AcornElectronMainboard

AcornElectronMainboard.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 8268 11693 portrait     6 encoding utf-8     7 Sheet 1 9     8 Title "Acorn Electron Mainboard"     9 Date ""    10 Rev ""    11 Comp ""    12 Comment1 ""    13 Comment2 ""    14 Comment3 ""    15 Comment4 ""    16 $EndDescr    17 $Comp    18 L AcornElectron:ULA12C021 IC1    19 U 1 1 61CC86CA    20 P 4300 4100    21 F 0 "IC1" H 4300 6750 50  0000 C CNN    22 F 1 "ULA12C021" H 4300 6650 50  0000 C CNN    23 F 2 "" H 4300 4100 50  0001 C CNN    24 F 3 "" H 4300 4100 50  0001 C CNN    25 	1    4300 4100    26 	1    0    0    -1      27 $EndComp    28 Text Label 2900 3900 2    50   ~ 0    29 A0    30 Text Label 2900 4300 2    50   ~ 0    31 A4    32 Text Label 2900 4400 2    50   ~ 0    33 A5    34 Text Label 2900 4500 2    50   ~ 0    35 A6    36 Text Label 2900 4600 2    50   ~ 0    37 A7    38 Text Label 2900 4700 2    50   ~ 0    39 A8    40 Text Label 2900 4800 2    50   ~ 0    41 A9    42 Text Label 2900 4900 2    50   ~ 0    43 A10    44 Text Label 2900 5000 2    50   ~ 0    45 A11    46 Text Label 2900 5100 2    50   ~ 0    47 A12    48 Text Label 2900 5200 2    50   ~ 0    49 A13    50 Text Label 2900 5300 2    50   ~ 0    51 A14    52 Text Label 2900 4000 2    50   ~ 0    53 A1    54 Text Label 2900 4100 2    50   ~ 0    55 A2    56 Text Label 2900 4200 2    50   ~ 0    57 A3    58 Text Label 2900 5400 2    50   ~ 0    59 A15    60 Wire Bus Line    61 	1700 3800 2100 3800    62 Entry Wire Line    63 	2100 3800 2200 3900    64 Entry Wire Line    65 	2100 4000 2200 4100    66 Entry Wire Line    67 	2100 4100 2200 4200    68 Entry Wire Line    69 	2100 4200 2200 4300    70 Entry Wire Line    71 	2100 4300 2200 4400    72 Entry Wire Line    73 	2100 4400 2200 4500    74 Entry Wire Line    75 	2100 4500 2200 4600    76 Entry Wire Line    77 	2100 4600 2200 4700    78 Entry Wire Line    79 	2100 4700 2200 4800    80 Entry Wire Line    81 	2100 4800 2200 4900    82 Entry Wire Line    83 	2100 4900 2200 5000    84 Entry Wire Line    85 	2100 5000 2200 5100    86 Entry Wire Line    87 	2100 5100 2200 5200    88 Entry Wire Line    89 	2100 5200 2200 5300    90 Entry Wire Line    91 	2100 5300 2200 5400    92 Entry Wire Line    93 	2100 3900 2200 4000    94 Wire Wire Line    95 	2200 3900 2900 3900    96 Wire Wire Line    97 	2200 4000 2900 4000    98 Wire Wire Line    99 	2200 4100 2900 4100   100 Wire Wire Line   101 	2200 4200 2900 4200   102 Wire Wire Line   103 	2200 4300 2900 4300   104 Wire Wire Line   105 	2200 4400 2900 4400   106 Wire Wire Line   107 	2200 4500 2900 4500   108 Wire Wire Line   109 	2200 4600 2900 4600   110 Wire Wire Line   111 	2200 4700 2900 4700   112 Wire Wire Line   113 	2200 4800 2900 4800   114 Wire Wire Line   115 	2200 4900 2900 4900   116 Wire Wire Line   117 	2200 5000 2900 5000   118 Wire Wire Line   119 	2200 5100 2900 5100   120 Wire Wire Line   121 	2200 5200 2900 5200   122 Wire Wire Line   123 	2200 5300 2900 5300   124 Entry Wire Line   125 	2100 2300 2200 2400   126 Entry Wire Line   127 	2100 2400 2200 2500   128 Entry Wire Line   129 	2100 2500 2200 2600   130 Entry Wire Line   131 	2100 2600 2200 2700   132 Entry Wire Line   133 	2100 2700 2200 2800   134 Entry Wire Line   135 	2100 2800 2200 2900   136 Entry