1.1 --- a/CPU_ROM_KBD.sch Sat Feb 12 16:42:18 2022 +0100
1.2 +++ b/CPU_ROM_KBD.sch Sat Feb 12 19:35:41 2022 +0100
1.3 @@ -556,7 +556,7 @@
1.4 5900 3800 6600 3800
1.5 Wire Wire Line
1.6 5900 3900 6600 3900
1.7 -Text GLabel 8650 3300 2 50 Input ~ 0
1.8 +Text GLabel 9400 3300 2 50 Input ~ 0
1.9 ~NMI
1.10 Text GLabel 6200 4200 2 50 Input ~ 0
1.11 ~IRQ
1.12 @@ -581,7 +581,7 @@
1.13 ROM
1.14 Text GLabel 7500 900 2 50 Output ~ 0
1.15 CAPS_LOCK
1.16 -Text Notes 6800 3200 0 50 ~ 0
1.17 +Text Notes 6800 3100 0 50 ~ 0
1.18 Issue 6 boards tend to have\nIC18 (74LS08) fitted for some\nkind of buffering for ~NMI\nand for PHI_OUT.\n\nLK8 is made to disable buffering via IC18 for ~NMI.\nLK9 is made to disable buffering via IC18 for PHI_OUT.\n\nThese buffers were introduced for the Aberdeen ULA,\nand are superfluous for the Ferranti ULA.\nSee the "Acorn Information - Volume 1" document.\n
1.19 $Comp
1.20 L 74xx:74LS08 IC18
1.21 @@ -683,22 +683,22 @@
1.22 $Comp
1.23 L 74xx:74LS08 IC18
1.24 U 5 1 61FA23D2
1.25 -P 9300 3100
1.26 -F 0 "IC18" H 9530 3146 50 0000 L CNN
1.27 -F 1 "74LS08" H 9530 3055 50 0000 L CNN
1.28 -F 2 "" H 9300 3100 50 0001 C CNN
1.29 -F 3 "http://www.ti.com/lit/gpn/sn74LS08" H 9300 3100 50 0001 C CNN
1.30 - 5 9300 3100
1.31 +P 10500 3100
1.32 +F 0 "IC18" H 10730 3146 50 0000 L CNN
1.33 +F 1 "74LS08" H 10730 3055 50 0000 L CNN
1.34 +F 2 "" H 10500 3100 50 0001 C CNN
1.35 +F 3 "http://www.ti.com/lit/gpn/sn74LS08" H 10500 3100 50 0001 C CNN
1.36 + 5 10500 3100
1.37 1 0 0 -1
1.38 $EndComp
1.39 -Text GLabel 9300 2500 1 50 Input ~ 0
1.40 +Text GLabel 10500 2500 1 50 Input ~ 0
1.41 5V
1.42 Wire Wire Line
1.43 - 9300 2500 9300 2600
1.44 -Text GLabel 9300 3700 3 50 Input ~ 0
1.45 + 10500 2500 10500 2600
1.46 +Text GLabel 10500 3700 3 50 Input ~ 0
1.47 0V
1.48 Wire Wire Line
1.49 - 9300 3700 9300 3600
1.50 + 10500 3700 10500 3600
1.51 Text Label 6700 1100 2 50 ~ 0
1.52 KBD[0..3]
1.53 Text Label 6700 1500 2 50 ~ 0
1.54 @@ -751,7 +751,7 @@
1.55 -1 0 0 -1
1.56 $EndComp
1.57 Wire Wire Line
1.58 - 8650 3300 8500 3300
1.59 + 9400 3300 9200 3300
1.60 $Comp
1.61 L power:PWR_FLAG #FLG0108
1.62 U 1 1 62024ADF
1.63 @@ -771,18 +771,33 @@
1.64 Connection ~ 8500 3300
1.65 Wire Wire Line
1.66 8200 4000 8500 4000
1.67 +$Comp
1.68 +L Device:D D99
1.69 +U 1 1 620A4697
1.70 +P 9050 3300
1.71 +F 0 "D99" H 9050 3516 50 0000 C CNN
1.72 +F 1 "D" H 9050 3425 50 0000 C CNN
1.73 +F 2 "" H 9050 3300 50 0001 C CNN
1.74 +F 3 "~" H 9050 3300 50 0001 C CNN
1.75 + 1 9050 3300
1.76 + 1 0 0 -1
1.77 +$EndComp
1.78 +Wire Wire Line
1.79 + 8900 3300 8500 3300
1.80 Wire Bus Line
1.81 - 2200 1500 6800 1500
1.82 + 4400 1600 4400 4500
1.83 +Wire Bus Line
1.84 + 2100 1600 2100 4200
1.85 Wire Bus Line
1.86 - 2000 1100 2000 2800
1.87 + 2500 1600 2500 4500
1.88 +Wire Bus Line
1.89 + 4000 3800 4000 6100
1.90 Wire Bus Line
1.91 6700 3300 6700 6100
1.92 Wire Bus Line
1.93 - 4000 3800 4000 6100
1.94 -Wire Bus Line
1.95 - 2500 1600 2500 4500
1.96 + 2000 1100 2000 2800
1.97 Wire Bus Line
1.98 - 2100 1600 2100 4200
1.99 -Wire Bus Line
1.100 - 4400 1600 4400 4500
1.101 + 2200 1500 6800 1500
1.102 +Text Notes 8900 3600 0 50 ~ 0
1.103 +Diode added to satisfy KiCad\nelectrical rules check.
1.104 $EndSCHEMATC