ram.sch

EESchema Schematic File Version 4
EELAYER 30 0
EELAYER END
$Descr A4 11693 8268
encoding utf-8
Sheet 4 12
Title "LittleSixteen"
Date "2021-11-28"
Rev "3git"
Comp "SukkoPera"
Comment1 "Licensed under CC BY-NC-SA 4.0"
Comment2 "WARNING: These schematics might contain errors!"
Comment3 ""
Comment4 ""
$EndDescr
Entry Wire Line
	10035 2140 10135 2240
Entry Wire Line
	10035 2240 10135 2340
Entry Wire Line
	10035 2340 10135 2440
Entry Wire Line
	10035 2440 10135 2540
Entry Wire Line
	10035 3840 10135 3940
Entry Wire Line
	10035 3940 10135 4040
Entry Wire Line
	10035 4040 10135 4140
Entry Wire Line
	10035 4140 10135 4240
Text Label 9805 2140 0    60   ~ 0
m0
Text Label 9805 2240 0    60   ~ 0
m1
Text Label 9805 2340 0    60   ~ 0
m2
Text Label 9805 2440 0    60   ~ 0
m3
Text Label 9805 2540 0    60   ~ 0
m7
Text Label 9805 3840 0    60   ~ 0
m0
Text Label 9805 3940 0    60   ~ 0
m1
Text Label 9805 4040 0    60   ~ 0
m2
Text Label 9805 4140 0    60   ~ 0
m3
Text Label 9805 4240 0    60   ~ 0
m7
Entry Wire Line
	7165 2340 7265 2240
Entry Wire Line
	7165 2440 7265 2340
Entry Wire Line
	7165 2540 7265 2440
Text Label 7515 2240 0    60   ~ 0
m6
Text Label 7515 2340 0    60   ~ 0
m5
Text Label 7515 2440 0    60   ~ 0
m4
Entry Wire Line
	7165 4040 7265 3940
Entry Wire Line
	7165 4140 7265 4040
Entry Wire Line
	7165 4240 7265 4140
Text Label 7515 3940 0    60   ~ 0
m6
Text Label 7515 4040 0    60   ~ 0
m5
Text Label 7515 4140 0    60   ~ 0
m4
Entry Wire Line
	10235 2040 10335 1940
Entry Wire Line
	10235 1840 10335 1740
Entry Wire Line
	6965 1740 7065 1840
Entry Wire Line
	6965 1840 7065 1940
Text Label 7515 1840 0    60   ~ 0
d4
Text Label 7515 1940 0    60   ~ 0
d5
Text Label 9805 1840 0    60   ~ 0
d7
Text Label 9805 2040 0    60   ~ 0
d6
Entry Wire Line
	10235 3740 10335 3640
Text Label 9805 3540 0    60   ~ 0
d3
Text Label 9805 3740 0    60   ~ 0
d2
Entry Wire Line
	6965 3440 7065 3540
Entry Wire Line
	6965 3540 7065 3640
Text Label 7515 3540 0    60   ~ 0
d0
Text Label 7515 3640 0    60   ~ 0
d1
Entry Wire Line
	4660 1590 4760 1690
Entry Wire Line
	4660 1890 4760 1990
Entry Wire Line
	4660 2190 4760 2290
Entry Wire Line
	4660 2490 4760 2590
Entry Wire Line
	10035 2540 10135 2640
Entry Wire Line
	10035 4240 10135 4340
Text Label 4460 1590 0    60   ~ 0
m0
Text Label 4460 1890 0    60   ~ 0
m1
Wire Wire Line
	9460 1740 9560 1740
Wire Wire Line
	9460 2140 10035 2140
Wire Wire Line
	9460 2240 10035 2240
Wire Wire Line
