Sega Gremlin Color X
Contents
1. 741502 741532 741532 1127 7099 8 0504 7415125 10275 SHT 5 10276 B INPUT SHT 5 SHT 5 Uo TO HTS WAIT 14 741504 DE 7 2 05 a 4 7 8 13 4718 Ro gs aia 45 IZ di 7415374 u 5 5 5 re IN 914 2 15 e 191211698 10 71309 02 3 D R2 IZ R3 914 6 2K u gt GRN IN 914 13 741509 5 741532 1 2 R4 12 RI B 6 2K IZK 741509 gt BLU lt 3 741510 2 2 co 5 QTY CODE PART OR NOMENCLATURE BE REQD IDENT IDENTIFYING NO OR DESCRIPTION PARTS LIST NO UN ENSIONS ARE IN INCHES Gremlin Industries Inc TOLERANCES ARE San Diego California 91123 FRACTIONS DECIMALS ANGLES APPROVALS A 86 PIN CONNECTOR MATERIAL X Y Control Board 4 PIN MOLEX 24 PIN SOCKET 21 800 3155 100 0054 50 ON SIZE CODE IDENT NO DRAWING NO 800 0163 APPLICATION DO NOT SCALE DRAWING scare ONE 39 8 7 6 5 4 3 2 1 0 REVISIONS TE APPROVED RELEASED SD 14 20 5 ARON c x gt lt MF ky L D gt Te FL s 3 10 e 2 7 18 7 RI R3 i 3 9K ADSGI CD7 I 52. EEE vid to tok OF Fj ede 5 2 W e e x 22K R110 4 R10 R109 M NE100 ES gt 1908 in Ns X Le 8 m 5 Y C703 A R724 R725 Balsas Ke bo 1 12pf ra un gt 19VLUP22 x 4 t i fg 10706 N To P ZI me si 3 ue LE ND Pol 8 0 z KIE ll Qe Qux 6 cn yk R a kg gt I R116 01 50V 1 gt Me 5 gt 1K5 em wie P B LEVEL S ees T R700 8701 wit vo Bi a m T w M 2K2 2K2 EN 15K CES R410 Er e Ko Gm m D ye 1K C600 C702 010 au w R411 aw BRIGHTNESS RED P100 2 2pf Spf 710 38 R30 33 R138 NE 102 2M7 GND 16 3 100R NEY 1BOR q NE 2H C131 C410 9 R131 a I R412 man s Bi 9 a D 99 1 CENT R136 C UN D409 EE B LEVEL le 114003 er FH
3. 27 7 37 8 7 6 5 4 3 2 1 Fs E E RELEASED ps KD gt a e klej ce 4 C ANY mw 13 135 gt 2114 11 zna 12 zna 12 zna u30 uz gi UZB D e 30 ERE SEE HA 760 ela EE EH I5 ll 5 oon 8 SEZZHERBED E pb 11 111111 BEBESBEHEND 04 nana ZEL me BOG D L re j LIL e ERIS s 2 HHH a S 4 as qe q 7415245 5 IN 5 5 9 5 TO HE HAE HE 2 4 0 E 07 SE ERN CY MERE RAM Z RAM 2 RAM 2114 SE 2114 Zne 2114 isbu 1 u ues GSM EM wp xe 12 1 15 EE cog 8 Es D EE m GE ED el r mee SA B ugs a meem ime 5111 Ry E ARMA 351 12 35135 SF Y ES e 1 1 A JE
4. ASS GS EOE fc 0901 DEFLECTION AMP PCB ASS Y 02 170005 01 SEMICONDUCTORS SYMBOL IC600 D400 D401 D402 D403 D404 0405 0406 0407 0408 0410 0601 0602 0603 0604 0605 0701 0702 0703 0704 0705 2 0400 20401 20402 0400 0401 0600 0601 0602 0603 0604 0701 0702 0703 0704 CAPACITORS C400 C401 C402 C403 C404 C405 C406 C410 C411 C601 C620 C621 C622 C624 C701 C720 C721 C722 C724 RESISTORS R400 R401 R402 R403 R404 R405 R406 R410 R411 R412 R600 R601 R604 R605 R606 R607 29 DESCRIPTION Input Amplifier IC Rectifier 6A 200V Rectifier 6A 200V Rectifier GA 200V Rectifier GA 200V Rectifier 1A 200V Rectifier 1A 200V Rectifier 1A 200V Rectifier 1A 200V Diode T IN914 Rectifier IN4003 Diode TI IN914 Diode IN914 Diode T IN914 Diode IN914 Diode TI IN914 Diode IN914 Diode TI IN914 Diode TI IN914 Diode TI IN914 Diode TI IN914 Zener Diode IN5263B 5W 56V Zener Diode IN5239B 5W 9 1V Zener Diode IN5239B 5W 9 1V Transistor TIB 29B Transistor 18 298 Transistor MPSU60 Transistor 300V 5A Transistor MPS U10 Transistor MPS U10 Transistor 300V 54 MPSU60 Transistor 300V 5A MPSU60 Transistor MPS U10 Transistor MPS U10 Transistor 300V MPSUGO Capacitor 150NF 10 400V Capacitor 1000uF 80V Capacitor 680uF 160V Capacitor 6800uF 80V Capacitor 6800uF 80V Capacitor 10uF 25V Capacitor 10uF 25V Capacitor 100NF 20
5. DWG NO 800 0163 Ref Des C23 C14 1 13 C15 C22 XP1 U40 U9 U32 U42 U39 U20 U21 U35 U36 U48 U49 4 U37 U18 U41 U46 U2 U13 U10 U12 U34 U52 U14 U33 053 03 Ue U7 U44 U45 U1 US 024 031 U8 3 RI R3 R5 R7 R8 R2 R4 R6 01 06 X Y Control Board 800 0163 723 ME EM L jra Hs 1 89 528 32 Schematics 34 G 80 X Y BOARDS G 80 ADDRESS PCC PCR ADD INPUT G 80 BUS PROGRAM COUNTER OUT ADDRESS VIDEO RAM 4K X 8 MULTIPLEXER LATCH VECTOR ADDRESS COUNTER FETCH BLOCK DIAGRAM CURRENT TO VOLTAGE CONVERTER gt U DATA BUS SYMBOL ANGLE G 80 DATA BUS RATE 44 15 MULTIPLIER VECTOR ANGLE VCL gt CLOCK U m Ge D A 22 RATE DIVIDER COLOR WAIT U8 MULTIPLIER DRAW BOS ES END U22 VECTOR DRAW LENGTH 225 COUNTER CURRENT TO VOLTAGE 052 VCL CONVERTER LAST SYMBOL gt CHARACTER 011 DATA BIT 7 U52 LAST VECTOR U21 0 14 ADD TIMING GENERATOR Do CHARACTER DATA BIT O 35 Note You will find two color X Y monitor schematics printed in this manual The schematic of monitor G08 001 reflects the monitor currently being used in the games Model G08 003 schematic is for future reference
6. U1 U4 U28 U30 U40 U27 U14 054 057 U58 013 021 025 026 042 U43 2 029 035 038 015 020 05 010 053 048 049 055 6 031 034 041 051 044 047 011 022 024 050 012 039 R2 R4 8 RI 5 6 C29 0 4 5 X Y Timing Board 800 0161 818 88 83 HR 8 BEHABE 1 9 ma 30 Parts List Item Gremlin Part 1 150 0088 2 151 0002 3 151 0058 4 170 0219 5 212 0101 6 213 0001 7 280 0330 8 314 0018 9 314 0019 10 314 0040 11 314 0055 12 314 0058 13 314 0059 14 314 0060 15 314 0062 16 314 0067 17 314 0068 18 314 0074 19 314 0075 20 314 0078 21 314 0087 2 314 0093 23 314 0097 24 314 0099 25 314 0101 26 314 0108 27 314 0127 28 314 0128 29 314 0137 30 315 0046 31 315 0072 32 471 0123 33 471 0472 34 471 0622 35 481 0006 X Y Control Board Assembly Description CAP E 10 uf 25v CAP CER 100pf 50V CER 01 uf 16 V PC BOARD CONN 4 PIN M RTA SKT 24 PIN DUAL INLN CARD EJECTOR IC 74LS00 IC 74LS04 IC 74LS125 IC 745244 IC 74LS08 IC 74LS10 IC 74LS20 IC 741574 741 530 741 532 741 5191 741 5393 741 502 741 5139 7415374 7415161 7415245 7419285 741 5107 7419164 741 595 741 509 2114 251 514 RES 12K OHM YW 5 RES 4 7K OHM YW 5 RES 6 2K OHM 2 5 DIODE IN914 IN4148 31
7. 7415283 741500 2 u30 a p 74 SEE RES er YCL C jJ i ll e O e 4 B gt OE m as 4 7 i LL msn 8 5 a D UY lt D UX o 437 7 2 E rusos O j 00 k QTY CODE PART OR NOMENCLATURE REOD IDENT IDENTIFYING NO OR DESCRIPTION a UNLESS OTHERWISE SPECIFIED CONTRACT NO DIMENSIONS IN INCHES Gremlin Industries Inc TOLERANCES ARE mans FRACTIONS DECIMALS ANGLES San Diego California x is APPROVALS REN RAWN he e UE X Y Timing Board aa EA AI 8 Hai 888 CODE IDENT NO DRAWING NO REV BOO 5 800 0161 usenon senne 8 7 6 5 4 3 2 1 41 42 15 4 RAE 4 508 7415107 6 4 8 5 9 4 3 az PERE U4 741 510 721 745 3m e LS08 T aaa a Ng bj ue ES TRE 5 3 5 BER 74157 S04 EEE 8 5 3 U24 UM 34 74LS16 14 Bea BRAAS AAN 41345 931415 Jajaja 74LSI07 3 a He 2 B GA a A gt 5 y 13 u30 5 8 502 9 53 sng 8 x o gt NS 042 741574 45 Be 2 un GPW 2 a paz uli LS107 043 574 3 2 1
8. How um PNE APPROVED gt X Y Timing Board go 0 DRAWN A son CHECKED ee y p S e FINISH SIZE CODE IDENT NO DRAWING NO 800 3 55 700 0051 D 800 0161 USED ON APPLICATION DO NOT SCALE DRAWING SCALE NONE JSHeT 7 OF A RELEASED SD 14 20 81 A ARON 1508 741508 D 6 3 2 2 22 lt u gt PCR 49 1507 z u BI 1504 713 40 0 3 4 6 YE 4 jum gt gt gt EDGINT gt u30 504 VCL E dus I 3 m FETCH 21 SCL DRAW 3 DRAW 2 145 lt 12 13 WIZ 24 VCE 18 MUX 8 gt PCC lt LS02 3 5 5 5 wd Q eq EET FEBRE REQD IDENT IDENTIFYING NO OR DESCRIPTION UNLESS OTHERWISE SPECIFIED CONTRACT NO DIMENSIONS ARE IN INCHES Gremlin industries Inc T I FRACTIONS DECIMALS ANGLES San Diego California 92123 XX gt A XXX GLOSSARY A0 A15 Address Bus 0 15 A0 A15 are the 16 lines of the CPU s address bus ADD Add 10 ADD causes the Program Counter to jump ahead 10 addresses in video memory for the start of the next group of Symbol Instructions Analog Signal A type of signal that represents all possible voltage levels between two predetermined levels Blank Turn off the electron beam BOS Beam Off Screen BOS when low blanks the
