I recall hearing people theorize about this, usuallu when trying to explain that “they really did try and call last night”- does this have any merit?
Busy signal? 
Sorry, I meant to where the two calls would go to the switchboard(?) at the exact same time, and a result, neither calls goes through (phone doesn’t ring in),
and neither caller gets a busy signal?
On second thought, maybe I shouldn’t post under the influence, becaue I don’t even know if this makes any sense, or if it is one the great revelations you have under the influence and then when you think about it the next day it seems not so insightful. Off to bed for me… :wally
Nope. As best as I recall, the circuits were pretty much a “first come, first served” deal. One of those calls would be connected first, and the next, even if off by a fraction of a second, would get a busy signal.
Basically, I’m saying that in that era, there was no possibility of both calls arriving simultaneously. One would get there first, and the next would get a busy signal.
‘Party Lines’
- it was amusing, your 'phone would rumble, and you listened to your neighbours
It certainly happened in the UK
The worst case was more like this.
Your’e talking on the phone. Another person starts to dial you. It took a while to call, dialing was way slower than touch tone. The other party hangs up and you are about to, when someone else is on the line all of a sudden. It happened rarely.
Yep, and while rare, it wasn’t extremely rare, I’d guess most people had the experience once or twice.
If two calls did arrived at exactly the same instant, very unlikely, they’d probably both get a busy.
How would you know they were simultaneous? Maybe for few minutes, your line was unavaiable to anyone.
This reminds me of a prank we used to pull, when I was a teenager in the 50’s. You could call someone, usually from a pay phone, lay the phone down and it would tie up their line until the calling phone was disconnected, or the operator interceeded.
Can’t happen. The precise same time is a time span of zero width and the probability that two calls would occur within it is pretty small, to say the least.
Nope, once the X-Y switches started moving that’s it.
I know of cases where you would pick up the phone to make a call and someone was already there: they call had gone through, but you picked up the phone before the ringing mechanism started.
I had the pick it up and someone’s there happen too. They both are for the same reason. You happened to have the phone in your hand when someone called , so the ring never happened.
Ignore my previous post. :Talking Through Hat:
When you say 70s are you asking about silicon or presilicon?
In 1970 I still had an eight party line and X-Y switches were still common.
I know this is an old post but I remember many times picking up the phone to dial and thinking it was dead, but just to be sure you say hello and your friend or family member answering because they just happened to be calling you and you picked up before the first ring.
This was a famous scam trick - someone would call claiming to be from, say, the bank or the police; “you can verify this by calling us back” they would say, but not hang up. They would have the gizmos or recording to fake a dial tone and ringing. The person would dial the number, think they were talking to someone who could verify the call, but in fact the original caller had never hung up.
I know ITGOD (in the good old days) you could leave a phone ringing foever and ever; People really trying to get ahold of you would ring for 10 or 20 rings before giving up. (7 was my norm…) After all, there was only the 1 phone in the house, so maybe they had to run up from the basemnt or in from outside.
While the phone was ringing, anyone else calling would get a busy signal. This caused no end of annoyance.
“I called and you didn’t answer.”
“I was out.”
“No, first call was busy, so I called back a minute later and it rang and rang…”
“But I was out…”
Also, yes, I had on occasion picked up just before it rang. Pickup, and as you are dialling, someone says “Hello? Hello?”
That depended on the local phone company setup. In many of them, if the called party hung up, the circuit was disconnected after a certain amount of time (1-3 minutes), even if the calling party phone was still off-hook.
Of course, this was 1-3 minutes of on-hook time for the called party’s phone. If yo happened to pick up the phone during that time to make another call, that restarted the timer. So if you were impatient and kept trying to make a call, you were actually keeping the circuit open.
About 50 years ago, I picked up a non-ringing phone to hear someone already on the line and it was the very person I was about to call. (Since a contact was needed – carpool to a cub scouts meeting or something – it was probably only a 500-to-1 longshot or so, but still seemed odd enough to linger in memory unmentioned until now … 50 years later! :smack: )
BTW, does anyone remember the peculiar rings one could get (at least in parts of California) in those days?
Dial 11966 (or something) and hang-up to hear Brr-Brr-Beep Brr-Brr-Beep etc.
Dial 11967 to hear Brr-Beep-Brr-Beep, etc.
(I think they were used by telephone repair.)
Small, but perhaps not utterly zero. For example, imagine a vertical rod so perfectly positioned it can’t decide which way to fall; it could in principle remain vertical for quite a while.
I used to work in circuit design and simultaneous set/reset was sometimes (though rarely) a concern. (Solution was sometimes just to make the probability of “metastability” very very very small.)
I don’t know how helpful this will be since it’s anecdotal and I was never successful at it, but there was some sort of anomaly in some circuits that would create a sort of primitive party line chat room of sorts.
In high school (in the 70’s) we called it the “buzz line”. How it was supposed to work was you would call a number that you knew to be busy or overloaded, typically a radio station’s contest line and instead of getting the typical busy signal, you would be dumped into some sort of phone company void with other callers and could chat among them.
As I said, I was never successful doing this, but I do remember myself and my friends trying, and I do recall at times dialing the “buzz line” and getting into the void, but never actually talking to someone else in that void.