The fine print:
Some channels are viewable only with the use of Time Warner Cable-issued digital Set-Top Box; some other channels are viewable only with a TWC-issued digital Set-Top Box, Digital Adapter or CableCARD™-equipped Unidirectional Digital Cable Product (“UDCP”). Channels 100 and above require Time Warner Cable issued digital Set-Top Box, Digital Adapter or CableCARD™-equipped Unidirectional Digital Cable Product (“UDCP”), or a QAM tuner.
Otherwise it'd be 'free'; you're talking about a black box and asking how to decrypt intentionally encrypted signals; the only reason these "set top boxes" exist these days: muney.
All analog devices will need some sort of digital device to tune a digital signal. If a device such as what you want exists, I'd assume it to be a multi thousand dollar item (and quite possibly illegal to sell or use in the US); just rent the boxes from the company.
A universal remote (and all its accompanying headaches) is as best as you're going to get I think.
Digital Adapters do not support channels in the Preferred TV plan, the on-screen guide, or other interactive features. You can find your local channel lineup, which indicates channels not available with Digital Adapters, by clicking on the blue "Download PDF" link on the Channel Finder page.
I need a method to allow a DVR/VCR to work with only a digital signal from TWC.
I would assume that without a Digital Adapter, all you will get (on a digitally tuned television/DVR) is your local 'broadcast' programing. Note, I haven't hooked up a TV in a long time. They might have the local channels on lock-down now too: (but not if you have a QAM*)
"I have found many channels still being broadcast with a 10$ converter that was available just prior to the change. After moving last year I have no signal from these boxes." –Ed Beal
*Or buy a device with a QAM Tuner (to receive free local channels without a box, in conjunction with your paid subscription): How to get 'free' HD with a QAM tuner –Cnet
Many cable providers offer few or no details about unencrypted QAM channels. It is also common for cable providers to falsely insist that a set top box from the cable company is required to watch all digital cable channels, including unencrypted channels, even though QAM channels may be distributed via their system. QAM channels may move without notification and some channels may have strange numbering schemes. –Wiki, QAM television
So, a DVR/VCR with a QAM tuner will work with the digital signal from TWC but it will only provide you with the QAM channels. Again, the name of the game is muney.