9. R624 R625 D E C302 e 9 i 1x8 1808 1 8000 TU a tcm 7 10601 Em es con ge 3 I 100 1 ple 87 36 1514 12 16 lt REIS i 1010 08 2741 1 2155 01 R62 I 2155 8623 0601 100R d R940 l 1N914 1062 3308 R400 0602 2W 42 60 01 SIV 5 IK C912 5 2 TN914 U 5 E 002u 50V 022 u MYLAR lt Ju C904 sz R923 R930 9 O 19401 IK 916 2247 R942 2708 688 3 1 R404 298 9 1V 150K 50V 5 6 S 226R f me low LS 77 5 2405 0408 20401 829 7 253906 100R E 1 2 0902 Mes v lt CARO U60 Se E E 342 0602 7 R924 19903 41 342 02 1 IMPSU10 R300 QW 470R 2N3904 i 89227 A 000 22K w DE 8351 I R630 1N914 l c BOR 487 1 ae m COMMON 22K D604 8631 E 0 ME A fav 10 gt p BIB 55 y 2 11 C404 Tv 9 1v SA 8 150 1 i 68000 5406 14914 i 270K ARK PE 6808 4 R310 R936 j 6W Be 10K 93 R935 R937 63 Y AMP 4M7 R308 T 1 0 0 0 0 0 3 L
10. at the color X Y monitor cir cuits and see where this deflection coil current comes from For the follow ing explanation refer to the X Y monitor schematic in this manual circuitry in block A accepts two varying voltage levels one for Vertical one for Horizontal from the G 80 boards These voltages are called ANALOG signals because they represent all voltage levels between two pre determined levels Let s say that we want an analog signal that can vary between two voltages 3 and 3 volts We could control it to look something like this on an oscilloscope As the signal changes it moves through all possible voltage levels that exist between 3 and 3 volts Don t confuse this type of signal with a digital one The digital signal switches between 0 and typically 5 volts It does not drop to a negative voltage level As these varying voltages come into the X Y monitor Block A they activate the X and Y power amplifiers shown in schematic Blocks B and F respectively These amplifiers control the amount of current that flows into the X and Y deflection coils depending on the voltage levels on the inputs Remember this current controls the electron beam movement so if we vary the input voltage we vary the output cur rent AND the direction of the beam The following chart will clarify this INPUT VOLTAGE BEAM Y AMP POSITIVE UP Vertical NEGATIVE DOWN X AMP POSITIVE RIGHT Horizontal NEGATIVE
11. beam whenever the beam moves off the four sides of the screen Cathode A piece of metal in the neck of a CRT that when charged with a voltage emits electrons for the beam CDO CD7 Character Data Bits 0 7 CDO CD7 represent the 8 data lines from video memory 00 07 Data Bits 0 7 00 07 represent the 8 data lines of the microprocessor s data bus DCL Draw Clock DCL is generated from DRAW and VCL it clocks the Vector Length counters down Deflection Amplifier One of two power amplifiers in the X Y monitor that generate deflection current for the deflecton coils Deflection Coil One of two coils surrounding the neck of CRT that create a magnetic field to deflect the beam horizontally or vertically Deflection Current The current through either deflection coil that is proportional to the amount of beam deflection Digital Signal A type of signal that switches between 0 volts and typically 5 volts only Digital to Analog Converter D A A circuit or IC that converts a particular digital word into one voltage level DRAW DRAW is generated by the Timing Board and is used to cause the beam to unblank D UX D UY Down Up X Y D UX Y tells the Up Down counters on the Timing Board to count either up or down Electron Beam A stream of electrons shaped into a thin ray that when intensified lights up the point it strikes on the inside surface of the CRT There is one beam in a black white monitor and three beams in a color monitor END E
12. can be moved in any direction depending on how it is deflected X Up Down Counter The Up Down Counters on the Timing Board that contain the digital value of the beam position on the X axis Y Axis The Imaginary line that describes the vertical movement of the beam 44 YCL Y Clock YCL clocks the Y position Up Down counters with pulses that represent the horizontal line length and angle Y Up Down Counter The Up Down Counters on the Timing Board that contain the digital value of the beam position on the Y axis 1 14 These signals are sequentially produced by the Timing Generator to latch the Symbol and Line Instructions from video memory into specific locations on the Timing and Control Boards 45 46 Notes
13. is the electron beam inside its CRT Unlike the beam in the raster scan unit the X Y beam can be moved in any direction we want All we have to do is figure out where we want to move it and then move it It s like being able to move the light beam from a high intensity advertising beacon all over the sky from one position on the ground Of course it s not quite as carefree as that because we must tame the beam to behave as we want We need to tell the beam when to turn on or intensify to draw the design we want how big to make the design what color the lines should be what angles the lines will take and when to stop drawing More about this later For now remember that we are directly influencing the X Y beam to create our lines by moving it and turning it on when necessary in the raster scan all we had to do was turn on the beam at the right times Important differences between the raster and X Y monitors are that the X Y s have no need for vertical or horizontal oscillators and drive circuits since these pre determine the electron beam s movement Also no flyback pulse is needed in the X Y to move the beam to the top of the raster However a very high voltage is still necessary in the X Y to attract the electron beam to the front surface of the tube Before we delve into the circuits that make up the color X Y monitor let s consider how we actually control an electron beam Inside the picture tube neck there is a piece of
14. just once It loads the character words into memory During an actual game however it does more than act as a loader Whenever we want to move our symbols on the screen for example rotate the triangle we need some way of changing all those words to represent new lines and angles Well the CPU fulfills this job perfectly Under program control the CPU is told when and how to alter these words to create a whole range of dynamic displays different colored lines new angles longer or shorter lines bigger or smaller characters whatever the game play calls for Also the microprocessor governs all game functions such as player control and coin inputs or sound and speech outputs The CPU then gives us the variety and color in the X Y games 13 G 8O CONTROL AND TIMING BOARDS OPERATION DETAILED Note Designations in parentheses will be used throughout this discussion to refer the reader to the proper schematics C X Y Control Board 800 0163 sheets 5 and 6 T X Y Timing Board 800 0161 sheets 5 6 and 7 e g C6 Control Board sheet 6 The CPU addresses video memory U24 U31 through multiplexer ICs U48 U49 C5 Character words are taken from memory as the Program Counter ICs U33 U34 U22 C5 addresses them through multiplexers U36 U49 U35 and U21 C5 If Word 1 Symbol Instructions says to not display a symbol the Program Counter is advanced 10 counts by U33 a full adder which adds 10 to the cou
