There is a 4201 by national semi on ebay. I bought a 4201 recently for around $10. I'm mostly looking for a 4040. I have a 4289, three 4002-1s and two 4002-2s. I'd like to setup the 4289 such that I have a boot ROM and then shadow it into RAM. I'd then disable the ROM and run on RAM only. The 4040 is a lot easier to setup for both write and read from the RAM. I also have an extra 4004 but it is an early zebra. I'd like to hang on to it. Dwight
________________________________________ From: cctalk <cctalk-boun...@classiccmp.org> on behalf of Paul Birkel <pbir...@gmail.com> Sent: Saturday, March 19, 2016 11:40 AM To: 'General Discussion: On-Topic and Off-Topic Posts' Subject: RE: Code listings for the I4004 or I4040 -----Original Message----- From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Brent Hilpert Sent: Friday, March 18, 2016 5:41 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Code listings for the I4004 or I4040 ..... I had a failed 4201 chip (clock gen), it would be nice to come across a replacement, but solved the problem with a substitute made from 3 CMOS chips. ----- Brent: Could you share your CMOS circuit design for a 4201 substitute? THX!