	9460 2340 10035 2340
Wire Wire Line
	9460 2440 10035 2440
Wire Wire Line
	9460 2540 10035 2540
Wire Wire Line
	9460 3840 10035 3840
Wire Wire Line
	9460 3940 10035 3940
Wire Wire Line
	9460 4040 10035 4040
Wire Wire Line
	9460 4140 10035 4140
Wire Wire Line
	9460 4240 10035 4240
Wire Wire Line
	7315 3840 7960 3840
Wire Wire Line
	7315 1155 7315 2140
Wire Wire Line
	7315 2140 7960 2140
Wire Wire Line
	7960 2240 7265 2240
Wire Wire Line
	7960 2340 7265 2340
Wire Wire Line
	7960 2440 7265 2440
Wire Wire Line
	7960 3940 7265 3940
Wire Wire Line
	7960 4040 7265 4040
Wire Wire Line
	7960 4140 7265 4140
Wire Wire Line
	7960 1840 7065 1840
Wire Wire Line
	7960 1940 7065 1940
Wire Wire Line
	9460 1840 10235 1840
Wire Wire Line
	9460 2040 10235 2040
Wire Wire Line
	9460 3540 10235 3540
Wire Wire Line
	9460 3740 10235 3740
Wire Wire Line
	7960 3540 7065 3540
Wire Wire Line
	7960 3640 7065 3640
Wire Wire Line
	7415 3740 7960 3740
Wire Wire Line
	7415 975  7415 2040
Wire Wire Line
	7415 2040 7960 2040
Wire Bus Line
	4760 5330 7165 5330
Connection ~ 7415 2040
Connection ~ 7315 2140
Wire Wire Line
	7415 2040 7415 3740
Wire Wire Line
	7315 2140 7315 3840
Connection ~ 7165 5330
Wire Bus Line
	7165 5330 10135 5330
Entry Wire Line
	4660 4330 4760 4430
Entry Wire Line
	4660 4630 4760 4730
Entry Wire Line
	4660 4930 4760 5030
Entry Wire Line
	4660 5230 4760 5330
Text Label 4455 4330 0    60   ~ 0
m4
Text Label 4460 4630 0    60   ~ 0
m5
Text Label 4460 5230 0    60   ~ 0
m7
$Comp
L 4416:4416 U6
U 1 1 5E74C446
P 8710 2140
F 0 "U6" H 8710 2905 50  0000 C CNN
F 1 "4416" H 8710 2814 50  0000 C CNN
F 2 "LittleSixteen:DIP-18_W7.62mm_Socket_LongPads" H 8710 1390 50  0001 C CNN
F 3 "http://pdf.datasheetcatalog.com/datasheet_pdf/texas-instruments/TMS4416-12_to_TMS4416-20.pdf" H 8710 1490 50  0001 C CNN
	1    8710 2140
	1    0    0    -1  
$EndComp
$Comp
L 4416:4416 U5
U 1 1 5E787BCA
P 8710 3840
F 0 "U5" H 8710 4605 50  0000 C CNN
F 1 "4416" H 8710 4514 50  0000 C CNN
F 2 "LittleSixteen:DIP-18_W7.62mm_Socket_LongPads" H 8710 3090 50  0001 C CNN
F 3 "http://pdf.datasheetcatalog.com/datasheet_pdf/texas-instruments/TMS4416-12_to_TMS4416-20.pdf" H 8710 3190 50  0001 C CNN
	1    8710 3840
	1    0    0    -1  
$EndComp
$Comp
L power:GND #PWR0122
U 1 1 5E789256
P 9560 4500
F 0 "#PWR0122" H 9560 4250 50  0001 C CNN
F 1 "GND" H 9565 4327 50  0000 C CNN
F 2 "" H 9560 4500 50  0001 C CNN
F 3 "" H 9560 4500 50  0001 C CNN
	1    9560 4500
	1    0    0    -1  