Wire Line   137 	2100 2900 2200 3000   138 Entry Wire Line   139 	2100 3000 2200 3100   140 Wire Wire Line   141 	2200 2400 2900 2400   142 Wire Wire Line   143 	2200 2500 2900 2500   144 Wire Wire Line   145 	2200 2600 2900 2600   146 Wire Wire Line   147 	2200 2700 2900 2700   148 Wire Wire Line   149 	2200 2800 2900 2800   150 Wire Wire Line   151 	2200 2900 2900 2900   152 Wire Wire Line   153 	2200 3000 2900 3000   154 Wire Wire Line   155 	2200 3100 2900 3100   156 Text Label 2900 2400 2    50   ~ 0   157 RA0   158 Text Label 2900 2500 2    50   ~ 0   159 RA1   160 Text Label 2900 2600 2    50   ~ 0   161 RA2   162 Text Label 2900 2700 2    50   ~ 0   163 RA3   164 Text Label 2900 2800 2    50   ~ 0   165 RA4   166 Text Label 2900 2900 2    50   ~ 0   167 RA5   168 Text Label 2900 3000 2    50   ~ 0   169 RA6   170 Text Label 2900 3100 2    50   ~ 0   171 RA7   172 Wire Wire Line   173 	2300 2100 2900 2100   174 Wire Wire Line   175 	2500 2200 2900 2200   176 Text Label 2900 2100 2    50   ~ 0   177 ~WE   178 Text Label 2900 2200 2    50   ~ 0   179 ~RAS   180 Text Label 2900 2300 2    50   ~ 0   181 ~CAS   182 Wire Wire Line   183 	2200 2000 2900 2000   184 Wire Wire Line   185 	2900 1900 2200 1900   186 Wire Wire Line   187 	2900 1800 2200 1800   188 Wire Wire Line   189 	2900 1700 2200 1700   190 Entry Wire Line   191 	2100 1600 2200 1700   192 Entry Wire Line   193 	2100 1700 2200 1800   194 Entry Wire Line   195 	2100 1800 2200 1900   196 Entry Wire Line   197 	2100 1900 2200 2000   198 Text Label 2900 1700 2    50   ~ 0   199 RAM0   200 Text Label 2900 1800 2    50   ~ 0   201 RAM1   202 Text Label 2900 1900 2    50   ~ 0   203 RAM2   204 Text Label 2900 2000 2    50   ~ 0   205 RAM3   206 Text Label 2900 5500 2    50   ~ 0   207 D0   208 Text Label 2900 5600 2    50   ~ 0   209 D1   210 Text Label 2900 5700 2    50   ~ 0   211 D2   212 Text Label 2900 5800 2    50   ~ 0   213 D3   214 Text Label 2900 5900 2    50   ~ 0   215 D4   216 Text Label 2900 6000 2    50   ~ 0   217 D5   218 Text Label 2900 6100 2    50   ~ 0   219 D6   220 Text Label 2900 6200 2    50   ~ 0   221 D7   222 Wire Wire Line   223 	2900 3800 2300 3800   224 Wire Wire Line   225 	2300 3800 2300 3700   226 Entry Wire Line   227 	2100 3100 2200 3200   228 Entry Wire Line   229 	2100 3200 2200 3300   230 Entry Wire Line   231 	2100 3300 2200 3400   232 Entry Wire Line   233 	2100 3400 2200 3500   234 Wire Wire Line   235 	2200 3200 2900 3200   236 Wire Wire Line   237 	2200 3300 2900 3300   238 Wire Wire Line   239 	2200 3400 2900 3400   240 Wire Wire Line   241 	2200 3500 2900 3500   242 $Comp   243 L Connector_Generic:Conn_01x03 PL3   244 U 1 1 61CF9DF4   245 P 1400 8900   246 F 0 "PL3" H 1320 9217 50  0000 C CNN   247 F 1 "Power" H 1320 9126 50  0000 C CNN   248 F 2 "" H 1400 8900 50  0001 C CNN   249 F 3 "~" H 1400 8900 50  0001 C CNN   250 	1    1400 8900   251 	-1   0    0    -1     252 $EndComp   253 Text GLabel 3700 8800 2    50   Output ~ 0   254 5V   255 Wire Wire Line   256 	1600 8800 2100 8800   257 Text GLabel 3700 9300 2    50   Output ~ 0   258 0V   259 Text GLabel 3700 9800 2    50   Output ~ 0   260 -5V   261 Wire Wire Line   262 	1900 9300 2000 9300   263 Wire Wire Line   264 	1800 9800 2000 9800   265 Text GLabel 3800 7100 3    50   Input ~ 0   266 0V   267 