1 EESchema Schematic File Version 4 2 LIBS:AcornElectronMainboard-cache 3 EELAYER 26 0 4 EELAYER END 5 $Descr A4 11693 8268 6 encoding utf-8 7 Sheet 2 9 8 Title "" 9 Date "" 10 Rev "" 11 Comp "" 12 Comment1 "" 13 Comment2 "" 14 Comment3 "" 15 Comment4 "" 16 $EndDescr 17 $Comp 18 L Device:R R? 19 U 1 1 61DF6407 20 P 2000 2900 21 AR Path="/61DF6407" Ref="R?" Part="1" 22 AR Path="/61DF4BC2/61DF6407" Ref="R3" Part="1" 23 F 0 "R3" V 1793 2900 50 0000 C CNN 24 F 1 "330R" V 1884 2900 50 0000 C CNN 25 F 2 "" V 1930 2900 50 0001 C CNN 26 F 3 "~" H 2000 2900 50 0001 C CNN 27 1 2000 2900 28 0 1 1 0 29 $EndComp 30 $Comp 31 L Device:R R? 32 U 1 1 61DF640E 33 P 2900 2900 34 AR Path="/61DF640E" Ref="R?" Part="1" 35 AR Path="/61DF4BC2/61DF640E" Ref="R4" Part="1" 36 F 0 "R4" V 2693 2900 50 0000 C CNN 37 F 1 "330R" V 2784 2900 50 0000 C CNN 38 F 2 "" V 2830 2900 50 0001 C CNN 39 F 3 "~" H 2900 2900 50 0001 C CNN 40 1 2900 2900 41 0 1 1 0 42 $EndComp 43 $Comp 44 L Device:Crystal X? 45 U 1 1 61DF6415 46 P 2200 2600 47 AR Path="/61DF6415" Ref="X?" Part="1" 48 AR Path="/61DF4BC2/61DF6415" Ref="X2" Part="1" 49 F 0 "X2" H 2200 2868 50 0000 C CNN 50 F 1 "17.7345MHz" H 2200 2777 50 0000 C CNN 51 F 2 "" H 2200 2600 50 0001 C CNN 52 F 3 "~" H 2200 2600 50 0001 C CNN 53 1 2200 2600 54 1 0 0 -1 55 $EndComp 56 $Comp 57 L 74xx:74LS04 IC? 58 U 1 1 61DF641C 59 P 2000 3400 60 AR Path="/61DF641C" Ref="IC?" Part="1" 61 AR Path="/61DF4BC2/61DF641C" Ref="IC8" Part="1" 62 F 0 "IC8" H 2000 3717 50 0000 C CNN 63 F 1 "74LS04" H 2000 3626 50 0000 C CNN 64 F 2 "" H 2000 3400 50 0001 C CNN 65 F 3 "http://www.ti.com/lit/gpn/sn74LS04" H 2000 3400 50 0001 C CNN 66 1 2000 3400 67 1 0 0 -1 68 $EndComp 69 $Comp 70 L 74xx:74LS04 IC? 71 U 2 1 61DF6423 72 P 2900 3400 73 AR Path="/61DF6423" Ref="IC?" Part="2" 74 AR Path="/61DF4BC2/61DF6423" Ref="IC8" Part="2" 75 F 0 "IC8" H 2900 3717 50 0000 C CNN 76 F 1 "74LS04" H 2900 3626 50 0000 C CNN 77 F 2 "" H 2900 3400 50 0001 C CNN 78 F 3 "http://www.ti.com/lit/gpn/sn74LS04" H 2900 3400 50 0001 C CNN 79 2 2900 3400 80 1 0 0 -1 81 $EndComp 82 $Comp 83 L 74xx:74LS04 IC? 84 U 3 1 61DF642A 85 P 3500 3400 86 AR Path="/61DF642A" Ref="IC?" Part="3" 87 AR Path="/61DF4BC2/61DF642A" Ref="IC8" Part="3" 88 F 0 "IC8" H 3500 3717 50 0000 C CNN 89 F 1 "74LS04" H 3500 3626 50 0000 C CNN 90 F 2 "" H 3500 3400 50 0001 C CNN 91 F 3 "http://www.ti.com/lit/gpn/sn74LS04" H 3500 3400 50 0001 C CNN 92 3 3500 3400 93 1 0 0 -1 94 $EndComp 95 $Comp 96 L Device:C C? 97 U 1 1 61DF6431 98 P 2450 3400 99 AR Path="/61DF6431" Ref="C?" Part="1" 100 AR