7 Aug
2007
7 Aug
'07
7:51 a.m.
Subject: Re: 8085 vs 8085A
From: "Steven Canning" <cannings at earthlink.net>
Date: Tue, 07 Aug 2007 01:11:07 -0700
To: "General Discussion: On-Topic Posts Only" <cctech at
classiccmp.org>
It was. Supposededly the 8085 was used to proto the intel CMOS process
for the 80C48 and 80C188 and later parts.
Hi,
I was looking through my collection yesterday and was testing out an old
Intel SDK85 system. I noticed the main processor is stamped 8085, which
means this chip is either an 8085 or the "A" was not printed properly and
the chip is really an 8085A.
I have a few 8085 systems and a box of 8085 CPUs. I checked them all and
every one of them is an 8085A. I don't think I have ever seen an 8085,
they've all been 8085A types.
Other than the stamp on the chip, is there anyway I can tell the
difference
between an 8085 and an 8085A? Furthermore, is the
8085 rare, and I should
put the chip away, or is it nothing special?
Why did Intel bring out the 8085A? Were there issues with the 8085?
Seeyuzz
River
There were multiple versions of 8085 microprocessors. The original version
of the 8085 microprocessor without suffix "A" was manufactured by Intel
only, and was very quickly replaced with 8085A containing bug fixes. A few
years after that, around 1980, Intel introduced 8085AH - HMOS version of
8085A. There was also 80C85A - CMOS version of the 8085A. It's not clear if
80C85 was ever manufactured by Intel or not, but it was produced by at least two second source manufacturers - OKI and Tundra
Semiconductor. Tundra
Semiconductor manufactured the fastest 8085 microprocessor running at 8 MHz.
I have a few 8mhz intel 8085AH-2s (16mhz clock crystal) HMOSII, those are
scarce but do exist. Intel did make the 8085AH (HMOSII) at 6mhz as well.
Second source manufacturers: AMD, Mitsubishi, NEC, OKI,
Siemens, Toshiba.
I have parts from all of them. I find the 8085 and Z80 to be good workhorse
8 bitters. Both enjoyed long sales lives.
Allison
Best regards, Steven C.