Wire Wire Line   268 	3800 7100 3800 6900   269 Wire Wire Line   270 	3800 6900 4000 6900   271 Wire Wire Line   272 	4000 6900 4000 6750   273 Connection ~ 3800 6900   274 Wire Wire Line   275 	3800 6900 3800 6750   276 Text GLabel 3600 700  1    50   Input ~ 0   277 5V   278 Wire Wire Line   279 	3600 700  3600 800    280 $Comp   281 L Device:R R5   282 U 1 1 61F10DD6   283 P 3800 1050   284 F 0 "R5" H 3650 1100 50  0000 L CNN   285 F 1 "24R" H 3750 1000 50  0000 R CNN   286 F 2 "" V 3730 1050 50  0001 C CNN   287 F 3 "~" H 3800 1050 50  0001 C CNN   288 	1    3800 1050   289 	1    0    0    -1     290 $EndComp   291 $Comp   292 L Device:R R58   293 U 1 1 61F10E39   294 P 4000 1050   295 F 0 "R58" H 4050 1100 50  0000 L CNN   296 F 1 "24R" H 4050 1000 50  0000 L CNN   297 F 2 "" V 3930 1050 50  0001 C CNN   298 F 3 "~" H 4000 1050 50  0001 C CNN   299 	1    4000 1050   300 	1    0    0    -1     301 $EndComp   302 Wire Wire Line   303 	3800 1550 3800 1350   304 Wire Wire Line   305 	3800 900  3800 800    306 Wire Wire Line   307 	3800 800  3600 800    308 Connection ~ 3600 800    309 Wire Wire Line   310 	3600 800  3600 1550   311 Wire Wire Line   312 	4000 800  3800 800    313 Connection ~ 3800 800    314 $Comp   315 L Device:C C27   316 U 1 1 61FBBBB4   317 P 3350 1250   318 F 0 "C27" H 3250 1300 50  0000 R CNN   319 F 1 "10??F/TANT" H 3250 1200 38  0000 R CNN   320 F 2 "" H 3388 1100 50  0001 C CNN   321 F 3 "~" H 3350 1250 50  0001 C CNN   322 	1    3350 1250   323 	1    0    0    -1     324 $EndComp   325 Wire Wire Line   326 	3600 800  3350 800    327 Wire Wire Line   328 	3350 800  3350 1100   329 Text GLabel 3250 1500 0    50   Input ~ 0   330 0V   331 Wire Wire Line   332 	3250 1500 3350 1500   333 Wire Wire Line   334 	3350 1500 3350 1400   335 $Comp   336 L Device:C Ax19   337 U 1 1 621AFB3A   338 P 2700 9050   339 F 0 "Ax19" H 2815 9096 50  0000 L CNN   340 F 1 "47nF" H 2815 9005 50  0000 L CNN   341 F 2 "" H 2738 8900 50  0001 C CNN   342 F 3 "~" H 2700 9050 50  0001 C CNN   343 	1    2700 9050   344 	1    0    0    -1     345 $EndComp   346 $Comp   347 L Device:C Ax1   348 U 1 1 62245E33   349 P 2600 9550   350 F 0 "Ax1" H 2715 9596 50  0000 L CNN   351 F 1 "47nF" H 2715 9505 50  0000 L CNN   352 F 2 "" H 2638 9400 50  0001 C CNN   353 F 3 "~" H 2600 9550 50  0001 C CNN   354 	1    2600 9550   355 	1    0    0    -1     356 $EndComp   357 $Comp   358 L Device:CP C1   359 U 1 1 62245FAE   360 P 2100 9050   361 F 0 "C1" H 2218 9096 50  0000 L CNN   362 F 1 "47??F/16V" H 2218 9005 38  0000 L CNN   363 F 2 "" H 2138 8900 50  0001 C CNN   364 F 3 "~" H 2100 9050 50  0001 C CNN   365 	1    2100 9050   366 	1    0    0    -1     367 $EndComp   368 $Comp   369 L Device:CP C2   370 U 1 1 62245FF4   371 P 2000 9550   372 F 0 "C2" H 2118 9596 50  0000 L CNN   373 F 1 "10??F/16V" H 2118 9505 38  0000 L CNN   374 F 2 "" H 2038 9400 50  0001 C CNN   375 F 3 "~" H 2000 9550 50  0001 C CNN   376 	1    2000 9550   377 	1    0    0    -1     378 $EndComp   379 Wire Wire Line   380 	1900 9300 1900 8900   381 Wire Wire Line   382 	1900 8900 1600 8900   383 Wire Wire Line   384 	1800 9800 1800 9000   385 Wire Wire Line   386 	2100 8900 2100 8800   387 Connection ~ 2100 8800   388 Wire Wire Line   389 	2100 8800 2700 8800   390 Wire Wire Line   391 	2000 9400 