4 Nov
2011
4 Nov
'11
3:42 p.m.
On 4 Nov 2011 at 8:38, David Riley wrote:
The common ones that don't have indentical funcionality in 74xx TTL seem
to. For example there's a 74HC4017 10-state counter IIRC. However, when
there is the same functionality but differnet pinouts (e.g 7400 .vs.
4011), there isn't a driect equivalent in 74HCxxx, the TTL pinout takes
precedence. So there is a 74HC00, there isn't a 74HC4011
And there are quite a few 'odd' fucntions in the 4000 series CMOS range
that were not commonly used and never made it into 74HCxxx, My older
Philips 4000 series data book lists an HPIB talker.listner state machine
IC, for example.
And I think (without checking the databooks) that 4000 series will stand
a higher supply voltage thea 74HCxxx
Jameco, also; I've gotten quite a few older
ICs to fix my Defender
boards (particularly 4116 RAM chips, which seem to be hard to find for
less than an arm and a leg each anywhere else, unless I'm looking in
the wrong places) from them. CMOS ICs are in a slightly different
class, but he might be able to get better than scrap for them. I've
very little use for them myself.
Don't a lot of 4000-series ICs have 74HCxxxx equivalents? I've still got a bunch of old 4000-series CMOS from when they
first started
appearing. ISTR that they were very slow, unless one used high
(+15V?) supplies. I think I still have my Solid State Scientific
databook from that time.
I know I have by 4000 series databooks...
They are slow, and thus are not commonly used in classic computers. The
odd oens do turn up, particualrly where speed is not very important but
he function was (IIRC ,the BCD interface for my HP9815 calculator has
some odd 4000 series shift registers in it, there is no direct TTL
equivalent,
The also, of course, turn up where low pawer consuption is important.
-tony