15. metal called a CATHODE When it is charged with a In both the color X Y and color raster monitors there are actually three electron beams one for each of the three colors red green and blue For now it s easier to think of just one electron beam More on the color beams later The Color X Y Monitor Circuits voltage it generates electrons As the electrons are emitted they are shaped to form a thin ray or beam that strikes the front of the monitor The only way the beam will move up or down left or right is if a magnetic field is ap plied around the beam This is what the DEFLECTION COILS located around the CRT neck do There are two coils one to move the beam up or down VERTICAL DEFLECTION COIL and one to move it left or right HORIZONTAL DEFLECTON COIL So by running some current through either coil we create a magnetic field around the beam to deflect it in any direction The larger the current we put through either coil the stronger the magnetic field and the more the beam will deflect While we re on the subject of beam movement consider why this monitor is called an X Y monitor Picture our symbol on the screen again the horizontal line is called the X axis and the vertical line is the Y axis hence X Y monitor So make a mental note that when we move the beam horizontally we are moving it on the X axis moving the beam vertically oc curs on the Y axis Okay now let s look closer
16. on the X axis WORDS 4 AND 5 These tell the boards where the beam is on the Y axis The last four words then give the exact coordinates of the electron beam WORDS 6 AND 7 Words 6 and 7 tell the X Y hardware what the First address is of the Line Instructions section WORDS 8 AND 9 These tell the hardware how the complete symbol our triangle will appear on the screen or at what angle WORD 10 This word tells what the overall size of the design will be 10 G 80 Control And Timing Boards Operation Again since we re only making one design there will be no more 10 word groups after the one above Now take a look at the Line Instructions section of memory GROUP 1 WORD 1 This word tells the G 80 boards either to blank or to unblank the line And it informs the boards that either additional 4 word groups follow or no more groups follow Finally it defines the color this par ticular line is to be WORD 2 This word represents the length of the line the beam is to draw WORD 3 Word 3 tells the hardware at what angle the beam should make its line 45 degree 90 degree WORD 4 Word 4 defines in which of the four sections of the screen the line is to appear which quadrant The remaining 4 word groups contain the same representations of their respective lines as in Group 1 The values will be different of course depen ding on how the lines differ In our triangle example we would find 3 more groups of four words
17. 05 Q706 MO1 MISCELLANEOUS DYO1 1100 3101 X DESCRIPTION Power Transistor Power Transistor Power Transistor Power Transistor Motor Blower Fan Pix Tube Deflection Yoke Degaussing Coil Pix Tube PCB Socket Yoke Wedge Parts List tem Gremlin Part 1 151 0005 2 151 0058 3 170 0218 4 211 0008 5 212 0101 6 213 0001 7 213 0004 8 213 0010 9 230 0009 10 280 0330 11 313 0004 12 313 0044 13 314 0018 14 314 0019 15 314 0040 16 314 0046 17 314 0055 18 314 0058 19 314 0062 20 314 0070 21 314 0073 22 314 0074 23 314 0076 24 314 0078 25 314 0093 26 314 0097 27 314 0101 28 314 0108 29 314 0120 30 314 0135 31 315 0019 32 471 0202 33 471 0331 34 471 0392 35 475 0024 36 151 0008 37 150 0088 Timing Board Assembly Description CAP CER 680pf 50v CAP 01 uf 16v AX PC BOARD CONN PIN TEST PT CONN 4 PIN RTA SKT 24 DUAL INLN SKT 16 PIN DUAL INLN SKT 8 PIN DUAL INLN XTAL 15 46848 CARD EJECTOR IC LM 741 EN DIP IC AD561 IC 74LS00 IC 74LS04 IC 74LS125 IC 74S04 IC 74LS244 IC 74LS08 IC 74LS74 IC 74LS86 IC 74LS175 IC 74LS191 IC 74LS157 IC 74LS02 IC 74LS374 74LS161 IC 74LS283 IC 74LS107 IC 74LS154 IC 74LS11 IC 2708 RES 2K OHM YW 5 RES 330 OHM ZW 5 RES 3 9K OHM YW 5 POT 1K 10 TURN CAP 001 uf 50V CAP E 10 uf 25 RDL 29 DWG 800 0161 Ref Des C7 C1 C3 C6 C8 C28 1 XP1 XU39 XU1 XU4 XU2 XU3 Y1 U2 U3
18. 0V Capacitor 22uF 250V Capacitor luF 50V Capacitor 100pF 10 500V Ceramic Capacitor 1uF 50V Capacitor 47pF 1096 500V Capacitor 068 200V Capacitor 1uF 50V Capacitor 100pF 10 500V Ceramic Capacitor Capacitor 47pF 10 500V Capacitor 068uF 200V Thermistor 120V 60R 33R 4W 10 WW 22K 1W 10 2K2 25W 5 220R 10W 8K2 5W 5 680R 6W 4K7 25W 5 2M7 25W 5 1M 25W 5 470R 25W 596 910R 25W 5 30K 25W 5 50K Trim Pot 100K 25W 596 2K4 25W 596 COMPONENT LAYOUT C X Y P OM PONEN LAYOUT 26 DEFLECTION AMP PCB ASS Y CONT D RESISTORS CONT D SYMBOL R608 R610 R611 R612 R621 R622 R623 R624 R625 R626 R627 R628 R629 R630 R631 R632 R633 R634 R635 R700 R701 R702 R703 R704 R705 R706 R710 R711 R712 R714 R715 R721 R722 R723 R724 R725 R726 R727 R728 R729 R730 R731 R732 R733 R735 R930 R931 FUSES F400 F401 F600 F 700 DESCRIPTION 15 25W 5 AK7 25W 5 1 Trim Pot 4K7 25W 5 6K2 25W 5 180R 25W 5 22K 25W 5 1K8 25W 5 180R 25W 5 100R 25W 5 18K 5W 5 270R 25W 5 100R 25W 5 22K 5W 5 180R 25W 5 470R 2W 5 150R 25W 5 82R 25W 5 1 5 10W 2K2 25W 5 2 2 25W 5 5K Trim Pot 15K 25W 5 22K 25W 5 22K 25W 5 15K 25W 5 2K4 25W 5 100K 25W 5 50K Trim Pot 1K5 25W 5 1K 25W 5 5K6 25W 5 180R 25W 5 22K 25W 5 1K8 25W 5 180R 25W 5 1008 25W 5 18K 5W 5 270R 25W 5 100R 25W 5 22K 5W 5 180
19. 5 NExT assy 741504 SEALE 8 7 6 5 4 3 2 777 N 15 MHz lt gt 137 TPIT DT A 22 vi o 14 100 Pf 2 04 3 DI 02 Ree SHT SSG SZACIE ES 7 gt A m SE A _ j 1 3 07 18641219 171513 1 7415244 i 154 BER 2 3 15117 5 4 3 2 1 22 22 22 REVISIONS RELEASED SD 4 20 81 A ARON MULTIPLY CLOCK 17 D 0 132 au De 032 741504 4 6 z epla HH AO BR 741504 MU 3 7415107 E u53 74LSiol u52 5 0 251514 On 2 I 8 TO SHT 5 L B 15 CD 7 CD7 CD J lt 741595 2 10 7ars a j 2 eas ee 3 9 34 2 5 4 5 5 10 gt AAA 31 741545 2 0 741544 S E REI BIE uz 51 9 ut Um 879 I 5 74 2 SAUER 5 Pus 5 14 5 744 518 17 q i 1504 WA Y 7 8 3 u3 74140 du 10 gt 2 us pe Baur 3 741574 3 2 1594 4 5 NOTES 6
20. 741502 3 C8 C26 D UY ZEZBEBER 14 BOS YEL T M 5 14 C 2B iit q 12 RS AGE 3 9K IK u4 SO 12 7455191 2 458 12 2 0 6 3 7 mg T REQD IDENT IDENTIFYING NO OR DESCRIPTION HERW SPECIFIED CONTRACT NO DIMENSIONS ARE IN INCHES Gremlin Industries Ine TOLERANCES ARE San Diego California 92123 DECIMALS ANGLES A DRAWN SON DUONG 3 12 81 DRAWA SON DUONG lt gt PIN CONNECTOR 5 82 X Y Timing Board Ek Re 1 4 PN A SM ho E d FINISH GH SIZE CODE IDENT NO DRAWING NO REV 24 PN SOCKET 800 3155 700 0054 0 800 0161 NOTES Assy USEDON APPLICATION NOT SCALE DRAWING 40 800 Ol6l C 8 7 6 5 MORS AS B EE MN are ay DI RELEASED SD 4 20 81 3 EKON HH MER 8 gt 347 ala Je 3 u5e 055 444 VEC SYM lt 7415 374 448 7415374 ea uso 2 Eli 5 Hr E th HI T ix li e 2315 73 3 5 7 9 312 Ihre sjela 2 415 7415244 7415244 D uae U47 g u27 4 7 U44 045 7 4 7415283 C4 14 11 x 7415283
21. B 2 I Z EKZZ Gi MIE WEF ae eee eee SHT 6 NB 8 EEEE wur p HEE Mr El 741500 Jen qu e Es Mux 18 WAIT 3 c See x M gt lt gt pee BE BRE SB SSS z 1 11 gt AAA AA AO Hu PEB gt er ENE Sae a E E a s IH e I H SERRA E 1 LL JHE BE 1s ishehelizfa 5 Seel 043 ei 5 oe Es 68 lt 020 0 uz B INPUT a 14 2141 8 1 113115 17 MENU SEREM _ 4102 19 171513 EE a 5 5 lt lt 21 SCL uz lt 04 037 2141627 24 13 10 PCC Zn 741508 QTY CODE PART OR NOMENCLATURE PCR UD REQD IDENT IDENTIFYING NO OR DESCRIPTION le DIMENSIONS ARE IN INCHES Gremlin Industries Inc TOLERANCES ARE 7415 FRACTIONS DECIMALS ANGLES ANE San Diego Cabforn a A lez 7 515 4 5 6 MATERIAL en je nf pew X Y Control Board _ 2 15 nd A 23 ux ERR j C4 24119 FINISH a ET ODE IDENT NO DRAWING NO REV 800 3133 100 0054 p 800 0163 A 0 si