2000 9300   392 Connection ~ 2000 9300   393 Wire Wire Line   394 	2000 9300 2100 9300   395 Wire Wire Line   396 	2100 9200 2100 9300   397 Connection ~ 2100 9300   398 Wire Wire Line   399 	2100 9300 2600 9300   400 Wire Wire Line   401 	2000 9700 2000 9800   402 Connection ~ 2000 9800   403 Wire Wire Line   404 	2000 9800 2600 9800   405 Wire Wire Line   406 	2600 9800 2600 9700   407 Connection ~ 2600 9800   408 Wire Wire Line   409 	2600 9400 2600 9300   410 Connection ~ 2600 9300   411 Wire Wire Line   412 	2600 9300 2700 9300   413 Wire Wire Line   414 	2700 9300 2700 9200   415 Connection ~ 2700 9300   416 Wire Wire Line   417 	2700 8900 2700 8800   418 Connection ~ 2700 8800   419 $Comp   420 L Connector_Generic:Conn_01x02 PL4   421 U 1 1 627DA4FF   422 P 1400 10100   423 F 0 "PL4" H 1320 10317 50  0000 C CNN   424 F 1 "Power" H 1320 10226 50  0000 C CNN   425 F 2 "" H 1400 10100 50  0001 C CNN   426 F 3 "~" H 1400 10100 50  0001 C CNN   427 	1    1400 10100   428 	-1   0    0    -1     429 $EndComp   430 Wire Wire Line   431 	3600 6750 3600 7400   432 Wire Wire Line   433 	3600 7400 3500 7400   434 Text Label 1600 8800 0    50   ~ 0   435 5V   436 Text Label 1600 8900 0    50   ~ 0   437 0V   438 Wire Wire Line   439 	1600 9000 1800 9000   440 Text Label 1600 9000 0    50   ~ 0   441 -5V   442 Text Label 1600 10100 0    50   ~ 0   443 RETURN   444 Text Label 1600 10200 0    50   ~ 0   445 18VAC   446 Wire Wire Line   447 	4600 7600 4600 6750   448 $Sheet   449 S 2800 7800 700  300    450 U 61DF4BC2   451 F0 "Clocks" 50   452 F1 "clocks.sch" 50   453 $EndSheet   454 Text GLabel 3500 7600 0    50   Input ~ 0   455 CLOCK_16MHz   456 Text GLabel 3500 7400 0    50   Input ~ 0   457 CLOCK_16MHz_DIV_13   458 $Sheet   459 S 1200 1100 700  300    460 U 61D7EEE8   461 F0 "RAM" 50   462 F1 "RAM.sch" 50   463 $EndSheet   464 Wire Bus Line   465 	2100 2300 1700 2300   466 Text GLabel 1700 1600 0    50   BiDi ~ 0   467 RAM[0..3]   468 Text GLabel 1700 2300 0    50   Output ~ 0   469 RA[0..7]   470 $Sheet   471 S 5800 1300 700  300    472 U 624B50A6   473 F0 "Cassette" 50   474 F1 "cassette.sch" 50   475 $EndSheet   476 Text GLabel 5800 3600 2    50   Input ~ 0   477 CASSETTE_INPUT   478 Wire Wire Line   479 	5600 3600 5800 3600   480 Text GLabel 5800 1800 2    50   Output ~ 0   481 CASSETTE_OUTPUT   482 Wire Wire Line   483 	5600 1800 5800 1800   484 $Sheet   485 S 5800 4200 700  300    486 U 61E9B87F   487 F0 "Sound" 50   488 F1 "sound.sch" 50   489 $EndSheet   490 Text GLabel 5800 4700 2    50   Output ~ 0   491 SOUND_OUTPUT   492 Wire Wire Line   493 	5600 4700 5800 4700   494 Text GLabel 2600 10100 2    50   UnSpc ~ 0   495 POWER_AC_RETURN   496 Text GLabel 2600 10200 2    50   UnSpc ~ 0   497 POWER_18VAC   498 Wire Wire Line   499 	1600 10100 2100 10100   500 Wire Wire Line   501 	1600 10200 2100 10200   502 Wire Wire Line   503 	3500 7600 4600 7600   504 Text GLabel 1700 6400 0    50   Output ~ 0   505 PHI_OUT   506 $Sheet   507 S 1300 7800 700  300    508 U 61FB7D7E   509 F0 "Expansion" 50   510 F1 "expansion.sch" 50   511 $EndSheet   512 Text GLabel 1700 5400 0    50   BiDi ~ 0   513 D[0..7]   514 Wire Bus Line   515 	1700 5400 2100 5400   516 Text GLabel 1700 3800 0    50   Input ~ 0   517 A[0..15]   518 Text GLabel 1700 6600 0    50   Input ~ 0   