Path="/61DF4BC2/61DF6431" Ref="C5" Part="1" 101 F 0 "C5" V 2198 3400 50 0000 C CNN 102 F 1 "100pF" V 2289 3400 50 0000 C CNN 103 F 2 "" H 2488 3250 50 0001 C CNN 104 F 3 "~" H 2450 3400 50 0001 C CNN 105 1 2450 3400 106 0 1 1 0 107 $EndComp 108 $Comp 109 L Device:C C? 110 U 1 1 61DF6438 111 P 3500 2600 112 AR Path="/61DF6438" Ref="C?" Part="1" 113 AR Path="/61DF4BC2/61DF6438" Ref="C6" Part="1" 114 F 0 "C6" V 3248 2600 50 0000 C CNN 115 F 1 "33pF" V 3339 2600 50 0000 C CNN 116 F 2 "" H 3538 2450 50 0001 C CNN 117 F 3 "~" H 3500 2600 50 0001 C CNN 118 1 3500 2600 119 0 1 1 0 120 $EndComp 121 Wire Wire Line 122 1700 3400 1700 2900 123 Wire Wire Line 124 1700 2600 2050 2600 125 Wire Wire Line 126 1700 2900 1850 2900 127 Connection ~ 1700 2900 128 Wire Wire Line 129 1700 2900 1700 2600 130 Wire Wire Line 131 2300 3400 2300 2900 132 Wire Wire Line 133 2300 2900 2150 2900 134 Connection ~ 2300 3400 135 Wire Wire Line 136 2600 3400 2600 2900 137 Wire Wire Line 138 2600 2900 2750 2900 139 Connection ~ 2600 3400 140 Wire Wire Line 141 3050 2900 3200 2900 142 Wire Wire Line 143 3200 2900 3200 3400 144 Connection ~ 3200 3400 145 Wire Wire Line 146 3200 2900 3200 2600 147 Wire Wire Line 148 3200 2600 2850 2600 149 Connection ~ 3200 2900 150 Wire Wire Line 151 3200 2600 3350 2600 152 Connection ~ 3200 2600 153 Text GLabel 3750 2600 2 50 Input ~ 0 154 0V 155 Wire Wire Line 156 3750 2600 3650 2600 157 Wire Wire Line 158 3800 3400 3900 3400 159 Text GLabel 3900 3400 2 50 Output ~ 0 160 CLOCK_VIDEO 161 $Comp 162 L Device:R R? 163 U 1 1 61EEF884 164 P 2000 1300 165 AR Path="/61EEF884" Ref="R?" Part="1" 166 AR Path="/61DF4BC2/61EEF884" Ref="R1" Part="1" 167 F 0 "R1" V 1793 1300 50 0000 C CNN 168 F 1 "330R" V 1884 1300 50 0000 C CNN 169 F 2 "" V 1930 1300 50 0001 C CNN 170 F 3 "~" H 2000 1300 50 0001 C CNN 171 1 2000 1300 172 0 1 1 0 173 $EndComp 174 $Comp 175 L Device:R R? 176 U 1 1 61EEF88B 177 P 2900 1300 178 AR Path="/61EEF88B" Ref="R?" Part="1" 179 AR Path="/61DF4BC2/61EEF88B" Ref="R2" Part="1" 180 F 0 "R2" V 2693 1300 50 0000 C CNN 181 F 1 "330R" V 2784 1300 50 0000 C CNN 182 F 2 "" V 2830 1300 50 0001 C CNN 183 F 3 "~" H 2900 1300 50 0001 C CNN 184 1 2900 1300 185 0 1 1 0 186 $EndComp 187 $Comp 188 L Device:Crystal X? 189 U 1 1 61EEF892 190 P 2450 1000 191 AR Path="/61EEF892" Ref="X?" Part="1" 192 AR Path="/61DF4BC2/61EEF892" Ref="X1" Part="1" 193 F 0 "X1" H 2450 1268 50 0000 C CNN 194 F 1 "16MHz" H 2450 1177 50 0000 C CNN 195 F 2 "" H 2450 1000 50 0001 C CNN 196 F 3 "~" H 2450 1000 50 0001 C CNN 197 1 2450 1000 198 1 0 0 -1 199 $EndComp 200 $Comp 