22. LEFT Earlier we said there has to be a way to turn on intensify the electron beam to create an image on the screen Well there are three more inputs to the color X Y that allow us to do just that They are the inputs labelled RED GREEN and BLUE on the schematic and they accept signals from the G 80 hardware These color signals activate the three color electron beams through the circuit in schematic Block C Keep in mind that because these signals are analog we can vary them to increase or decrease the intensi ty of the color beams and therefore vary the color on the screen For exam ple turning all three signals full on produces a white display Using what we know so far let s apply it to an actual example of drawing something simple on the screen a white line for instance Point the center of the screen is the starting point for the electron beam To move the beam to point B we have to supply voltages to the monitor s inputs that cause the beam to move at a 45 degree angle To do that reguires two increasing positive voltages on the horizontal and vertical inputs See the chart above Not only are these voltages positive in this case they also have to be equal And if they are equal the deflection coils will force the beam the same distance upward and the same distance to the right AT THE SAME TIME Moving at any other angle is just a matter of making one coil deflect more or less than the other But n
23. LESS OTHERWISE SPECIFIED 10705 I e RESISTANCE CARBON 193300 6100 esos 8105 0 1 1 RESIST 00 K 1 FOR PURPOSES AND CONTINUING f AR 12pf RELIABILITY 4 Um 2K5 N i vol REPLACE ALL COMPONENTS MARKED 10701 GAIN BLE VEL 19 VLUP22 WITH SAFETY SYMBOL WITH IDENTICAL IMPSU60 1 1 I TYPE 10706 1MJ15004 Exp BR gt Ar Wels mm use o9 1 1 i 1 1P100 6 BLUE 8 n T GREEN BRIGHTNESS py 180R T NE 2H li can C131 f R412 250V ie Pu e 1 2 L I 1 R136 ARS x D409 B LEVEL 144003 s s s O 1 R905 68A TW R902 12K b 24R A 47K Yaw N sul cas A 1 126V 1 5 1 5KV 4 1N400 609 re 108 4 160 1W
24. ND goes low to signify that the line has been drawn FETCH FETCH enables the various multiplexers on the Control Board and latches data from video RAM Flyback Transformer A transformer that produces high voltage for the X Y CRT In raster scan systems this device also generates the flyback pulse to move the beam to the top of the screen Line Instructions The upper portion of video memory that contains groups of 4 line words Each group of four represents one line of the symbol to be drawn 43 MEMR Memory Read is generated from the CPU Board to take data out of video RAM MEMW Memory Write MEMW is generated from the CPU Board to store data video Multiplexer A circuit or IC that accepts outputs from a number of devices but passes the outputs from only one device at a time MUX Multiplexer MUX is combined with FETCH to control the enabling of multiplexers on the Control Board PCC Program Counter Clock PCC is generated from SCL and it advances the Program Counter PCR Program Counter Reset PCR resets the Program Counter to the address of the first Symbol nstruction in RAM Its frequency is 40 HZ Program Counter On the G 80 Timing Board the Program Counter is the circuit that addresses video memory to release the Symbol Instruc tions Raster The pattern of horizontal lines created by the electron beam s movement on the inside surface of the picture tube CRT Raster Scan Monitor A black white or col
25. OFF Check the transistors in the color drive circuits for shorts or opens when one or more colors is missing in the picture and the G 80 boards are known to be good 18 G 80 Boards Color X Y Monitor Color X Y Monitor Input Specifications ADJUSTMENTS On the X Y Timing Board there are two pots that adjust the outputs of the X R3 and Y R6 current to voltage converters U2 and U3 On the monitor there are a number of factory set adjustments Do not use these controls They are R702 WIDTH R920 R611 HEIGHT R106 GAIN R917 R117 GAIN R918 The following controls can be used to adjust the monitor if necessary R605 vert and R712 horiz Center picture on the screen R107 red R118 green Adjust color of picture R136 blue R930 Adjusts brightness of picture R922 Focuses picture Vertical Input 3 V max Horizontal Input 4 V max Red Input Full Brightness 4 V Green Input Full Brightness 4 V Blue Input Full Brightness 4 V 19 20 Paris Catalog 22 MONITOR REPLACEMENT PARTS LIST Note Call SEGA Gremlin Customer Service for availability of these parts and for part numbers EHT SUPPLY ASS Y G08 001 02 170003 01 SEMICONDUCTORS SYMBOL DESCRIPTION 1 900 EHT Control Circuit ZD900 200V Zener Diode ZD901 200V Zener Diode 0900 Rectifier TA 1400V D901 Rectifier 1A 1400V Q901 Transistor TIS93 Q902 Transistor TIS92 TRANSFORMERS T900 Horiz Buffer Tran
26. R 25W 5 390H 2W 5 150R 25W 596 1R5 10W 2M Trim Pot 1M1W 10 5A Slow Blow 5A Slow Blow 4A Slow Blow 4A 125V Slow Blow CRT SOCKET PCB ASS Y 02 170006 01 SEMICONDUCTORS SYMBOL Q100 0101 0102 0103 0104 0105 LAMPS NE100 NE101 NE102 NE103 27 DESCRIPTION Transistor MPS u10 Transistor MPS u10 Transistor MPS u10 Transistor MPS 1 0 Transistor MPS u10 Transistor MPS u10 Lamp Lamp Lamp Lamp CRT SOCKET PCB ASS Y CONT D CAPACITORS SYMBOL C100 C101 C102 C110 C111 C112 C113 C130 C131 RESISTORS R101 R102 R103 R104 R105 R 106 R107 R108 R109 R110 R112 R113 R114 R115 R116 R117 R118 R119 R120 R121 R122 R123 R124 R130 R131 R132 R133 R134 R136 R137 R138 R139 DESCRIPTION Ceramic Capacitor 100pF Capacitor 10NF 10 500V Capacitor 10NF 10 500V Ceramic Capacitor 100pF Capacitor 1ONF 10 500V Ceramic Capacitor 10NF 1KV Ceramic Capacitor 1ONF 1KV Ceramic Capacitor 100pF Capacitor 10NF 10 500V 1008 25W 5 2K7 25W 5 3K3 1W 5 4708 25W 5 1K6 25W 5 250R Trim Pot 2 5 Trim Pot 22K 5W 596 180K 25W 596 1K 25W 5 100R 25W 5 2 7 25W 5 3K3 1W 5 470R 25W 5 1K6 25W 5 250R Trim Pot 2K5 Trim Pot 22K 5W 5 1808 25W 5 1K 25W 5 220K 5W 5 1K 5W 5 470K 5W 5 100R 25W 5 2K7 25W 5 1W 5 620R 25W 5 1K6 25W 5 2K5 Trim Pot 22K 5W 5 180R 25W 5 1K 25W 5 HEAT SINK ASS Y 02 170004 01 SYMBOL Q605 Q606 Q7
27. V to flyback EHT oscillator A degaussing circuit is provided through D404 D405 and R400 The CRT is automatically degaussed when R400 is cooled sufficiently to conduct cur rent through the degaussing coil Digital Analog Conversion THE G 80 s ROLE It s not hard to imagine how fast the input signals to the color X Y monitor must be changing in order to produce fantastic X Y game displays It s also not hard to understand that a computer must be making all this happen That is exactly the case with the G 80 hardware used in the color X Y games It contains two new boards X Y TIMING and CONTROL that produce the X Y monitor input signals The G 80 still relies on its CPU EPROM SOUND and SPEECH boards to complete the computer But what does a digital computer have to do with producing the analog signals required by the X Y monitor Basically the computer converts cer tain digital signals into analog ones On the G 80 X Y boards are circuits some are actually ICs called Digital To Analog converters D A for short These circuits accept a particular digital word that is a string of 0 and 5 voltage levels The D A converter senses the word and outputs one and only one voltage level which corresponds to the digital word For example we could design a simple D A converter that would generate the following voltages when we input certain digital words DIGITAL WORD ANALOG OUTPUT 0000 1 VOLT 1111 1 VOLT 1000 0 VOLT This is