519 RnW   520 Text GLabel 2000 6500 0    50   Output ~ 0   521 ~IRQ   522 Text GLabel 2000 6300 0    50   Input ~ 0   523 ~NMI   524 Text GLabel 2700 3700 0    50   Input ~ 0   525 ~RST   526 $Sheet   527 S 1300 6800 700  300    528 U 61F2273C   529 F0 "CPU, ROM, keyboard" 50   530 F1 "CPU_ROM_KBD.sch" 50   531 $EndSheet   532 Text GLabel 1700 3100 0    50   Input ~ 0   533 KBD[0..3]   534 Wire Bus Line   535 	1700 3100 2100 3100   536 Wire Wire Line   537 	2700 3700 2900 3700   538 Entry Wire Line   539 	2100 5400 2200 5500   540 Entry Wire Line   541 	2100 5500 2200 5600   542 Entry Wire Line   543 	2100 5600 2200 5700   544 Entry Wire Line   545 	2100 5700 2200 5800   546 Entry Wire Line   547 	2100 5800 2200 5900   548 Entry Wire Line   549 	2100 5900 2200 6000   550 Entry Wire Line   551 	2100 6000 2200 6100   552 Entry Wire Line   553 	2100 6100 2200 6200   554 Wire Wire Line   555 	2200 5500 2900 5500   556 Wire Wire Line   557 	2200 5600 2900 5600   558 Wire Wire Line   559 	2200 5700 2900 5700   560 Wire Wire Line   561 	2200 5800 2900 5800   562 Wire Wire Line   563 	2200 5900 2900 5900   564 Wire Wire Line   565 	2200 6000 2900 6000   566 Wire Wire Line   567 	2200 6100 2900 6100   568 Wire Wire Line   569 	2200 6200 2900 6200   570 Text GLabel 1700 3600 0    50   Input ~ 0   571 CAPS_LOCK   572 Wire Wire Line   573 	2200 5400 2900 5400   574 Text GLabel 1000 3700 0    50   Output ~ 0   575 ROM   576 Wire Wire Line   577 	1700 3600 2900 3600   578 Wire Wire Line   579 	2300 3700 1000 3700   580 Wire Wire Line   581 	2000 6300 2900 6300   582 Wire Wire Line   583 	2000 6500 2900 6500   584 Wire Wire Line   585 	1700 6600 2900 6600   586 Wire Wire Line   587 	1700 6400 2900 6400   588 $Sheet   589 S 4800 7800 700  300    590 U 61DB955D   591 F0 "Video" 50   592 F1 "video.sch" 50   593 $EndSheet   594 Wire Wire Line   595 	6300 5500 6200 5500   596 Wire Wire Line   597 	6300 5100 6200 5100   598 Wire Wire Line   599 	5800 5100 5900 5100   600 Wire Wire Line   601 	5800 5500 5900 5500   602 Wire Wire Line   603 	5800 5300 5800 5100   604 Wire Wire Line   605 	5800 5300 5800 5500   606 Connection ~ 5800 5300   607 Wire Wire Line   608 	5600 5300 5800 5300   609 Text GLabel 6300 5500 2    50   Input ~ 0   610 0V   611 $Comp   612 L Device:C C9   613 U 1 1 621AE941   614 P 6050 5500   615 F 0 "C9" V 5798 5500 50  0000 C CNN   616 F 1 "1??F/35V/TANT" V 5889 5500 38  0000 C CNN   617 F 2 "" H 6088 5350 50  0001 C CNN   618 F 3 "~" H 6050 5500 50  0001 C CNN   619 	1    6050 5500   620 	0    1    1    0      621 $EndComp   622 Text GLabel 6300 5100 2    50   Input ~ 0   623 5V   624 $Comp   625 L Device:R R7   626 U 1 1 61FA16A2   627 P 6050 5100   628 F 0 "R7" V 5843 5100 50  0000 C CNN   629 F 1 "56000R" V 5934 5100 50  0000 C CNN   630 F 2 "" V 5980 5100 50  0001 C CNN   631 F 3 "~" H 6050 5100 50  0001 C CNN   632 	1    6050 5100   633 	0    1    1    0      634 $EndComp   635 Text GLabel 7100 6100 2    50   Output ~ 0   636 ~CSYNC   637 Text GLabel 7100 6700 2    50   Output ~ 0   638 BLUE   639 Text GLabel 7100 7300 2    50   Output ~ 0   640 GREEN   641 Text GLabel 7100 7900 2    50   Output ~ 0   642 RED   643 Wire Wire Line   644 	5600 5700 6100 5700   645 Text GLabel 4900 7000 2    50   Output ~ 0   646 ~HS   647 Wire Wire Line   648 	4800 