Typo. Some RCA drives had two vertical columns on either side of the R/W heads, using gravity rather than pressure differential. As i recall the drives for metal tape used gravity bins and the drives for plastic tape used vacuum columns. I also recall the 3301 being the last machine to support metal tape.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 עַם יִשְׂרָאֵל חַי נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר ________________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of Pommier, Rex <[email protected]> Sent: Wednesday, June 25, 2025 4:19 PM To: [email protected] <[email protected]> Subject: Re: 3420 environmentals? External Message: Use Caution IBM 3422 was a vertical stack - made by Siemens I believe. I never used one, but I have used an NCR vertical stack tape drive a long time ago that didn't have vacuum columns (that I remember). What is " bgrvity"? Did you mean gravity? If you are talking about single reel tape drives that had a bin under them that the tape just fell into after going thru the head, I can answer "yes". NCR century 200 machine from the mid-60s. I was introduced to it around 1981. We called the bin the "bit bucket". Rex -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Seymour J Metz Sent: Wednesday, June 25, 2025 2:49 PM To: [email protected] Subject: [EXTERNAL] Re: 3420 environmentals? It doesn't look like any tape drive I can remember, what with the vertical stacking and no vacuum columns. Has anybody here used a tape drive with bgrvity bins?? -- Shmuel (Seymour J.) Metz https://urldefense.com/v3/__http://mason.gmu.edu/*smetz3__;fg!!KjMRP1Ixj6eLE0Fj!sTX1peQQ8iV4cgLVRUtVMEfhBIUXkaxQzp-EH6OtthXgL3dcEhaArQFEXWasj0ChH_OmMdlEyhgg_kakQg$ עַם יִשְׂרָאֵל חַי נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר ________________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of Phil Smith III <[email protected]> Sent: Wednesday, June 25, 2025 1:01 PM To: [email protected] <[email protected]> Subject: Re: 3420 environmentals? External Message: Use Caution Thanks! (To you and others) Back in the 80s, we had 3420s in a room that had some sort of cooling but was not a data center per se. The cables ran through a 6" hole in the floor down two stories to the real data center; the controller was downstairs as well. And I'm also 100% sure those holes in the floor were in violation of code :) I've occasionally driven by the building (35+ years later) but never had time to stop and see if the holes were still there. This was prompted by someone wondering about what looks like maybe a 3420 in this cartoon: https://urldefense.com/v3/__https://secure-web.cisco.com/1AdVw0CgjF_831dCj8dHlOitTPupTJb0yxqHQ0s6aWIt8TllkulVZYaQ1NF52O2l-XVPp_Kvxioe_QWLGY4tb2PpFts4y3gyKSG8HfLCI9rmbNo86-2TzBizKfbMeqwlYQAsKp5a5qgqZBAIdmQYKhE1qPnBkUY2hrRhQG6Wx4bTfwgpa4SghGzV8eT7zzPah2aupqQZXfD9w0GDnXrXvY7yzzSNvboydmNw2yB4bp0GHkIX6VuOI69xTKxoVhgKUbS9VknkydnrFKU5uzhNkyviGzrD__CDrdOl0Ug6heUmlEEPYGoIRXZmE9Dcsm2r6qDNrOSFn8hGYN9TkvxjmDlDDOINkrCx8SoCNKSbysvDYm75zvhaU1UTopFGlaEy4Wsvb5lkjqsGI3ZZ-OJxdTujZ5CepQBPuEPEgu2ynSIw/https*3A*2F*2Fcidu.info*2Fwp-content*2Fuploads*2F2025*2F06*2Fj.jpeg*3Fw*3D1024__;JSUlJSUlJSUlJQ!!KjMRP1Ixj6eLE0Fj!sTX1peQQ8iV4cgLVRUtVMEfhBIUXkaxQzp-EH6OtthXgL3dcEhaArQFEXWasj0ChH_OmMdlEyhiwMasmyA$ noting that they weren't sure it could be used in a normal office. Since this is a military setting, I'm supposing that strong floor, extra cooling, etc. shouldn't be a blocker... -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Harry Wahl Sent: Wednesday, June 25, 2025 10:06 AM To: [email protected] Subject: Re: 3420 environmentals? Phil, Here is a link to the applicable physical planning guide with requirements: https://urldefense.com/v3/__http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/370/fe/GC22-7064-13_Input_Output_Equipment_Installation_Physical_Planning_Mar93.pdf__;!!KjMRP1Ixj6eLE0Fj!sTX1peQQ8iV4cgLVRUtVMEfhBIUXkaxQzp-EH6OtthXgL3dcEhaArQFEXWasj0ChH_OmMdlEyhjIPmvHqQ$ Look on page 112. When I worked for IBM in the 1970s I saw a few running in offices sometimes with a 3803 sometimes without. Usually with the channel or control unit cables snaked under or through a wall. The intent was to keep people out of the mainframe room. Also, they required 3-phase electricity and the floor had to checked to make sure it could support the weight. Standard building codes specify how much weight an office floor must support and it was much less than the 3803/3420's weight so a licensed engineer had to certify that that particular floor could support its weight. Dr. Harry J. Wahl ________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of Phil Smith III <[email protected]> Sent: Wednesday, June 25, 2025 9:19 AM To: [email protected] <[email protected]> Subject: 3420 environmentals? Anyone remember whether 3420s had to be in a chilled room or not? Could you have had one in a regular office? I forget how much heat they put out. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
