Nah, 370/158, 4341s. 1980s.

-----Original Message-----
From: IBM Mainframe Discussion List <[email protected]> On Behalf Of 
Doug Fuerst
Sent: Friday, November 7, 2025 4:38 PM
To: [email protected]
Subject: Re: Ancient history: 3420s

If those tape drives were on a 7090, they were probably 729's. They went on 
7080's, 7090's, and 7094's mostly. Some 1610's IIRC.
Long time ago. First machine I fixed as an FE. Equitable Life in NYC.
1973 I think.

Doug Fuerst


------ Original Message ------
>From "Phil Smith III" <[email protected]>
To [email protected]
Date 11/7/2025 16:31:55 PM
Subject Re: Ancient history: 3420s

>Ah, sorry, I meant to say: it was a physical label on the tape. Kinda an 
>important detail I omitted! So it wasn't "security" per se, more like the Luhn 
>on a credit card, to avoid entry error (in this case, "grab error").
>
>-----Original Message-----
>From: IBM Mainframe Discussion List <[email protected]> On 
>Behalf Of Paul Gilmartin
>Sent: Friday, November 7, 2025 4:28 PM
>To: [email protected]
>Subject: Re: Ancient history: 3420s
>
>On Fri, 7 Nov 2025 14:42:59 -0500, Phil Smith III  wrote:
>
>>Lots of unlabeled tapes, especially on VM.
>>
>>This was a backup for that.
>>
>How was that "4-character hash " communicated to the operator?
>
>
>>On 11/7/2025 9:52 AM, Phil Smith III wrote:
>>>
>>>  The 3420 reminds me: back at UofW, they had a system that would create a 
>>> 4-character hash (I assume) from the tape number. So when you asked for 
>>> tape 1234, the operator would pull it and when they responded to the mount 
>>> request, they had to enter that 4-character value. If they'd accidentally 
>>> pulled 1235 instead, there would be a mismatch and it would tell them to 
>>> try again.
>
>--
>gil
>
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