$EndComp
Wire Wire Line
	9560 3440 9560 4500
Wire Wire Line
	7315 1155 6670 1155
Text GLabel 6670 1155 0    50   Input ~ 0
~RAS
Wire Wire Line
	7415 975  6675 975 
Text GLabel 6675 975  0    50   Input ~ 0
R_~W
Text GLabel 6670 790  0    50   Input ~ 0
~CAS
Wire Wire Line
	9690 790  6670 790 
Wire Wire Line
	9460 1940 9690 1940
Wire Bus Line
	6965 1320 6785 1320
Text GLabel 6785 1320 0    50   Input ~ 0
d[0..7]
$Comp
L power:VCC #PWR0123
U 1 1 5E82E0E5
P 7855 1235
F 0 "#PWR0123" H 7855 1085 50  0001 C CNN
F 1 "VCC" H 7872 1408 50  0000 C CNN
F 2 "" H 7855 1235 50  0001 C CNN
F 3 "" H 7855 1235 50  0001 C CNN
	1    7855 1235
	1    0    0    -1  
$EndComp
Wire Wire Line
	7855 1235 7855 2540
Wire Wire Line
	7855 2540 7960 2540
$Comp
L power:GND #PWR0125
U 1 1 5E84F3D5
P 9560 2735
F 0 "#PWR0125" H 9560 2485 50  0001 C CNN
F 1 "GND" H 9565 2562 50  0000 C CNN
F 2 "" H 9560 2735 50  0001 C CNN
F 3 "" H 9560 2735 50  0001 C CNN
	1    9560 2735
	1    0    0    -1  
$EndComp
Wire Wire Line
	9560 2735 9560 1740
Wire Bus Line
	6965 1320 10335 1320
Connection ~ 6965 1320
Wire Wire Line
	9690 790  9690 1940
Wire Wire Line
	9690 1940 9690 3640
Wire Wire Line
	9690 3640 9460 3640
Connection ~ 9690 1940
Wire Wire Line
	9460 3440 9560 3440
Wire Wire Line
	7960 3440 7735 3440
Wire Wire Line
	7855 3185 7855 4240
$Comp
L power:VCC #PWR0126
U 1 1 5E8FC851
P 7855 3185
F 0 "#PWR0126" H 7855 3035 50  0001 C CNN
F 1 "VCC" H 7872 3358 50  0000 C CNN
F 2 "" H 7855 3185 50  0001 C CNN
F 3 "" H 7855 3185 50  0001 C CNN
	1    7855 3185
	1    0    0    -1  
$EndComp
Wire Wire Line
	7855 4240 7960 4240
Entry Wire Line
	10235 3540 10335 3440
Wire Wire Line
	4390 1590 4660 1590
Wire Wire Line
	4390 1890 4660 1890
Wire Wire Line
	4390 4330 4660 4330
Wire Wire Line
	4390 4630 4660 4630
Wire Wire Line
	4390 4930 4660 4930
Wire Wire Line
	4390 5230 4660 5230
Text Label 4460 4930 0    60   ~ 0
m6
$Comp
L 74ls157:74LS157 U7
U 2 1 5EA2906C
P 3005 7010
F 0 "U7" H 3235 7081 50  0000 L CNN
F 1 "74LS257" H 3235 6990 50  0000 L CNN
F 2 "LittleSixteen:DIP-16_W7.62mm_Socket_LongPads" H 3005 7010 50  0001 C CNN
F 3 "" H 3005 7010 50  0001 C CNN
	2    3005 7010
	1    0    0    -1  
$EndComp
$Comp
L 74ls157:74LS157 U8
U 2 1 5EA2A6DF
P 4510 7010
F 0 "U8" H 4740 7081 50  0000 L CNN
F 1 "74LS257" H 4740 6990 50  0000 L CNN
F 2 "LittleSixteen:DIP-16_W7.62mm_Socket_LongPads" H 4510 7010 50  0001 C CNN
F 3 "" H 4510 7010 50  0001 C CNN
	2    4510 7010
	1    0    0    -1  
