manuals available

From: Richard Erlacher <edick_at_idcomm.com>
Date: Mon May 10 19:27:54 1999

That's right. In fact, I have the '81 data book on the floor right here.
The ICM7228 is apparently an 8-digit LED display multiplexer which was not
available in '81. I was hoping it was a different part, more like the CMOS
4534, which is a counter-display-driver. In any case, the information I got
from the Harris site and the Maxim site, per a referral from someone in this
group, seems to correlate with my recollection, such as it is, of what these
devices are.

The 7226 is a 10 MHz frequency counter circuit with LED drivers built in. I
once hooked up the part in a 9-digit application using a fast CMOS BCD
counter as a prescaler rather than the ECL jewel they designed in their
app-note. That makes it almost useful, as it then counts up to 100 MHz in
several modes. Of course, you have to prescale both the inputs in order to
make it work right, but it's a handy little tool if you package it right.
That outrageously large board of Intersil's was pretty impractical except
for the purpose for which it was intended, which was to demostrate how their
porduct works. They didn't make it easy to up the count rate by a decade,
nor did they make signal routing in and out very handy. The switches they
used forced one to mount the board in a large box even though only a small
area was needed for the display and switches. Their eval kit for the 7106
DPM was about as impractical. It got us to buy them, though, didn't it?

Dick

-----Original Message-----
From: Joe <rigdonj_at_intellistar.net>
To: Discussion re-collecting of classic computers
<classiccmp_at_u.washington.edu>
Date: Monday, May 10, 1999 3:02 PM
Subject: Re: manuals available


>Richard,
>
> I have a couple of old Intersil Evaluation kits and the manuals list all
>of the devices available in 1981 but don't list a 7228. Are you sure it's
>not a 7226? or else it's newer than 1981.
>
> Joe
>
>At 03:46 PM 5/8/99 -0600, you wrote:
>>I've run into Intersil's ICM7228 once again and find my data book doesn't
>>cover that number. It's date coded '87, so It's probably in the last book
I
>>got from Intersil before they were acquired by GE.
>>
>>Has anyone got a complete sheet on this part? I believe it is a
>>multi-decade counter/display driver, or maybe just a display driver.
>>
>>thanx
>>
>>Dick
>>
>>
>
Received on Mon May 10 1999 - 19:27:54 BST