AcornElectronMainboard

clocks.sch

18:f1d60a768fbd
2022-07-05 Paul Boddie Added decoupling capacitors for RAM chips and tidied the layout somewhat.
     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