28. a very basic case but it shows that for a particular D A converter we always produce one voltage level from the corresponding digital input If we cycle through a variety of digital inputs we ll get a variety of output voltages If we do this fast enough we actually create a rapidly varying range of output voltages This output is exactly the kind of signal we need to drive the deflection coils in the monitor Now we know where the analog signals come from What about the digital ones What is their role in the X Y system Here s what happens Before we can display anything on our X Y screen we have to ask some questions Answers are provided for example s sake QUESTIONS ANSWERS FOR EXAMPLE 1 What do you want on the A triangle screen 2 How many Just one 3 What kind of design What A triangle with 3 equal sides or angles will it have one with 3 60 degree angles 4 What size or how long are the Make each side about 3 long lines in it 5 Where do you want it on the The center of the triangle should screen be the center of the screen 6 What colors do you want 2 sides white one blue 7 How will it be positioned on Like this the screen BLUE 8 What will it do once its on the Just sit there screen 9 How many lines does the In our triangle the beam must electron beam have to make make 4 lines to create the design C A even though we won t see it B C and D Now that we have all ou
29. after Group 1 By now you may be wondering what all these words really are Since we are dealing with a digital computer the words we described above must be digital More accurately they are digital values of the specifications re quired to create our designs We have taken the specifications for sizes angles shapes colors and locations and converted them into digital words that the G 80 system understands Then we let the G 80 read these words and create displays that the words represent Before we go any further you should know that the words read from the video RAM didn t get there by magic The microprocessor put them there All the words that represent all the characters and designs in a game are kept safely in on the EPROM Board When the game is powered up the CPU moves the various word groups from EPROM to RAM Once situated in video memory the words are made available to the Timing and Control boards to create displays Briefly here is what the two X Y boards do with the words Refer to the Block Diagram to locate the circuits discussed After all the character words are loaded into video RAM the Program Counter is forced to call on the first RAM address Here the Program Counter finds the first word in the Symbol Instructions section One at time these ten words are taken out of RAM and latched into specific parts of the X Y boards This sequence is controlled by the Timing Generator which generate
30. e KRN e kk k k k xn e e K L R734 C603 12pf LX EGER ER Eze m i P eh m m im im dm te kk fe de k k k he R610 R611 4K7 1K HEIGHT kk dd eun C914 C915 15 1 5n 15KV 1 5KV 0406 D407 C402 144003 1N4003 680u 100V R930 R929 390K 390K VW 28900 200V NT om z lt x X X X X X X 16 15 14 13 Caras IC 14 2155 1 ms Fee t 2K2 1 10 3KV BEAM por P400 x E 5 RESEN REE JE LEHE C916 1 Ou 10u NC MA a X de p EL te te te A Ah ee AAA Model Number GO8 OOI Qa G X Y MONITOR m ja s s x x s s s s gt gt w s gt IK NE 100 TIC NOTES i i TUE NE 2H UN
31. ect DC voltages from the power supp ly Also make sure the 3 VAC reset signal is being applied to the CPU board If all these tests prove normal then eliminate the power supply as cause of the problem and proceed to check the remaining game components G 80 boards and monitor NOTE Schematics for CPU EPROM SOUND and SPEECH Boards are in the Game Manual In most cases a simple test will help to isolate a problem of no picture to either the G 80 boards or the monitor On an oscilloscope look for varying voltage signals on pins 1 and 4 of the 4 pin Molex connector on the Timing Board If the signals look similiar to those shown in Figure 1 check for signals swinging between 0 and 4 volts on the R G B outputs 4 pin Molex connector pins 4 1 2 respectively on the Control Board If all three outputs are at 0 volts suspect the X Y boards If the signals appear normal suspect the monitor as the cause of the problem If however pin 1 to the monitor s Horizontal Input is held at or near 4 or 4 volts DC suspect one or both X Y boards If pin 4 to Vertical Input is held at or near 3 or 3 volts suspect the G 80 boards In either case TURN OFF THE POWER AND IM MEDIATELY DISCONNECT THE X Y MONITOR Proceed to check the 17 Color X Y Monitor inputs to D A converters U1 and U4 5 for active signals Verify that none of the Character Data lines CD0 CD7 are pulled high or low or are floating Check for the XCL and YCL clock si
32. en U18 s output goes low it signifies that no more symbols are to be drawn Then the Program Counter is reset by the 40 HZ signal to the start of the video memory to repeat the display sequence U22 T7 is the DRAW latch and its output through U21 creates the DRAW signal which initiates a sequence that causes the beam to draw This sequence occurs on the Timing Board sheet 6 By this time all video words have been stored in their proper places in the system On the Timing Board T7 the vector angle is in 056 the symbol angle in U55 So when DRAW goes high it causes strings of digital pulses that represent the vector and symbol angles 14 to be generated These streams of pulses from U28 T6 are the ones that clock the X and Y Up Down counters shown on T5 U15 U20 U25 16 tells the counters in which direction to count up or down D UX D UY Then the outputs of the Up Down counters X and Y become the digital words that are converted to analog signals by D A converters U1 and U4 5 Op Amps U2 and U3 T5 convert current from the D A converters to voltage levels These levels drive the Vertical and Horizontal inputs to the monitor Signals DRAW and VCL are combined in U28 T6 to form DCL Draw Clock This signal clocks down the Vector Length counters U15 U16 and U17 C6 which contain words that represent various lengths of the lines to be displayed When the counters have counted down to 0 the END signal becomes acti