6750 4800 7000   649 Wire Wire Line   650 	4800 7000 4900 7000   651 Text GLabel 5800 2300 2    50   BiDi ~ 0   652 CASSETTE_RC   653 Text GLabel 5800 2600 2    50   Output ~ 0   654 CASSETTE_MOTOR   655 Wire Wire Line   656 	5600 2300 5800 2300   657 Wire Wire Line   658 	5600 2600 5800 2600   659 $Sheet   660 S 4800 7200 700  300    661 U 62411C42   662 F0 "UHF" 50   663 F1 "UHF.sch" 50   664 $EndSheet   665 Wire Wire Line   666 	5600 6300 5800 6300   667 Wire Wire Line   668 	5600 5900 6000 5900   669 Text Notes 5800 9150 0    50   ~ 0   670 Issue 6 boards tend to have\nIC19 (74LS08) fitted for\nsome kind of buffering\nof the video signals.\n\nLK7 is supposedly connected\nto +5V to ensure this.   671 $Comp   672 L 74xx:74LS08 IC19   673 U 1 1 61E3E3E3   674 P 6700 7300   675 F 0 "IC19" H 6700 7625 50  0000 C CNN   676 F 1 "74LS08" H 6700 7534 50  0000 C CNN   677 F 2 "" H 6700 7300 50  0001 C CNN   678 F 3 "http://www.ti.com/lit/gpn/sn74LS08" H 6700 7300 50  0001 C CNN   679 	1    6700 7300   680 	1    0    0    -1     681 $EndComp   682 $Comp   683 L 74xx:74LS08 IC19   684 U 2 1 61E3E49E   685 P 6700 7900   686 F 0 "IC19" H 6700 8225 50  0000 C CNN   687 F 1 "74LS08" H 6700 8134 50  0000 C CNN   688 F 2 "" H 6700 7900 50  0001 C CNN   689 F 3 "http://www.ti.com/lit/gpn/sn74LS08" H 6700 7900 50  0001 C CNN   690 	2    6700 7900   691 	1    0    0    -1     692 $EndComp   693 $Comp   694 L 74xx:74LS08 IC19   695 U 3 1 61E3E509   696 P 6700 6100   697 F 0 "IC19" H 6700 6425 50  0000 C CNN   698 F 1 "74LS08" H 6700 6334 50  0000 C CNN   699 F 2 "" H 6700 6100 50  0001 C CNN   700 F 3 "http://www.ti.com/lit/gpn/sn74LS08" H 6700 6100 50  0001 C CNN   701 	3    6700 6100   702 	1    0    0    -1     703 $EndComp   704 $Comp   705 L 74xx:74LS08 IC19   706 U 4 1 61E3E573   707 P 6700 6700   708 F 0 "IC19" H 6700 7025 50  0000 C CNN   709 F 1 "74LS08" H 6700 6934 50  0000 C CNN   710 F 2 "" H 6700 6700 50  0001 C CNN   711 F 3 "http://www.ti.com/lit/gpn/sn74LS08" H 6700 6700 50  0001 C CNN   712 	4    6700 6700   713 	1    0    0    -1     714 $EndComp   715 $Comp   716 L 74xx:74LS08 IC19   717 U 5 1 61E3E5E4   718 P 7200 8900   719 F 0 "IC19" H 7430 8946 50  0000 L CNN   720 F 1 "74LS08" H 7430 8855 50  0000 L CNN   721 F 2 "" H 7200 8900 50  0001 C CNN   722 F 3 "http://www.ti.com/lit/gpn/sn74LS08" H 7200 8900 50  0001 C CNN   723 	5    7200 8900   724 	1    0    0    -1     725 $EndComp   726 Wire Wire Line   727 	5800 6300 5800 7800   728 Wire Wire Line   729 	5800 7800 6400 7800   730 Wire Wire Line   731 	5900 6100 5900 7200   732 Wire Wire Line   733 	5900 7200 6400 7200   734 Wire Wire Line   735 	5600 6100 5900 6100   736 Wire Wire Line   737 	6000 5900 6000 6800   738 Wire Wire Line   739 	6000 6800 6400 6800   740 Wire Wire Line   741 	6100 5700 6100 6200   742 Wire Wire Line   743 	6100 6200 6400 6200   744 $Comp   745 L Jumper:Jumper_2_Bridged LK7   746 U 1 1 61EC346B   747 P 6600 8400   748 F 0 "LK7" H 6600 8595 50  0000 C CNN   749 F 1 "Jumper_2_Bridged" H 6600 8504 50  0000 C CNN   750 F 2 "" H 6600 8400 50  0001 C CNN   751 F 3 "~" H 6600 8400 50  0001 C CNN   752 	1    6600 8400   753 	1    0    0    -1     754 $EndComp   755 Wire Wire Line   756 	6400 8000 6200 8000   757 Wire Wire Line   758 	6200 8000 6200 8400   759 Wire Wire Line   760 	