summaryrefslogtreecommitdiffstatshomepage
path: root/scripts/src
diff options
context:
space:
mode:
author Vas Crabb <vas@vastheman.com>2017-05-27 18:44:23 +1000
committer Vas Crabb <vas@vastheman.com>2017-05-27 18:44:23 +1000
commit2d4ba2471d86555562870973bd456c8dc2581d33 (patch)
tree1e9ba23de32b657e045e3f116fea17fba96d54c4 /scripts/src
parent95b2aa3dc30776e08c77f1707d5ce8d5af90c1b7 (diff)
netlist: add a crude TTL schmitt trigger model and hook up in 1B11142
sound board, completing the tromba circuit (nw) I'm not sure whether the model works properly or not, but in the circuit where it's used, I don't think it can work properly with the current TTL output model. A capacitor is charged by the Q output of a 74LS74 flipflop (U3A) until the voltage passes the Schmitt trigger's threshold, causing it to reset the flipflop. However, the positive trigger voltage of the Schmitt trigger is 1.6V, but our TTL output model has a high output voltage of 1.0V (see nl_base.cpp:89). I realise the simplified model of TTL logic with high impedance inputs and outputs behaving as though thery're loaded is convenient and fast to simulate, but it's not detailed enough for applications like this where 7400-series chips are used in analog circuitry. This is what held me up last time I tried adding a netlist for this sound board.
Diffstat (limited to 'scripts/src')
-rw-r--r--scripts/src/netlist.lua2
1 files changed, 2 insertions, 0 deletions
diff --git a/scripts/src/netlist.lua b/scripts/src/netlist.lua
index d8238e49246..c15e7bc89fd 100644
--- a/scripts/src/netlist.lua
+++ b/scripts/src/netlist.lua
@@ -192,6 +192,8 @@ project "netlist"
MAME_DIR .. "src/lib/netlist/devices/nld_r2r_dac.h",
MAME_DIR .. "src/lib/netlist/devices/nld_tristate.cpp",
MAME_DIR .. "src/lib/netlist/devices/nld_tristate.h",
+ MAME_DIR .. "src/lib/netlist/devices/nld_schmitt.cpp",
+ MAME_DIR .. "src/lib/netlist/devices/nld_schmitt.h",
MAME_DIR .. "src/lib/netlist/devices/nld_legacy.cpp",
MAME_DIR .. "src/lib/netlist/devices/nld_legacy.h",
MAME_DIR .. "src/lib/netlist/devices/net_lib.cpp",