29 Jan
2011
29 Jan
'11
4:20 p.m.
On 2011 Jan 29, at 12:22 PM, Eric Smith wrote:
Tim Shoppa wrote:
I first saw the CMOS Macrologic ICs (347xx) in the Fairchild 1975 CMOS
databook, where the info is presented as "PRELIMINARY (products planned
for 1975)".
I wasn't aware of the TTL versions until you mentioned them, but I see
now they are listed briefly in the 1975 full-line catalog (94xx
numbers).
Fairchild had the hybrid DTL SH8080 ("4-bit Arithmetic Unit" - 4-bit
adder and accumulator/register) in 1966.
There were many bitslice families out there that
never saw wide use
or maybe only existed in databooks. After the 2901 everyone tried
to jump in. The MC14500B at least was obviously not a 2901 clone :-)
The Am2901 is an improved clone of the MMI 6701! AMD and Raytheon
succeeded in getting the 2901 into mass production before MMI did that
with the 6701, reportedly because MMI had a lot of technical issues
early on. The Fairchild Macrologic parts also appear to have been
inspired by the MMI parts, and by Fairchild's 3800 MOS 8-bit ALU from
1969. The TTL versions of the Fairchild Macrologic parts might have
even shipped prior to the Am2901, though I can't find definitive
information on that. The CMOS Macrologic parts probably shipped after
the Am2901.