6200 8400 6400 8400   761 Wire Wire Line   762 	6200 8000 6200 7400   763 Wire Wire Line   764 	6200 7400 6400 7400   765 Connection ~ 6200 8000   766 Wire Wire Line   767 	6200 7400 6200 6600   768 Wire Wire Line   769 	6200 6600 6400 6600   770 Connection ~ 6200 7400   771 Wire Wire Line   772 	6200 6600 6200 6000   773 Wire Wire Line   774 	6200 6000 6400 6000   775 Connection ~ 6200 6600   776 Wire Wire Line   777 	7000 6100 7100 6100   778 Wire Wire Line   779 	7000 6700 7100 6700   780 Wire Wire Line   781 	7000 7300 7100 7300   782 Wire Wire Line   783 	7000 7900 7100 7900   784 Text GLabel 6900 8400 2    50   Input ~ 0   785 5V   786 Wire Wire Line   787 	6900 8400 6800 8400   788 Text GLabel 7200 8300 1    50   Input ~ 0   789 5V   790 Wire Wire Line   791 	7200 8300 7200 8400   792 Text GLabel 7200 9500 3    50   Input ~ 0   793 0V   794 Wire Wire Line   795 	7200 9500 7200 9400   796 Text GLabel 6100 8400 0    50   Output ~ 0   797 BUFFER_ENABLE   798 Wire Wire Line   799 	6100 8400 6200 8400   800 Connection ~ 6200 8400   801 Text Notes 1400 10600 0    50   ~ 0   802 PL4 introduced for the two separate connections\non the original board.   803 Text Label 2100 5400 2    50   ~ 0   804 D[0..7]   805 Text Label 2100 3800 2    50   ~ 0   806 A[0..15]   807 Text Label 2100 3100 2    50   ~ 0   808 KBD[0..3]   809 Text Label 2100 2300 2    50   ~ 0   810 RA[0..7]   811 Text GLabel 2300 2100 0    50   Output ~ 0   812 ~WE   813 Text GLabel 2500 2200 0    50   Output ~ 0   814 ~RAS   815 Text GLabel 2700 2300 0    50   Output ~ 0   816 ~CAS   817 Wire Wire Line   818 	2900 2300 2700 2300   819 Text Label 2900 3200 2    50   ~ 0   820 KBD0   821 Text Label 2900 3300 2    50   ~ 0   822 KBD1   823 Text Label 2900 3400 2    50   ~ 0   824 KBD2   825 Text Label 2900 3500 2    50   ~ 0   826 KBD3   827 $Comp   828 L power:PWR_FLAG #FLG0104   829 U 1 1 62281B8F   830 P 2100 10100   831 F 0 "#FLG0104" H 2100 10175 50  0001 C CNN   832 F 1 "PWR_FLAG" H 2100 10274 50  0000 C CNN   833 F 2 "" H 2100 10100 50  0001 C CNN   834 F 3 "~" H 2100 10100 50  0001 C CNN   835 	1    2100 10100   836 	1    0    0    -1     837 $EndComp   838 Connection ~ 2100 10100   839 Wire Wire Line   840 	2100 10100 2600 10100   841 $Comp   842 L power:PWR_FLAG #FLG0105   843 U 1 1 62281BE9   844 P 2100 10200   845 F 0 "#FLG0105" H 2100 10275 50  0001 C CNN   846 F 1 "PWR_FLAG" H 2100 10373 50  0000 C CNN   847 F 2 "" H 2100 10200 50  0001 C CNN   848 F 3 "~" H 2100 10200 50  0001 C CNN   849 	1    2100 10200   850 	-1   0    0    1      851 $EndComp   852 Connection ~ 2100 10200   853 Wire Wire Line   854 	2100 10200 2600 10200   855 Wire Wire Line   856 	4000 900  4000 800    857 Wire Wire Line   858 	4000 1550 4000 1250   859 $Comp   860 L power:+5V #PWR0101   861 U 1 1 61F9A343   862 P 3500 8600   863 F 0 "#PWR0101" H 3500 8450 50  0001 C CNN   864 F 1 "+5V" H 3515 8773 50  0000 C CNN   865 F 2 "" H 3500 8600 50  0001 C CNN   866 F 3 "" H 3500 8600 50  0001 C CNN   867 	1    3500 8600   868 	1    0    0    -1     869 $EndComp   870 $Comp   871 L power:GND #PWR0102   872 U 1 1 61FAE014   873 P 3300 9500   874 F 0 "#PWR0102" H 3300 9250 50  0001 C CNN   875 F 1 "GND" H 3305 9327 50  0000 C CNN   876 F 2 "" H 3300 9500 50  0001 C CNN   877 F 3 "" H 3300 9500 50  0001 C CNN   878 	