Dial tone first payphone controller

[Kimball321]

Ever since I got my Western Electric Single slot payphone I have wondering how to make a dial tone first pay phone controller.  All of the pay phone controllers that I have seen are either coin first or post pay.  Because my single slot is a 1D2 I don't think it can even operate in either of these modes anyways.  So dose anyone have any suggestions on how to create a controller that dose the following,

1. Has dial tone when hand set is picked up
2. Allows calls to "free" numbers (911 toll free) without a coin deposit
3. Allows the payphone's totalizer or what ever it is a 1D2 uses (I know where it is, its some little switches on the back of the chassis board just don't know what to call it) to operate so that the correct amount of money must be inserted
4. Plays a recording when a "non free" call is dialed without a deposit
5. Collects coins on a call that's completed and returns them on calls that are not complete. Also did traditional line controlled pay phones collect money right away on answer or when the phone was hanged up?  Too young to really remember telco pay phones my self so which ever method they used I would want to recreate.
6. If no call has bean placed but coins have been deposited, refund the coins upon hanging up.  Or if coins have been deposited and a "free" number has been dialed return coins.

Notes:
Since the phone I am using is touch tone the controller dose not have to work with pulse dialing but that would be a plus
I like DSK's idea for polarity reversal for answer detection but am open to other suggestions
Would a dtmf tone detector work to differentiate "free" and "non free" calls?

[ESalter]

Making a device to do what you want would be near impossible for 99% of people.  My dad and I are very technically oriented people and even our coin line simulator doesn't do half the stuff you listed.  First, the switches on the back(or front) of the chassis board that set initial rate...  they don't make any difference at all.  All it does is the chassis counts the money and closes an initial rate contact when that amount has been reached.  All the while the totalizer pulses out the value of the coins so the coin line counts them as well.  I think "Initial Rate" in redundant for that purpose.  Anyway, if you want it to do all that, I'd recommend a Protel board.  You can find them for around $50 and $25 for it to be programmed.  It would be capable of all you want.

---Eric