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author AJR <ajrhacker@users.noreply.github.com>2019-07-10 00:45:06 -0400
committer AJR <ajrhacker@users.noreply.github.com>2019-07-10 00:45:06 -0400
commit0f9281a5237e7387006cf2648726dfa21243c49a (patch)
tree2727f0fab9c711637cc5cf322413b64e055a44f3
parent2cd43e6b7ce0c1fbcad506f33172c3403a923164 (diff)
at_keybc.cpp: Note (nw)
-rw-r--r--src/devices/machine/at_keybc.cpp7
1 files changed, 7 insertions, 0 deletions
diff --git a/src/devices/machine/at_keybc.cpp b/src/devices/machine/at_keybc.cpp
index c6d2e037973..80cea51d4d2 100644
--- a/src/devices/machine/at_keybc.cpp
+++ b/src/devices/machine/at_keybc.cpp
@@ -12,6 +12,13 @@
are no longer implemented, the pin assignments are different, and
interrupt outputs are latched externally using a 74ALS74 at ZM87.
+ Many of the ICs that provide functional compatibility with the AT
+ and/or PS/2 "8042" keyboard controllers do not incorporate actual
+ UPI-41 microcontroller cores. This even applies to some directly
+ equivalent 40-pin DIPs such as the JETkey "Keyboard BIOS" V3.0
+ and V5.0, which were found to be Samsung Electronics ASICs when
+ decapped.
+
PC/AT I/O pin assignments:
P10: NC no connection
P11: NC no connection