201 L 74xx:74LS04 IC? 202 U 6 1 61EEF899 203 P 2000 1800 204 AR Path="/61EEF899" Ref="IC?" Part="6" 205 AR Path="/61DF4BC2/61EEF899" Ref="IC8" Part="6" 206 F 0 "IC8" H 2000 2117 50 0000 C CNN 207 F 1 "74LS04" H 2000 2026 50 0000 C CNN 208 F 2 "" H 2000 1800 50 0001 C CNN 209 F 3 "http://www.ti.com/lit/gpn/sn74LS04" H 2000 1800 50 0001 C CNN 210 6 2000 1800 211 1 0 0 -1 212 $EndComp 213 $Comp 214 L 74xx:74LS04 IC? 215 U 5 1 61EEF8A0 216 P 2900 1800 217 AR Path="/61EEF8A0" Ref="IC?" Part="5" 218 AR Path="/61DF4BC2/61EEF8A0" Ref="IC8" Part="5" 219 F 0 "IC8" H 2900 2117 50 0000 C CNN 220 F 1 "74LS04" H 2900 2026 50 0000 C CNN 221 F 2 "" H 2900 1800 50 0001 C CNN 222 F 3 "http://www.ti.com/lit/gpn/sn74LS04" H 2900 1800 50 0001 C CNN 223 5 2900 1800 224 1 0 0 -1 225 $EndComp 226 $Comp 227 L 74xx:74LS04 IC? 228 U 4 1 61EEF8A7 229 P 3500 1800 230 AR Path="/61EEF8A7" Ref="IC?" Part="4" 231 AR Path="/61DF4BC2/61EEF8A7" Ref="IC8" Part="4" 232 F 0 "IC8" H 3500 2117 50 0000 C CNN 233 F 1 "74LS04" H 3500 2026 50 0000 C CNN 234 F 2 "" H 3500 1800 50 0001 C CNN 235 F 3 "http://www.ti.com/lit/gpn/sn74LS04" H 3500 1800 50 0001 C CNN 236 4 3500 1800 237 1 0 0 -1 238 $EndComp 239 $Comp 240 L Device:C C? 241 U 1 1 61EEF8AE 242 P 2450 1800 243 AR Path="/61EEF8AE" Ref="C?" Part="1" 244 AR Path="/61DF4BC2/61EEF8AE" Ref="C3" Part="1" 245 F 0 "C3" V 2198 1800 50 0000 C CNN 246 F 1 "100pF" V 2289 1800 50 0000 C CNN 247 F 2 "" H 2488 1650 50 0001 C CNN 248 F 3 "~" H 2450 1800 50 0001 C CNN 249 1 2450 1800 250 0 1 1 0 251 $EndComp 252 $Comp 253 L Device:C C? 254 U 1 1 61EEF8B5 255 P 3500 1000 256 AR Path="/61EEF8B5" Ref="C?" Part="1" 257 AR Path="/61DF4BC2/61EEF8B5" Ref="C4" Part="1" 258 F 0 "C4" V 3248 1000 50 0000 C CNN 259 F 1 "33pF" V 3339 1000 50 0000 C CNN 260 F 2 "" H 3538 850 50 0001 C CNN 261 F 3 "~" H 3500 1000 50 0001 C CNN 262 1 3500 1000 263 0 1 1 0 264 $EndComp 265 Wire Wire Line 266 1700 1800 1700 1300 267 Wire Wire Line 268 1700 1000 2300 1000 269 Wire Wire Line 270 1700 1300 1850 1300 271 Connection ~ 1700 1300 272 Wire Wire Line 273 1700 1300 1700 1000 274 Wire Wire Line 275 2300 1800 2300 1300 276 Wire Wire Line 277 2300 1300 2150 1300 278 Connection ~ 2300 1800 279 Wire Wire Line 280 2600 1800 2600 1300 281 Wire Wire Line 282 2600 1300 2750 1300 283 Connection ~ 2600 1800 284 Wire Wire Line 285 3050 1300 3200 1300 286 Wire Wire Line 287 3200 1300 3200 1800 288 Connection ~ 3200 1800 289 Wire Wire Line 290 3200 1300 3200 1000 291 Wire Wire Line 292 3200 1000 2600 1000 293 Connection ~ 3200 1300 294 Wire Wire Line 295 3200 1000 3350 1000 296 Connection ~ 3200 1000 297 Text GLabel 3750 1000 2 50 Input ~ 0 298 0V 299 Wire Wire Line 300 3750 1000 3650 1000 301 Wire Wire Line 302 3800 1800 4100 1800 303 Text Notes 1600 1300 2 50 ~ 0 304 Service Manual indicates\n820R values.