$EndComp
$Comp
L Device:C C10
U 1 1 5EA3B958
P 5265 6985
F 0 "C10" H 5380 7031 50  0000 L CNN
F 1 "100n" H 5380 6940 50  0000 L CNN
F 2 "Capacitor_THT:C_Disc_D8.0mm_W2.5mm_P5.00mm" H 5303 6835 50  0001 C CNN
F 3 "~" H 5265 6985 50  0001 C CNN
	1    5265 6985
	1    0    0    -1  
$EndComp
Wire Wire Line
	4510 6560 4510 6525
Wire Wire Line
	4510 6525 4885 6525
Wire Wire Line
	5265 6525 5265 6835
Wire Wire Line
	5265 7135 5265 7455
Wire Wire Line
	5265 7455 4885 7455
Wire Wire Line
	4510 7455 4510 7410
Wire Wire Line
	4885 7455 4885 7530
$Comp
L power:GND #PWR0135
U 1 1 5EA452B0
P 4885 7530
F 0 "#PWR0135" H 4885 7280 50  0001 C CNN
F 1 "GND" H 4890 7357 50  0000 C CNN
F 2 "" H 4885 7530 50  0001 C CNN
F 3 "" H 4885 7530 50  0001 C CNN
	1    4885 7530
	1    0    0    -1  
$EndComp
Connection ~ 4885 7455
Wire Wire Line
	4885 7455 4510 7455
Wire Wire Line
	4885 6450 4885 6525
$Comp
L power:VCC #PWR0136
U 1 1 5EA4A17E
P 4885 6450
F 0 "#PWR0136" H 4885 6300 50  0001 C CNN
F 1 "VCC" H 4902 6623 50  0000 C CNN
F 2 "" H 4885 6450 50  0001 C CNN
F 3 "" H 4885 6450 50  0001 C CNN
	1    4885 6450
	1    0    0    -1  
$EndComp
Connection ~ 4885 6525
Wire Wire Line
	4885 6525 5265 6525
Text Notes 3610 7660 0    50   ~ 0
Additional\ndecoupling cap
Wire Wire Line
	6400 7140 6400 7215
Wire Wire Line
	6400 6765 6400 6840
$Comp
L power:GND #PWR0137
U 1 1 5EA7A77F
P 6400 7215
F 0 "#PWR0137" H 6400 6965 50  0001 C CNN
F 1 "GND" H 6405 7042 50  0000 C CNN
F 2 "" H 6400 7215 50  0001 C CNN
F 3 "" H 6400 7215 50  0001 C CNN
	1    6400 7215
	1    0    0    -1  
$EndComp
$Comp
L power:VCC #PWR0138
U 1 1 5EA7A789
P 6400 6765
F 0 "#PWR0138" H 6400 6615 50  0001 C CNN
F 1 "VCC" H 6417 6938 50  0000 C CNN
F 2 "" H 6400 6765 50  0001 C CNN
F 3 "" H 6400 6765 50  0001 C CNN
	1    6400 6765
	1    0    0    -1  
$EndComp
$Comp
L Device:C C8
U 1 1 5EA8BF73
P 6400 6990
F 0 "C8" H 6515 7036 50  0000 L CNN
F 1 "220n" H 6515 6945 50  0000 L CNN
F 2 "Capacitor_THT:C_Disc_D8.0mm_W2.5mm_P5.00mm" H 6438 6840 50  0001 C CNN
F 3 "~" H 6400 6990 50  0001 C CNN
	1    6400 6990
	1    0    0    -1  
$EndComp
Wire Wire Line
	5850 7140 5850 7215
Wire Wire Line
	5850 6765 5850 6840
$Comp
L power:GND #PWR0139
U 1 1 5EAAE0BE
P 5850 7215
F 0 "#PWR0139" H 5850 6965 50  0001 C CNN
F 1 "GND" H 5855 7042 50  0000 C CNN
F 2 "" H 5850 7215 50  0001 C CNN
F 3 "" H 5850 7215 50  0001 C CNN
	1    5850 7215
	1    0    0    -1  
$EndComp
$Comp
L power:VCC #PWR0140
U 1 1 5EAAE0C8
