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 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(a)intellistar.net> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Monday, May 10, 1999 3:02 PM Subject: Re: manuals available I