\nIssue 4 board suggests\ngrey, red, brown, gold. 305 Text GLabel 5700 1100 2 50 Output ~ 0 306 CLOCK_16MHz 307 $Comp 308 L 74xx:74LS163 IC? 309 U 1 1 61F9FB39 310 P 6500 2700 311 AR Path="/61F9FB39" Ref="IC?" Part="1" 312 AR Path="/61DF4BC2/61F9FB39" Ref="IC9" Part="1" 313 F 0 "IC9" H 6200 3600 50 0000 C CNN 314 F 1 "74LS163" H 6200 3500 50 0000 C CNN 315 F 2 "" H 6500 2700 50 0001 C CNN 316 F 3 "http://www.ti.com/lit/gpn/sn74LS169" H 6500 2700 50 0001 C CNN 317 1 6500 2700 318 1 0 0 -1 319 $EndComp 320 Wire Wire Line 321 5900 2500 5900 2400 322 Wire Wire Line 323 5900 2400 6000 2400 324 Wire Wire Line 325 5900 2500 6000 2500 326 Wire Wire Line 327 7000 2500 7200 2500 328 Text GLabel 6500 3650 3 50 Input ~ 0 329 0V 330 Wire Wire Line 331 6500 3650 6500 3500 332 Text GLabel 6500 1800 1 50 Input ~ 0 333 5V 334 Wire Wire Line 335 6500 1900 6500 1800 336 Wire Wire Line 337 4100 3000 6000 3000 338 Text GLabel 5800 3200 0 50 Input ~ 0 339 0V 340 NoConn ~ 7000 2300 341 NoConn ~ 7000 2200 342 NoConn ~ 7000 2700 343 Wire Wire Line 344 5800 3200 5900 3200 345 Wire Wire Line 346 5900 2400 5900 2300 347 Wire Wire Line 348 5900 2300 6000 2300 349 Connection ~ 5900 2400 350 Wire Wire Line 351 5900 2300 5900 2200 352 Wire Wire Line 353 5900 2200 6000 2200 354 Connection ~ 5900 2300 355 $Comp 356 L 74xx:74LS00 U? 357 U 1 1 61F9FB55 358 P 7600 2500 359 AR Path="/61F9FB55" Ref="U?" Part="1" 360 AR Path="/61DF4BC2/61F9FB55" Ref="IC17" Part="1" 361 F 0 "IC17" H 7600 2825 50 0000 C CNN 362 F 1 "74LS00" H 7600 2734 50 0000 C CNN 363 F 2 "" H 7600 2500 50 0001 C CNN 364 F 3 "http://www.ti.com/lit/gpn/sn74ls00" H 7600 2500 50 0001 C CNN 365 1 7600 2500 366 1 0 0 -1 367 $EndComp 368 Wire Wire Line 369 7000 2400 7300 2400 370 Wire Wire Line 371 7200 2500 7200 2600 372 Wire Wire Line 373 7200 2600 7300 2600 374 Wire Wire Line 375 7900 2500 7900 1600 376 Wire Wire Line 377 7900 1600 5600 1600 378 Wire Wire Line 379 5600 1600 5600 2700 380 Wire Wire Line 381 5600 2700 6000 2700 382 Wire Wire Line 383 5900 2500 5900 2800 384 Connection ~ 5900 2500 385 Connection ~ 5900 3200 386 Wire Wire Line 387 5900 3200 6000 3200 388 Wire Wire Line 389 6000 2800 5900 2800 390 Connection ~ 5900 2800 391 Wire Wire Line 392 5900 2800 5900 2900 393 Wire Wire Line 394 6000 2900 5900 2900 395 Connection ~ 5900 2900 396 Wire Wire Line 397 5900 2900 5900 3200 398 Text Notes 6900 3300 0 50 ~ 0 399 Service Manual and issue 4\nuse 74LS169 for IC9. 