10 Dec
2010
10 Dec
'10
10:36 a.m.
Hi everyone,
we've had a look inside our IME 122 calculator and discovered that it is
full of SN14xx logic ICs. They are mainly from TI, but there are also some
from Motorola and others. It seems that they have the
same function and
pinout as the SN74xx parts but there must be a difference since
the
machine has quite a lot of SN1401 (the SN7401 is a quad open-collector
NAND), but there are no pullup resistors anywhere!
Some of the types are SN1400, SN1401, SN1474, SN1490; the ALU is made up
of SN1482 and SN1483.
Anyone knows this series? BTW the supply voltage is 5V.
Christian