P 5850 6765
F 0 "#PWR0140" H 5850 6615 50  0001 C CNN
F 1 "VCC" H 5867 6938 50  0000 C CNN
F 2 "" H 5850 6765 50  0001 C CNN
F 3 "" H 5850 6765 50  0001 C CNN
	1    5850 6765
	1    0    0    -1  
$EndComp
$Comp
L Device:C C7
U 1 1 5EAAE0D2
P 5850 6990
F 0 "C7" H 5965 7036 50  0000 L CNN
F 1 "220n" H 5965 6945 50  0000 L CNN
F 2 "Capacitor_THT:C_Disc_D8.0mm_W2.5mm_P5.00mm" H 5888 6840 50  0001 C CNN
F 3 "~" H 5850 6990 50  0001 C CNN
	1    5850 6990
	1    0    0    -1  
$EndComp
Text Label 4460 2190 0    60   ~ 0
m2
Wire Wire Line
	4390 2190 4660 2190
Text Label 4460 2490 0    60   ~ 0
m3
Wire Wire Line
	4390 2490 4660 2490
Entry Wire Line
	2010 1590 2110 1690
Text Label 2310 1690 0    60   ~ 0
a0
Wire Wire Line
	2110 1690 2920 1690
Text Label 2310 2590 0    60   ~ 0
a3
Text Label 2310 2490 0    60   ~ 0
a10
Text Label 2310 2290 0    60   ~ 0
a2
Text Label 2310 2190 0    60   ~ 0
a9
Text Label 2310 1990 0    60   ~ 0
a1
Text Label 2310 1890 0    60   ~ 0
a8
Entry Wire Line
	2010 2490 2110 2590
Entry Wire Line
	2010 2390 2110 2490
Entry Wire Line
	2010 2190 2110 2290
Entry Wire Line
	2010 2090 2110 2190
Entry Wire Line
	2010 1890 2110 1990
Entry Wire Line
	2010 1790 2110 1890
Wire Wire Line
	2110 1890 2920 1890
Wire Wire Line
	2110 1990 2920 1990
Wire Wire Line
	2110 2190 2920 2190
Wire Wire Line
	2110 2290 2920 2290
Wire Wire Line
	2110 2590 2920 2590
Wire Wire Line
	2110 2490 2920 2490
Wire Wire Line
	1765 2790 1865 2790
Wire Wire Line
	2920 1590 2765 1590
Wire Wire Line
	2765 1590 2765 1230
Text GLabel 1765 2790 0    50   Input ~ 0
MUX
Wire Bus Line
	2010 1260 1795 1260
Text GLabel 1795 1260 0    50   Input ~ 0
a[0..15]
Entry Wire Line
	2010 4330 2110 4430
Text Label 2310 4430 0    60   ~ 0
a4
Wire Wire Line
	2110 4430 2920 4430
Text Label 2310 5330 0    60   ~ 0
a7
Text Label 2310 4930 0    60   ~ 0
a13
Text Label 2310 5030 0    60   ~ 0
a6
Text Label 2310 4730 0    60   ~ 0
a5
Text Label 2310 4630 0    60   ~ 0
a12
Entry Wire Line
	2010 5230 2110 5330
Entry Wire Line
	2010 4830 2110 4930
Entry Wire Line
	2010 4930 2110 5030
Entry Wire Line
	2010 4630 2110 4730
Entry Wire Line
	2010 4530 2110 4630
Wire Wire Line
	2110 4630 2920 4630
Wire Wire Line
	2110 4730 2920 4730
Wire Wire Line
	2110 5030 2920 5030
Wire Wire Line
	2110 5330 2920 5330
$Comp
L power:VCC #PWR0120
U 1 1 5E710070
P 3030 3890
F 0 "#PWR0120" H 3030 3740 50  0001 C CNN
F 1 "VCC" H 3047 4063 50  0000 C CNN
F 2 "" H 3030 3890 50  0001 C CNN