33. gnals from U28 T6 Verify that the 15 MHZ crystal clock is operating and that a 40HZ signal is present on pin 11 of U13 T7 Check BOS signal to be sure it is not held low signal DRAW should be switching high and low On the Control Board observe the signal FETCH to ensure it pulses high and low Also none of the Data lines 20 07 should be held high or low or floating C5 Check for clock signals PCC and SCL C5 Look for input changes on U1 and U5 of the color circuit C6 also pin 3 of U4 should be active high and low Figure 1 When the X Y monitor is suspected with a problem check for all correct power supply voltages as shown in the schematic Isolate incorrect voltages to either the monitor power supply or to the circuit receiving the voltage NOTE The color X Y monitor contains a circuit that shuts off the high voltage oscillator when no vertical or horizontal inputs are present DO NOT ATTEMPT TO RAISE OR LOWER EITHER INPUT WHEN TESTING THE MONITOR DOING SO WOULD CREATE EXCESSIVE DEFLECTION CURRENT THAT COULD SEVERELY DAMAGE THE MONITOR For testing the monitor use only the outputs of the G 80 hard ware In addition DO NOT operate the monitor WITHOUT proper fuses in the main AC line If a monitor is causing the main fuse to blow proceed to check the deflection amplifiers power transistors Q605 Q606 Q705 and 2706 WITH THE POWER OFF Also check for a shorted transistor or diode in the deflection amplifiers POWER
34. ing a more technical explanation One more thing Be sure to read the manual before attempting any repairs or adjustments to your games Now read on SEGA Gremlin Technical Publications Department Table of Contents Introducing The Color X Y Monitor 1 ColorX YMonitorBlockDiagram 6 ColorX YTheory Detailed 7 CER e ee e TOM dE dq iras 9 G 80BoardsTheory Detailed 14 Troubleshooting and Adjustments 17 E 43 Raster Scan Verus X Y Monitor Raster Scan Displlay gt INTRODUCING THE COLOR X Y MONITOR To introduce the workings of the color X Y monitor let s first pay tribute to the other kind of monitor the raster scan You may remember from your knowledge of raster scan displays like those in a TV that the electron beam inside the tube always moves in a predictable way That is it always starts at the top left of the screen and scans across it forming a pattern of horizontal lines on the inside surface of the tube as it moves downward When it gets to the bottom the beam is forced back to its starting point and repeats the raster scan movement To create a simple display for example a large symbol on the raster scan monitor we figure out first where we want it to appear on the screen let s say the center in this case Then we gene
35. lection amps can swing between 60V and 60V This voltage is high enough to provide up to 8 amps peak to peak of current through the deflection coils Color drive circuits are located in schematic block C and they accept a 4 volt maximum signal on the RGB inputs The outputs drive the three electron beams in the CRT Three neon glow bulbs NE 100 101 and 102 act as spark arrestors for the color drive outputs to the CRT In block D the CRT is shown as well as the brightness adjustment for it The circuit of D409 R412 R411 R410 is a spot killer that prevents the electron beams from burning a hole in the phosphor surface of the CRT when the monitor is turned off Section G of the schematic consists of the high voltage oscillator in IC 14 2155 01 which operates the HV transformer T901 This transformer is technically a flyback type but it is not used to deflect the beam The IC serves two other functions It senses the presence of the 10 3KV through R921 and R932 and compares it against the 9 1 supply voltage to ensure a regulated output Also this circuit senses the presence of varying current in either deflection coil If no change is detected the IC shuts down the high voltage oscillator to prevent the beam from burning the front of the CRT Finally the X Y power supply is shown in block E it generates the follow ing voltages 60V to X Y power amplifiers 55V to RGB video drivers and spot killer 9 1V to ICs 120
36. n The circuitry in schematic block serves two purposes First it compensates for a type of distortion known as pin cushion distortion This occurs because the electron beam must travel a greater distance when strik ing the edges of the CRT than when it hits the center If we cause the beam to trace along the edges of the CRT the beam would draw a box with its left and right sides bowed inward To compensate for the effect this circuit off sets the point where the beam would normally strike the CRT surface Secondly this circuit contains two error amplifiers one for the horizontal and one for the vertical inputs Each error amp has two inputs one is set to zero volts the other accepts the analog signal from the G 80 and senses cur rent movement in the deflecton coil The analog signal is allowed to pass through the error amps and drive the deflection power amps The deflec tion amps are shown in blocks B and F The outputs of the X and Y power amps pass current through their respective deflection coils Now the output leads of the two coils are connected back to the analog inputs of the respec tive error amps as mentioned above This acts as an error or feedback signal and ensures that the current through the deflection coil remains pro portional to the voltage on the error amp inputs If this signal were not pro vided there would be a slight deflection error when an analog input signal was present The outputs of the X and Y def
37. nter when signal ADD goes low The Vector Ad dress counter is composed of U10 U11 and U12 C5 and is ioaded with the first address of the Line Instructions from video memory s Character Data Bus CDO CD7 The CPU s Data Bus 00 07 is brought to the memory through a bi directional buffer U14 C5 The signal labelled FETCH C5 latches the various Character Data words from memory The MUX C5 signal commands the multiplexer ICs to allow either the CPU Program Counter or Vector Address counter to address memory MEMR memory read and MEMW memory write come from the CPU board to read from or write to the RAM Signal VCE C5 Vector Clock Enable increments the Vector Address counter PCC Program Counter Clock is the string of pulses that advances the Program Counter PCR Program Counter Reset ensures that the Program Counter starts counting at the first location in video RAM each time PCR goes low This signal occurs first at power up and then 40 times a second during program execution So it causes the X Y monitor to draw and re draw each symbol on the screen 40 times a second The signal is generated from the master clock crystal Y1 and U14 T7 by U31 U34 and U22 T7 The other clock signals VCE PCC FETCH ADD MUX and VCL are all generated by the X Y timing board T7 The outputs of the Last Symbol and Last Vector latches U52 T7 are AND d together with the signal END which originates from the Control Board s U18 C Wh
38. o these qualities The circuitry acts as a digital ruler and protractor and measures any line in terms of how many pulses in length and angle it is All this figuring is formed by the Full Adder s 2708 EPROM and Rate Multipliers The output of each Rate Multiplier XCL and YCL is a string of clock pulses that clock the respective Up Down counter X or Y But the pulses are not just random pulses They are the digital equivalents of a line with a particular length and angle So we clock both Up Down counters at the same time with these meaningful pulses Doing so we force the counters to start counting from the beam position words previously stored in the counters The important point is this If we change the digital values of the beam position words we change the position of the beam through the D A converters How far and at what gt 12 The CPU s Role angle we change the beam depends on the amount of pulses applied to the Up Down counters Just before the beam is moved the color of the line black included is sent to the monitor through the RGB D A converters There you have it one line For more lines the G 80 system rapidly follows the same procedure of reading the symbol and line words latching them calculating line values color values and then forcing the beam line by line to form complete symbols Notice that throughout our discussion we have mentioned the microprocessor s role
