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Re: [N8VEM-S100:1093] 8T97 Substitutions


I have been busy but I am interested in reconnecting with the project.

Is my initial board of any use now, or have you moved on?

I am still hoping to end up with a working panel as agreed.

I just stopped working after I posted my results and no-one engaged
the project for months.


On Aug 27, 2012, at 1:47 PM, Don Caprio <ilv...@gmail.com> wrote:

Speaking of the Intel 8212. I've only been able to find the 3Mhz version.
Did Intel produce a faster version? I'm looking for a 4Mhz version for use
in the FP mini project.

On 08/20/12 05:37 PM, Richard Cini wrote:
The 8212 is a weird kind of chip because it's a multi-function chip designed to eliminate 2-3-4 different chips in an 8008/8080/8085 system. It includes an 8-bit D-type latch, address selection logic and an interrupt generator. The data book I have shows it as being used as a status latch for the 8080, a standard gated buffer, a bi-directional buss driver (with two chips), an interrupting input port, a port to jam a RST instruction into the data buss during an interrupt acknowledge cycle, an output port, and an address buss latch. So, I guess it depends on the circuit whether you can replace it with another chip or not.

There was also an 8228 system controller chip which performed a similar buss status latch using WR, DBIN and HLDA plus the data buss to provide a bi-directional data buss driver and control signals (INTA, MEMR/W, IOR/W). There is a 6-part article on my Web site from Popular Electronics (9/81) that shows this setup.


Rich Cini
Collector of Classic Computers
Build Master and lead engineer, Altair32 Emulator

From: Don Caprio <cap...@uxpro.com>
Reply-To: <n8vem...@googlegroups.com>
Date: Monday, August 20, 2012 8:12 PM
To: <n8vem...@googlegroups.com>
Subject: Re: [N8VEM-S100:1064] 8T97 Substitutions

Thanks Rich. Any ideas for Intel 8212 substitutions?

On Mon, Aug 20, 2012 at 4:59 PM, Richard Cini <rich...@verizon.net> wrote:
Don --

        I have used the LS367 as a substitute with no apparent problems.


Rich Cini
Collector of Classic Computers
Build Master and lead engineer, Altair32 Emulator

On 8/20/12 7:54 PM, "Don Caprio" <ilv...@gmail.com> wrote:

>I'm looking for substitutions for IC 8T97 (HEX 3-state buffer/bus driver).
>The 8T97's are expensive (~$5).
>I've seen suggestions that the following are substitutions. Does anyone
>have experience
>with these substations? Are all adequate? Which would be the best choice?
>Jameco has the 74LS367 for $.89 cents, Anchor Electronics $.46, Abra $.39.
>Where is a good source for the Intel 8212? These too run in the $5 for
>Is there a suitable replacement for it as well?

Don Caprio cap...@uxpro.com
(925) 240-UNIX

Don Caprio