The theory that says the mark of the beast is a computer chip has been around since the 80's , I think.
I reject the theory because the scripture was given for all generations and the only reason for that interpretation is modern technology and people speculating. I don't think that the scripture was given to only provide meaning for our generation. People who read that a 1000 years ago should be able to get something out of it too. So I find it is to be unlikely that the only meaningful interpretation would only be possible in the last fifty years.
Also worth noting , some Greek manuscripts render the number 616 and not 666 as noted in the NRSV version of the Bible.
Some of the other theories which have also used Gematria as a basis for their interpretation have suggested Nero , the Pope and Muhammed. They do this by adding the number values of the letters together and obtaining 666. If a person connects it with the woman of Revelation 17 drunk on the blood of the saints, one could apply that to all three of the choices. Nero and the Roman empire are well known for their persecution of the Christians and the blood that they spilt. But so is the Islamic empire and so is the Roman Catholic Church. All three waged war on the saints and killed countless Christians over the centuries. Maybe they are all a little bit right because the scriptures say one place that there are many antichrists.
1 John 2:18
So perhaps any system or person who opposes the anointed ones are the anti Christs , plural since Christ means anointed one and Christians are the anointed ones, plural. So that the antichrists are the followers of The Devil who is the ultimate anti Christ. I think anyone who is killing and opposing true Christians could be considered an antichrist. SO we really cannot rule out Islam and Nero as at least being antichrists in their generation.
The term antichrist literally means one who opposes Christ. Or even more literally , one who opposes the anointed one. Anytime the anointing of God manifests ion this earth , the spirit of antichrist rises up to oppose it. Of course as we are in the last days and as we approach the end , the battle intensifies and the antichrist spirit manifests even more.
Based upon that , I do believe that while these other examples may have been antichrists plural as in operating in the spirit of antichrist , I also believe that the ultimate unveiling of the antichrist will come in the last generation before the return of Christ to this earth. So perhaps the ultimate unveiling could involve a computer chip , but I still have my doubts.