1    3300 9500   879 	1    0    0    -1     880 $EndComp   881 $Comp   882 L power:-5V #PWR0103   883 U 1 1 61FAE0AD   884 P 3500 9600   885 F 0 "#PWR0103" H 3500 9700 50  0001 C CNN   886 F 1 "-5V" H 3515 9773 50  0000 C CNN   887 F 2 "" H 3500 9600 50  0001 C CNN   888 F 3 "" H 3500 9600 50  0001 C CNN   889 	1    3500 9600   890 	1    0    0    -1     891 $EndComp   892 Wire Wire Line   893 	2700 8800 3500 8800   894 Wire Wire Line   895 	2600 9800 3500 9800   896 Wire Wire Line   897 	2700 9300 3300 9300   898 Connection ~ 3500 8800   899 Wire Wire Line   900 	3500 8800 3700 8800   901 Wire Wire Line   902 	3300 9500 3300 9400   903 Connection ~ 3300 9300   904 Wire Wire Line   905 	3300 9300 3700 9300   906 Wire Wire Line   907 	3500 9800 3500 9700   908 Connection ~ 3500 9800   909 Wire Wire Line   910 	3500 9800 3700 9800   911 $Comp   912 L power:PWR_FLAG #FLG0101   913 U 1 1 61FD1C8B   914 P 3500 8700   915 F 0 "#FLG0101" H 3500 8775 50  0001 C CNN   916 F 1 "PWR_FLAG" V 3500 8828 50  0000 L CNN   917 F 2 "" H 3500 8700 50  0001 C CNN   918 F 3 "~" H 3500 8700 50  0001 C CNN   919 	1    3500 8700   920 	0    -1   -1   0      921 $EndComp   922 $Comp   923 L power:PWR_FLAG #FLG0102   924 U 1 1 61FD1D09   925 P 3500 9700   926 F 0 "#FLG0102" H 3500 9775 50  0001 C CNN   927 F 1 "PWR_FLAG" V 3500 9828 50  0000 L CNN   928 F 2 "" H 3500 9700 50  0001 C CNN   929 F 3 "~" H 3500 9700 50  0001 C CNN   930 	1    3500 9700   931 	0    1    1    0      932 $EndComp   933 $Comp   934 L power:PWR_FLAG #FLG0103   935 U 1 1 61FD8A1C   936 P 3300 9400   937 F 0 "#FLG0103" H 3300 9475 50  0001 C CNN   938 F 1 "PWR_FLAG" V 3300 9528 50  0000 L CNN   939 F 2 "" H 3300 9400 50  0001 C CNN   940 F 3 "~" H 3300 9400 50  0001 C CNN   941 	1    3300 9400   942 	0    -1   -1   0      943 $EndComp   944 Connection ~ 3300 9400   945 Wire Wire Line   946 	3300 9400 3300 9300   947 Wire Wire Line   948 	3500 8600 3500 8700   949 Connection ~ 3500 8700   950 Wire Wire Line   951 	3500 8700 3500 8800   952 Connection ~ 3500 9700   953 Wire Wire Line   954 	3500 9600 3500 9700   955 $Comp   956 L power:PWR_FLAG #FLG0106   957 U 1 1 62024979   958 P 4000 1250   959 F 0 "#FLG0106" H 4000 1325 50  0001 C CNN   960 F 1 "PWR_FLAG" V 4000 1378 50  0000 L CNN   961 F 2 "" H 4000 1250 50  0001 C CNN   962 F 3 "~" H 4000 1250 50  0001 C CNN   963 	1    4000 1250   964 	0    1    1    0      965 $EndComp   966 Connection ~ 4000 1250   967 Wire Wire Line   968 	4000 1250 4000 1200   969 $Comp   970 L power:PWR_FLAG #FLG0107   971 U 1 1 620249E5   972 P 3800 1350   973 F 0 "#FLG0107" H 3800 1425 50  0001 C CNN   974 F 1 "PWR_FLAG" V 3800 1650 50  0000 L CNN   975 F 2 "" H 3800 1350 50  0001 C CNN   976 F 3 "~" H 3800 1350 50  0001 C CNN   977 	1    3800 1350   978 	0    1    1    0      979 $EndComp   980 Connection ~ 3800 1350   981 Wire Wire Line   982 	3800 1350 3800 1200   983 Text Notes 4550 1400 0    50   ~ 0   984 Note that KiCad gets upset\nwhen connecting passives\nto power input pins.   985 Wire Bus Line   986 	1700 1600 2100 1600   987 Wire Bus Line   988 	2100 1600 2100 1900   989 Wire Bus Line   990 	2100 3100 2100 3400   991 Wire Bus Line   992 	2100 2300 2100 3000   993 Wire Bus Line   994 	2100 5400 2100 6100   995 Wire Bus Line   996 	2100 3800 2100 5300   997 $EndSCHEMATC