Coin Handling

Runway chassis Fastenings

With coin handling door leaf open

The Validator

Coin Handler Assembly 12 A

617/1/04022/000

Software thoughts from CB

.......how I think the coin mech works, and I

explained what I knew. The coins in the mechanism 12A which is in most of my CT24/25 & 34s, works with firmware V15, what we think is the last version. The mech has two escrow paths, an upper and lower. He wanted to know what decides where each coin will go. I told him a data table was responsible. It has these values: 009H, 009H, 060H, 010H, 060H, 000H. If the upper nibble is present the coin is sent to the lower escrow, if not its sent to the upper. Gate 2 does the selecting.

I know it has to have six entries, one for each coin the validator can

recognise. The early firmware, including issue 4, can recognise 2p, 5p,

10p, 20p, 50p and £1, i.e. six different coins, probably with a minimum

fee of 8p, like the CT22s. By the time V15, which I am analysing, came

out BT had given up accepting the 2p and 5p, so V15 had to deal with

only four coins: 10p, 20p, 50p and £1. but by the looks of that table it accepts *5* coins, so what was the extra one? Maybe £2, but they arrived a few years later.

One problem has been nagging away at me: how does the firmware know what the value of each coin is? Initially I expected the values to be in the

table, but they are not. Also, were the values in binary pence, i.e. 0A, 14, 32, & 64 in hex, or BCD, as they are displayed, i.e. 10h, 20h, 50h

and... err, what, exactly?

Then tonight I found it. The table was bigger than I thought, and the following values were *before* the table entries I already knew about.

Here they are, and no, this is NOT a typo: 00AH, 014H, 032H, 032H, 064H, 000H.

These six bytes are the values of the six possible coins in straight binary, presented in hex. I.e.

Coin A, 00Ah = 10,

Coin B, 014h = 20,

Coin C, 032h = 50 and then, eh? what's this?

Coin D, 032h = 50p again,

Coin E064h = 100p/£1 and finishes with

000h, = 0, i.e. no coin F.

Why two 50ps? Because we know V15 is 1995 at the earliest and probably later. In 1995 they stopped minting the old large 50p and restarted in 1997 with the current smaller 50p. So, V15 had to be able to accept both the old large 50p and the then new smaller 50p as both were still in circulation.

Coin Gates and Coin Sensors

Coin Deflector Assembly

Coin Entry assembly adjustments

Stage 1

With the coin deflector plate removed and the fixing screws of the validator portector mechanism loose, insert the setting gauge into the coin slot untill abut 3mm remains protruding
Veiwed from the rear of te fornt panel, position the settign gauge and protection mechanism as shown. press the protrusing edge of the gauge firmly downwards
holding the protection mechanism in the set postion tighten the fixing screws
withdraw the settign gauge

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