wiring is removed and replaced with 18-20 gauge copper wiring All contact switches are cleaned
A/V Controller Contains two separate controllers: DAC: Has a file select input with data fed from the MPU Has internal storage of uncompressed WAVE or PCM files. DVC: Reads the current score and points from data register Writes to individual LED panels
A/V Controller Display Controller/Decoder -Probably an FPGA -Could also be a ROM -Can display customs graphics Current Score Score Display Points Display LED Bar Graph Audio Controller -Several sound bits stored in flash memory -A programmable ROM selects the correct track -D/A converter outputs RCA Play Select Speaker System
Display Since this is a restoration, try to keep the scoreboard looking the same: Replace analog score and point tumblers with individual dot-matrix digital displays Replace mechanical football wheel with LED bar graph Use analog lamps for ball in play section
Audio Two 4 inch car speakers Powered subwoofer Run off of A/V controller Speaker receives line level signal from A/V controller A/V Controller
Division of Labor Aaron: Driver Board, Power Supply, MPU, Display, A/V controller, RAM Brian: MPU board, A/V controller, Flash Memory, RAM, Line Bus (controllers), EPROM Ryan: MPU, EPROM, Flash Memory, RAM, Display, Driver Board, Power Supply All: Playfield - wiring, refurbishing, testing
Risks and Contingency Plan A/V controller: Implement set of beeps and bells for audio and toned down preprogrammed display art. Cosmetic restoration User Options 3 or 5 ball play #coins / credit Free play Multi-ball