400 Wire Wire Line 401 4100 3000 4100 1800 402 Connection ~ 4100 1800 403 Wire Wire Line 404 4100 1800 4100 1200 405 Text GLabel 8100 2800 2 50 Output ~ 0 406 CLOCK_16MHz_DIV_13 407 Wire Wire Line 408 8100 2800 7200 2800 409 Wire Wire Line 410 7200 2800 7200 2600 411 Connection ~ 7200 2600 412 Text Notes 4200 2550 0 50 ~ 0 413 Issue 6 boards tend to have\nIC18 (74LS08) fitted for\nsome kind of buffering\nof the clock signal.\n\nWithout it, LK10 is made to\ndeliver the signal directly,\nbut LK10 seems not to be made. 414 $Comp 415 L 74xx:74LS08 IC18 416 U 3 1 61F98BCB 417 P 5100 1100 418 F 0 "IC18" H 5100 1425 50 0000 C CNN 419 F 1 "74LS08" H 5100 1334 50 0000 C CNN 420 F 2 "" H 5100 1100 50 0001 C CNN 421 F 3 "http://www.ti.com/lit/gpn/sn74LS08" H 5100 1100 50 0001 C CNN 422 3 5100 1100 423 1 0 0 -1 424 $EndComp 425 Wire Wire Line 426 4100 1200 4800 1200 427 Text GLabel 4700 1000 0 50 Input ~ 0 428 BUFFER_ENABLE 429 Wire Wire Line 430 4700 1000 4800 1000 431 Wire Wire Line 432 5700 1100 5500 1100 433 $Comp 434 L Jumper:Jumper_2_Open LK10 435 U 1 1 61F9F418 436 P 4500 1800 437 F 0 "LK10" H 4500 2035 50 0000 C CNN 438 F 1 "Disable buffer" H 4500 1944 50 0000 C CNN 439 F 2 "" H 4500 1800 50 0001 C CNN 440 F 3 "~" H 4500 1800 50 0001 C CNN 441 1 4500 1800 442 1 0 0 -1 443 $EndComp 444 Wire Wire Line 445 4100 1800 4300 1800 446 Wire Wire Line 447 4700 1800 5500 1800 448 Wire Wire Line 449 5500 1800 5500 1100 450 Connection ~ 5500 1100 451 Wire Wire Line 452 5500 1100 5400 1100 453 $Comp 454 L 74xx:74LS00 IC17 455 U 5 1 61F8B195 456 P 9700 2700 457 F 0 "IC17" H 9930 2746 50 0000 L CNN 458 F 1 "74LS00" H 9930 2655 50 0000 L CNN 459 F 2 "" H 9700 2700 50 0001 C CNN 460 F 3 "http://www.ti.com/lit/gpn/sn74ls00" H 9700 2700 50 0001 C CNN 461 5 9700 2700 462 1 0 0 -1 463 $EndComp 464 Text GLabel 9700 2100 1 50 Input ~ 0 465 5V 466 Text GLabel 9700 3300 3 50 Input ~ 0 467 0V 468 Wire Wire Line 469 9700 2200 9700 2100 470 Wire Wire Line 471 9700 3300 9700 3200 472 Text Notes 8000 2300 0 50 ~ 0 473 IC17 label deduced from schematic. 474 $Comp 475 L Device:C_Variable VC1 476 U 1 1 61F8EF56 477 P 2700 2600 478 F 0 "VC1" V 2448 2600 50 0000 C CNN 479 F 1 "5.5-40pF" V 2539 2600 50 0000 C CNN 480 F 2 "" H 2700 2600 50 0001 C CNN 481 F 3 "~" H 2700 2600 50 0001 C CNN 482 1 2700 2600 483 0 1 1 0 484 $EndComp 485 Wire Wire Line 486 2550 2600 2350 2600 487 Text Notes 1600 2650 2 50 ~ 0 488 PAL video clock circuit. 489 $EndSCHEMATC