F 3 "" H 3030 3890 50  0001 C CNN
	1    3030 3890
	1    0    0    -1  
$EndComp
Entry Wire Line
	2010 4230 2110 4330
Text Label 2310 4330 0    60   ~ 0
a11
Wire Wire Line
	2110 4330 2920 4330
$Comp
L 74ls157:74LS157 U8
U 1 1 5E9C487A
P 3420 4930
F 0 "U8" H 3420 5680 50  0000 C CNN
F 1 "74LS257" H 3420 4060 50  0000 C CNN
F 2 "LittleSixteen:DIP-16_W7.62mm_Socket_LongPads" H 3420 4930 50  0001 C CNN
F 3 "" H 3420 4930 50  0001 C CNN
	1    3420 4930
	1    0    0    -1  
$EndComp
Wire Wire Line
	2765 5230 2920 5230
Wire Wire Line
	2110 4930 2920 4930
Wire Wire Line
	2765 3970 2765 5230
Wire Wire Line
	1865 2790 1865 5530
Wire Wire Line
	1865 5530 2920 5530
Connection ~ 1865 2790
Wire Wire Line
	1865 2790 2920 2790
$Comp
L 74ls157:74LS157 U7
U 1 1 5EA19058
P 3420 2190
F 0 "U7" H 3420 2940 50  0000 C CNN
F 1 "74LS257" H 3420 1320 50  0000 C CNN
F 2 "LittleSixteen:DIP-16_W7.62mm_Socket_LongPads" H 3420 2190 50  0001 C CNN
F 3 "" H 3420 2190 50  0001 C CNN
	1    3420 2190
	1    0    0    -1  
$EndComp
Text Notes 2155 3555 0    50   ~ 0
U7 and U8 can either be 74x157 or 74x257,\nsince they are permanently enabled
Wire Wire Line
	3920 5230 3990 5230
Wire Wire Line
	3920 4330 3990 4330
Wire Wire Line
	3920 4630 3990 4630
Wire Wire Line
	3920 4930 3990 4930
Wire Wire Line
	3920 2490 3990 2490
Wire Wire Line
	3920 1590 3990 1590
Wire Wire Line
	3920 2190 3990 2190
Wire Wire Line
	3920 1890 3990 1890
$Comp
L rp3:RPack4_RP3 RP3
U 1 1 5E2F7E53
P 4190 2050
F 0 "RP3" V 3513 2050 50  0000 C CNN
F 1 "68" V 3604 2050 50  0000 C CNN
F 2 "Resistor_THT:R_Array_SIP8" V 4255 2050 50  0001 C CNN
F 3 "" H 4330 2050 50  0001 C CNN
F 4 "Independent" H 4190 2050 50  0001 C CNN "Notes"
	1    4190 2050
	0    1    1    0   
$EndComp
$Comp
L rp4:RPack4_RP4 RP4
U 1 1 5E55EE90
P 4190 4790
F 0 "RP4" V 3513 4790 50  0000 C CNN
F 1 "68" V 3604 4790 50  0000 C CNN
F 2 "Resistor_THT:R_Array_SIP8" V 4255 4790 50  0001 C CNN
F 3 "" H 4330 4790 50  0001 C CNN
F 4 "Independent" H 4190 4790 50  0001 C CNN "Notes"
	1    4190 4790
	0    1    1    0   
$EndComp
Text Notes 4360 3775 1    50   ~ 0
Yes, RP3/4 have this\nweird pin numbering,\nmost likely in order to\nmake routing easier
$Comp
L Device:C C92
U 1 1 611A31E9
P 3760 6985
F 0 "C92" H 3875 7031 50  0000 L CNN
F 1 "100n" H 3875 6940 50  0000 L CNN
F 2 "Capacitor_THT:C_Disc_D8.0mm_W2.5mm_P5.00mm" H 3798 6835 50  0001 C CNN
F 3 "~" H 3760 6985 50  0001 C CNN
	1    3760 6985
	1    0    0    -1  
$EndComp
Wire Wire Line
