Philips made their own VHS mech. before the "Charly Deck" ie.the "Echo deck" this was an "M wrap" machine albeit with Philips' spin on things, (opto interupter for head switching(PG) amongst other things).
As Sideband said they bought in some panasonic " D Decks" but some of these used Philips electronics, I can't be sure if some of these used philips' own heads (it was a long time ago) , they also bought in some Sharp Decks (the one with the two main cams), again they may or may not have used Philips electronics (the front panel ISTR was Philips).
ISTR reading, or being told, they bought in Panasonic's "G mech" these did use Philips heads (at least the ones I repaired), While the development of the "turbo deck" was underway, (because the "charly deck" couldn't use the realtime counter without being "fully laced" and the competitions decks had a half-load position, which the charly deck didn't (later on most decks did away with the half load position anyway).
The charly deck was quite clever in that it only had 3 simple on/off switches on the deck (called COD switches in Philips manuals) or "code switches" and relied heavily on software to control the deck functions, via I2C, which Philips had developed.
These machines were unlike any other as they used Philips own "chipset" and everything was done in software/I2C.
Sideband may elaborate or correct me on this point.
There was not that many engineers in my area that would repair these machines, (they were known locally as "Plastic pigs").
I repaired more than my fair share of these, and didn't find them too bad, once you knew how to do them (PP3 battery
).
I could fit the maintainence/Rack kit in about 20-30 mins most of the time, but sometimes get the odd one which could take most of the day (ones where nothing went right!).
I suppose they were relatively cheap to produce (for the time).
ISTR they could be assembled by machine/automated, but whether this is an "urban myth" or not, I will leave for others (sideband)
This deck underwent loads of modifcations/variations, from memory, DMP, IDM, JDM and KDM variants. Where very few bits, other than the repair kits were interchangable.
Sorry for the length of this post.
Cheers,
Baz