The terminator on VHS

[Electronic M]

Even if a machine with such ability/defect were to exist you can't slow video tape speed down much(read that as 'a humanly perceivable amount') or color sync will be lost, followed by H and V sync*...Ever watch a selectavision player where the turntable belt was going bad and the screen was monochrome with the screen divided into 3 vert stripes, one tinted red, one green and the other blue (and no other semblence of color)?...I have, and that is what happens when you try to slow down analog play back speed even a tiny amount. Sync pulse timing depends on tape/disc speed being exact, bleep with it and things stop working fast.

*This assumes a CRT TV, if you are using a flat panel set there will be more rapid and complete loss of picture as the digital signal processors are even more finicky about getting correct sync.