	3005 6560 3005 6525
Wire Wire Line
	3005 6525 3380 6525
Wire Wire Line
	3760 6525 3760 6835
Wire Wire Line
	3760 7135 3760 7455
Wire Wire Line
	3760 7455 3380 7455
Wire Wire Line
	3005 7455 3005 7410
Wire Wire Line
	3380 7455 3380 7530
$Comp
L power:GND #PWR0162
U 1 1 611A31FA
P 3380 7530
F 0 "#PWR0162" H 3380 7280 50  0001 C CNN
F 1 "GND" H 3385 7357 50  0000 C CNN
F 2 "" H 3380 7530 50  0001 C CNN
F 3 "" H 3380 7530 50  0001 C CNN
	1    3380 7530
	1    0    0    -1  
$EndComp
Connection ~ 3380 7455
Wire Wire Line
	3380 7455 3005 7455
Wire Wire Line
	3380 6450 3380 6525
$Comp
L power:VCC #PWR0163
U 1 1 611A3207
P 3380 6450
F 0 "#PWR0163" H 3380 6300 50  0001 C CNN
F 1 "VCC" H 3397 6623 50  0000 C CNN
F 2 "" H 3380 6450 50  0001 C CNN
F 3 "" H 3380 6450 50  0001 C CNN
	1    3380 6450
	1    0    0    -1  
$EndComp
Connection ~ 3380 6525
Wire Wire Line
	3380 6525 3760 6525
$Comp
L Connector:Conn_01x03_Male JP4
U 1 1 61451C3E
P 2765 3770
F 0 "JP4" V 2827 3582 50  0000 R CNN
F 1 "JP_RAMSIZE2" V 2918 3582 50  0000 R CNN
F 2 "Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical" H 2765 3770 50  0001 C CNN
F 3 "~" H 2765 3770 50  0001 C CNN
	1    2765 3770
	0    1    1    0   
$EndComp
Wire Wire Line
	2865 3970 2865 4100
Wire Wire Line
	2865 4100 3030 4100
Wire Wire Line
	3030 4100 3030 3890
Wire Wire Line
	2665 3970 2665 4100
Wire Wire Line
	2665 4100 2110 4100
Entry Wire Line
	2010 4000 2110 4100
Text Label 2310 4100 0    60   ~ 0
a14
$Comp
L power:VCC #PWR0118
U 1 1 6147AF8D
P 3030 1150
F 0 "#PWR0118" H 3030 1000 50  0001 C CNN
F 1 "VCC" H 3047 1323 50  0000 C CNN
F 2 "" H 3030 1150 50  0001 C CNN
F 3 "" H 3030 1150 50  0001 C CNN
	1    3030 1150
	1    0    0    -1  
$EndComp
$Comp
L Connector:Conn_01x03_Male JP3
U 1 1 6147B280
P 2765 1030
F 0 "JP3" V 2827 842 50  0000 R CNN
F 1 "JP_RAMSIZE1" V 2918 842 50  0000 R CNN
F 2 "Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical" H 2765 1030 50  0001 C CNN
F 3 "~" H 2765 1030 50  0001 C CNN
	1    2765 1030
	0    1    1    0   
$EndComp
Wire Wire Line
	2865 1230 2865 1360
Wire Wire Line
	2865 1360 3030 1360
Wire Wire Line
	3030 1360 3030 1150
Wire Wire Line
	2665 1230 2665 1360
Wire Wire Line
	2665 1360 2110 1360
Entry Wire Line
	2010 1260 2110 1360
Text Label 2310 1360 0    60   ~ 0
a15
Text Notes 3175 1230 0    50   ~ 0
JP3/4 are a 16kB/64kB\nRAM Switch Mod. Use\n4464 chips instead of 4416.
Text GLabel 5445 1540 0    50   Input ~ 0
RAMEN
$Comp
L 74xx:74LS02 U?