39. or monitor in which the electron beam always moves in a predetermined way forming a pattern of raster lines on the screen SCL Sequence Clock SCL is used to clock the Timing Generator and it clocks the Vector Address Counter Symbol Instructions The lower portion of Video memory that contains groups of 10 symbol words Each group of 10 represents one complete symbol to be drawn on the screen Timing Generator On the G 80 Timing Board the Timing Generator produces a sequence of 15 signals that latch the words from video memory into various parts of the X Y boards Unblank Turn on the electron beam VCE Vector Count Enable VCE enables the Vector Address Counter so that it may count VCL Vector Generator Clock VCL is used on the Control Board in computing the length of a line to be drawn Its frequency is 2 5 MHZ Vector Address Counter On the G 80 Control Board the Vector Address Counter addresses video memory to release the Line nstruc tions Vector Length Counter On the G 80 Control Board the Vector Length Counter is loaded with the length of the line to be drawn WAIT WAIT periodically stops the PCU so other circuits can gain access to video memory X Axis The imaginary line that describes the horizontal movement of the beam on the screen XCL X Clock XCL clocks the X position Up Down counters with pulses that represent the vertical line length and angle X Y Monitor A black white or color monitor in which the electron beam
40. ote that both coils force the beam AT THE SAME TIME Since we don t want this 45 degree line to show up on the screen we don t feed any voltages to the RGB inputs But we know the beam is at point B awaiting further deflection Now we cause the voltage on the horizontal X input to go negative and leave the vertical voltage where it is Also we turn on the RGB inputs to give us a white line From the chart you can see that these voltages will cause the beam to move to the left horizontally to point C Now we have our line Here is what our input signals looked like during this process V Horizontal X x Voltage KA V V Vertical Y Voltage In our example we made a very short line considering we could have drawn one clear across the screen In order to draw longer lines in any direc tion we simply increase the positive or negative voltage on the inputs Remember the higher the voltage the more the deflection the longer the line The remaining circuits in the monitor are a power source block E the CRT and brightness adjustment block D and the high voltage generator block G Here is a block diagram of a basic X Y color monitor COLOR X Y MONITOR BLOCK DIAGRAM DEFLECTION COILS YOKE CRT HV 22 5kv VERTICAL FAIL HORIZONTAL 4v THE COLOR X Y MONITOR CIRCUITS DETAILED Refer to the schematic for the following discussion of the monitor s operatio
41. r causes the Line Instruction words to be moved out of memory one at a time Here is what happens to the group of four words 1 Word 1 is stored in the Color Latch and U52 Last Vector 2 Word 2 is stored in the Vector Length counters Word 3 is loaded into the Vector Angle circuit Word 4 is used in the Vector Angle circuit Up to this point then 10 words that describe some symbol and 4 words that represent one line in that symbol have been clocked out of memory When the Vector Address counter takes out the last group of words that represents the last line to be drawn memory access is switched back to the Program Counter It will now either restart the sequence as before if there is another symbol to be drawn or it will stop until the counter is reset to the beginning again Now the system is ready to draw its first line to actually move the beam because we have given it exact specifications to do so The position of the electron beam is now known Words 2 through 5 in the Symbol Instruc tions so we know where the beam will start to draw Then the X Y boards _ calculate the length and angle of our first line And they know the color if any of this line In our triangle remember our first line A is the one we don t actually see but it must be drawn We also know that it must be drawn at a O degree angle straight up The boards calculate the line length and angle by assigning a certain number of digital clock pulses t
42. r specifications we have to store this information someplace so the Timing and Control boards can get to it and understand it That place is video memory See the Block Diagram It holds 4096 8 bit words or bytes Of course we don t stick all this into video memory and hope the X Y boards f ind it We store the information in an orderly fashion First we divide the video memory into two main groups et s call them 1 The Symbol Instructions and 2 The Line Instructions Into the Symbol In structions section we store one group o ten words or every symbol or design we put on the screen In our example we have only one symbol so we use only 10 words Into the Line Instructions section we put one group of four words for every Line that the beam has to draw So for our triangle which reguires 4 lines we would store 4 groups of 4 words in the Line In structions space Every word we store in memory has one and only one ad dress so the same word can be called on over and over Now let s look closer at the Symbol Instructions memory space Here is what the 10 words do Don t be concerned with actual values of those words right now WORD 1 It tells the X Y boards either to make the beam draw the symbol in this group of words or not draw it And the same word informs the boards that either this group of words is the only group or that there are more 10 word groups to follow WORDS 2 AND 3 These tell the boards where the beam is
43. rate a video signal that represents the plug the signal into the monitor and presto we get a a raster scan display What we have done is intensify the electron beam so that only those points corresponding to the light up on the raster Here s how it would look close up Nice Line an See anything unusual Notice how the vertical line is not much of a line but more a column of stacked s This occurs because the raster lines which run horizontally inside the CRT are spaced slightly as the beam traces them So what we see looking at our line from top to bottom is a tiny segment of the lit up raster then a black space another lit up segment another black space on and on Now the horizontal line of our is perfect It s one solid lit up line because there are no spaces in the raster in this direction The X Y Electron Beam Controlling The Electron Beam Well the fact that you can t get high quality lines in both directions has never really bothered anyone until the X Y monitor a completely dif ferent type of display If we created a centered on an X Y monitor it would look like this X Y monitor Nice Lines We would see two perfect solid lines no gaps anywhere How does this happen The reason is that there is NO RASTER in the X Y monitor none at all What creates the high quality solid lines in any direction in an X Y monitor