U 4 1 618ABE98
P 6015 1640
AR Path="/5EE7AAEB/618ABE98" Ref="U?"  Part="4" 
AR Path="/5EACE220/618ABE98" Ref="U?"  Part="4" 
AR Path="/5E4A465A/618ABE98" Ref="U12"  Part="4" 
F 0 "U12" H 6015 1965 50  0000 C CNN
F 1 "74LS02" H 6015 1874 50  0000 C CNN
F 2 "LittleSixteen:DIP-14_W7.62mm_Socket_LongPads" H 6015 1640 50  0001 C CNN
F 3 "http://www.ti.com/lit/gpn/sn74ls02" H 6015 1640 50  0001 C CNN
	4    6015 1640
	1    0    0    -1  
$EndComp
Wire Wire Line
	5445 1540 5615 1540
Wire Wire Line
	5615 1540 5615 1740
Wire Wire Line
	5615 1740 5715 1740
Connection ~ 5615 1540
Wire Wire Line
	5615 1540 5715 1540
$Comp
L Device:R R99
U 1 1 61920791
P 5615 1200
F 0 "R99" H 5685 1246 50  0000 L CNN
F 1 "10k" H 5685 1155 50  0000 L CNN
F 2 "Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P5.08mm_Vertical" V 5545 1200 50  0001 C CNN
F 3 "~" H 5615 1200 50  0001 C CNN
	1    5615 1200
	1    0    0    -1  
$EndComp
Wire Wire Line
	5615 1350 5615 1540
$Comp
L power:VCC #PWR0119
U 1 1 61928882
P 5615 950
F 0 "#PWR0119" H 5615 800 50  0001 C CNN
F 1 "VCC" H 5632 1123 50  0000 C CNN
F 2 "" H 5615 950 50  0001 C CNN
F 3 "" H 5615 950 50  0001 C CNN
	1    5615 950 
	1    0    0    -1  
$EndComp
Wire Wire Line
	5615 950  5615 1050
Text Label 6325 1640 0    50   ~ 0
~ramen
Text Notes 5140 2420 0    50   ~ 0
We make use of a spare gate to fix the\neternal problem of external RAM\nexpansions not working, which is due to\nthe impossibility of disabling the internal\nRAM. This should do it, just ground the Z\npin and the internal RAM will disappear.
Wire Wire Line
	7960 1740 7735 1740
Wire Wire Line
	7735 1740 7735 3440
Wire Wire Line
	7735 1640 7735 1740
Wire Wire Line
	6315 1640 7735 1640
Connection ~ 7735 1740
Wire Wire Line
	2920 2890 2760 2890
Wire Wire Line
	2760 2890 2760 3035
$Comp
L power:GND #PWR0124
U 1 1 61D1A007
P 2760 3035
F 0 "#PWR0124" H 2760 2785 50  0001 C CNN
F 1 "GND" H 2765 2862 50  0000 C CNN
F 2 "" H 2760 3035 50  0001 C CNN
F 3 "" H 2760 3035 50  0001 C CNN
	1    2760 3035
	1    0    0    -1  
$EndComp
Wire Wire Line
	2920 5630 2760 5630
Wire Wire Line
	2760 5630 2760 5775
$Comp
L power:GND #PWR0127
U 1 1 61D1AB2F
P 2760 5775
F 0 "#PWR0127" H 2760 5525 50  0001 C CNN
F 1 "GND" H 2765 5602 50  0000 C CNN
F 2 "" H 2760 5775 50  0001 C CNN
F 3 "" H 2760 5775 50  0001 C CNN
	1    2760 5775
	1    0    0    -1  
$EndComp
Wire Bus Line
	6965 1320 6965 3540
Wire Bus Line
	10335 1320 10335 3645
Wire Bus Line
	7165 2340 7165 5330
Wire Bus Line
	4760 1690 4760 5330
Wire Bus Line
	10135 2240 10135 5330
Wire Bus Line
	2010 1260 2010 5230
$EndSCHEMATC