44. s T901 Horiz Output Trans COILS L900 Horiz Delay Choke L901 Flyback Load Coil L902 RF Choke 27UH CAPACITORS C900 Electrolytic 4U7 16V C901 Electrolytic 4U7 16V C902 Capacitor 22uF 50V C903 Ceramic Capacitor IN5 50V C904 Electrolytic 22uF 16V C905 Electrolytic 22uF 16V C906 Ceramic Capacitor C907 Capacitor 47N 100V C908 Capacitor 47NF 400V C911 Electrolytic 100uF 16V C912 Capacitor 100NF 100V C914 High Current Capacitor C915 High Current Capacitor C916 Capacitor 10uF 250V C917 Capacitor 10NF 1000V C918 Capacitor 47NF 100V C919 Electrolytic 470 uF 16V C920 Capacitor 2N2 3K V C921 Capacitor 22uF 50V RESISTORS R900 10K 25W 5 R901 10K 25W 5 R902 47K 25W 5 R903 47K 25W 5 R904 150K 25W 5 R905 12K 25W 5 R906 10K 25W 5 R907 4K7 25W 5 R908 470K 5W 5 R909 470K 5W 5 R910 470K 5W 5 R911 2K7 25W 5 R914 6208 25W 5 R915 10K 25W 5 R916 150K 25W 5 R917 200R Control R918 2K Control R920 20K Control R921 HV Safety Res 200M 10 R923 270R 25W 5 R924 470R 25W 5 R927 33R 25W 5 R928 390K 5W 5 R929 390K 5W 5 R930 68R 25W 5 R931 100K 25W 5 R932 180K 25W 5 EHT SUPPLY ASS Y KIT 05 170004 01 Q900 PWR Transistor 5 1400V R922 Focus Control 23 PORE Rn n E LAYOUT ME HAE O d RA 24 E
45. s 15 active low signals only one signal pulses low at a time to latch the words Next the following sequences occurs 1 Word 1 15 latched into U52 Last Symbol block 2 Words 2 and 3 from the Symbol Instructions are loaded into the X axis Up Down counters 11 Drawing The Line Words 4 and 5 are loaded into the Y axis Up Down counters Words 6 and 7 are stored in the Vector Address counter Words 8 and 9 are stored in the Symbol Angle latch Word 10 is loaded into the Serial Multiplier Now the first 10 words of a character we wish to display are stored somewhere If we had not wanted to draw this character the Program Counter would have jumped to the next set of 10 symbol words if there were another symbol Once the Program Counter is finished moving out the words the Vector Address counter takes control of memory This switching between the Program and Vector Address counters is governed by the Multiplexer Through it the G 80 Address Bus or one or the other counter can address video memory Only one device is allowed access to memory at a time When it is the Vector Address counter s turn to get into memory the counter addresses the first word of the Line Instructions section The reason for this is that the Vector counter was previously loaded with words 6 and 7 in the Symbol Instructions section These words tell the Vector Address counter the locations of the first word in the Line Instructions section Now the Vector counte
46. seca Cremlin Color X Y Monitor E 5 t E Service Manual No 420 0605 Color X Y Monitor Service Manual SEGA Cremlin 8401 Aero Drive San Diego CA 92123 Color X Y MONITOR SERVICE MANUAL Copyright 1981 by SEGA Gremline All Rights Reserved PREFACE With the introduction of its new color X Y game SEGA Gremlin is changing the look of video games in the 80 s The new color X Y technology is at once the most innovative outlet for game con cepts that before existed only in the minds of the designers However this new technology creates an immediate need for an understanding of how it works and how to keep it working That is the reason for this manual The manual describes the operation of the color X Y monitor as well as the two new G 80 boards TIMING and CONTROL that control the monitor In addition a maintenance section is provided as is a complete color X Y monitor parts catalog Reference is made in this manual to the four other G 80 boards SPEECH CPU EPROM SOUND but com plete schematics parts lists and descriptions for these boards can be found in the game manual Also provided in the manual is a glossary of color X Y terms The copy in the manual is printed in light and bold face type This is done to direct the reader to all light face print for a basic understanding of the X Y system material printed in bold face takes the reader deeper into the subject matter by offer
47. to the Game Manual Troubleshooting section Essentially any repair procedure consists of isolating a problem first to one or two major game components the monitor for example From there we eliminate more possibilities by isolating one or two faulty circuits then eliminate to the faulty component level In the Color X Y system we are dealing with 3 major game components 1 The Power Supply 2 The G 80 Set of Boards 3 The Color X Y Monitor So in a typical maintenance procedure we would first attempt to determine which of the 3 major elements is defective In the following sections we will look at each element and some of its sub divisions as a guide in isolating blems NOTE Power Supply schematics are in the Game Manual Usually the power supply can be eliminated as the source of a problem if the game comes up on the screen The major exception is when the game plays normally but no game sounds are produced In this case the power supply s amplifier circuit should be checked for audio signals from the sound and speech boards If they are present on the amplifier output then a bad speaker or connection is probably the cause of the problem If the signals are not there suspect the amplifier circuits on the sound and or speech boards If the picture does not appear on the screen check the power supply for the main AC voltage to the primary of its transformer then ensure that the G 80 boards are supplied with the corr
48. ve As the X and Y Up Down counters are clocked their out puts are sensed by U5 U10 T5 which are multiplexers The multiplexers are necessary to tell the system when the beam is off the screen It does this by generating the BOS signal T5 Then BOS is AND d with DRAW at US C6 to blank turn off the beam whenever BOS goes low U3 C6 compensates for the inherent delay in deflecting the electron beams It provides a number of taps to select a range of delay times From U2 C the color word is read and applied to the RGB D A converters U5 U1 and associated diodes and resistors The RGB outputs go directly to the color X Y monitor U50 7415154 T7 decoder IC selects one of 15 outputs by making the output low The outputs sequentially store the video memory words one at a time in various parts of the X Y boards Only one output is allowed to go low at a time U50 is enabled at pin 18 forty times per second by U22 T7 and at pin 19 021 U51 sequences U50 through its 15 count cycle at count 14 pin 16 of U50 goes low to initiate the DRAW signal through U40 U21 and U22 T7 The circuitry at the top of schematic C6 U45 U51 U54 is not used in generating and displaying characters on the X Y monitor Its function is to perform lengthy calculations under software control 15 16 Introduction Power Supply G 80 Boards TROUBLESHOOTING AND ADJUSTMENTS NOTE For instructions on the built in SELF TEST refer
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