# Energy needs of UNIVAC type computers **URL:** \ **Category:** Factual Questions\ **Created:** [November 21, 2023, 11:44pm UTC](https://boards.straightdope.com/t/energy-needs-of-univac-type-computers/993501 "2023-11-21T23:44:59Z")\ **Posts on this page:** 6\ **Page:** 7
**Author:** ![snfaulkner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snfaulkner/32/433_2.png) [@snfaulkner](https://boards.straightdope.com/u/snfaulkner)\ **Post date:** [December 30, 2023, 11:02am UTC](https://boards.straightdope.com/t/energy-needs-of-univac-type-computers/993501/121 "2023-12-30T11:02:29Z")
Ah yes. The IBM model M. Hefty enough to crush a skull, robust enough to live through a dish washer to clean off the blood. I’ve got one in storage that I’m sure still works. Built in 1982. ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [December 30, 2023, 12:13pm UTC](https://boards.straightdope.com/t/energy-needs-of-univac-type-computers/993501/122 "2023-12-30T12:13:25Z")
A better weapon would be an actual 3270 terminal keyboard from the 1970’s. Those were a 122-key monster about 18" wide, in a solid metal case. They weighed close to 20 pounds (10 kg), I think. More than once I’ve dropped one from waist-high onto a solid floor, and they were still working! Didn’t even show any noticeable damage to the case. That would do real damage. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 30, 2023, 2:25pm UTC](https://boards.straightdope.com/t/energy-needs-of-univac-type-computers/993501/123 "2023-12-30T14:25:55Z")
[Tiresome Pedant mode] > [@Tim\_T-Bonham.net](#): > > And if you still have an original one with the round PS/2 cord connector, The small (~1/4") round mini-DIN connector that fit PS/2s was the second generation PC keyboard connector. The first generation keyboards that fit original PCs, PC/XTs, PC/ATs, and all their clones had a ~1/2" diameter DIN-style plug. See here for more: **[IBM PC keyboard | Connection - Wikipedia](https://en.wikipedia.org/wiki/IBM_PC_keyboard#Connection)**. [/Tiresome Pedant mode] But other than that, thanks for sharing some excellent ancient history there. Been many many years since I typed on an M-style keyboard. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [December 31, 2023, 8:40pm UTC](https://boards.straightdope.com/t/energy-needs-of-univac-type-computers/993501/124 "2023-12-31T20:40:21Z")
> [@Dr.Strangelove](#): > > Required reading for anyone calling themselves a hacker: [The Story of Mel](http://www.catb.org/jargon/html/story-of-mel.html) Yes, that sounds a lot like the computer my dad described. Another fun note, Mel was mentioned using chunks of code as data. A friend of mine who was deep into the TRS-80 disassembled some of the ROM. He found at least one instance where the routines jumped into the middle of another routine, mid-instruction. (I.e the second byte of a two-byte instruction). Apparently, some clever programmers, rather than writing a very short subroutine, searched the assembled machine code for the proper sequence of bytes in existing code, found them, and saved a few bytes of ROM memory by using that. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [December 31, 2023, 9:00pm UTC](https://boards.straightdope.com/t/energy-needs-of-univac-type-computers/993501/125 "2023-12-31T21:00:47Z")
> [@md-2000](#): > > Apparently, some clever programmers, rather than writing a very short subroutine, searched the assembled machine code for the proper sequence of bytes in existing code, found them, and saved a few bytes of ROM memory by using that. Hmm, neat! That same technique is still in widespread use among malicious hackers, now called [return-oriented programming](https://en.wikipedia.org/wiki/Return-oriented_programming). Essentially, in some situations where you’re trying to exploit a system, you can’t execute arbitrary code, but you _can_ jump to a sequence of arbitrary addresses. So you look around what’s already in memory for sequences of instructions at the end of existing functions, looking for ones that you can reuse and chain together for your own ends. Modern software like a web browser is so large that it’s very likely you’ll find enough pieces to achieve what you’re going for. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [December 31, 2023, 9:02pm UTC](https://boards.straightdope.com/t/energy-needs-of-univac-type-computers/993501/126 "2023-12-31T21:02:09Z")
> [@Sam\_Stone](#): > > I think it was the IBM System/360 (don’t quote me - it might have been a different computer of the time) that came in a slower model and a faster one. If you wanted to upgrade the slower one to the faster one, a technician came out and _removed_ a board. The slow machine had a boars in it that had the sole function of injecting wait states to slow everything down. You may be thinking of Amdhal, the biggest System 360/370 clone. Our IT manager went on a rant one time about how they only made one version, so they stuck a board into the CPU cabinet to consume clock cycles if you didn’t want to pay for a faster computer. Made sense when rental rates were in the hundreds of thousands (millions?) per year. Apparently IBM was shocked that we went with Amdahl, they were more reasonable when the next upgrade time came around. > [@Voyager](#): > > I’m not sure most, but it was definitely a thing. Like your telephone equipment. In the Bell System days we built things sturdy so that it would never have to be replaced, and keep earning rental revenue. After the split I went to a talk about how to build quality out of equipment because when we sold the stuff it no longer made sense to spend extra so it never broke. Yes, our system was like a tank - actually, a huge colection of racks… Toward the end, we were buying parts on eBay, When they finally went to VoIP they sold the contents of the rack to a company down the road who still used that model. If it works, don’t mess with it. (VoIP was fun… Caller ID had a limited number of characters. Internally you wanted to see the name of who was calling, but there was no way to change that to company name on outbound calls… much confusion for a long time.) > [@Darren\_Garrison](#): > > This makes me remember something from my childhood. People were just recently being allowed to buy their own phones. My grandmother got one at a green stamp store, and you had to call the phone company and “register” that you were using a 3rd party phone (this was outside of stopping renting the company’s phone). Did that actually involve them _doing_ anything to the signal on their end, or was it pure bs? > [@JohnGalt](#): > > There was a thing called REN: Ring Equivalent Number, which had to do with the power required to “ring” the phone. Yes. When we switched to VoIP the phones also used 24V instead of 48V for ringers. ome of the really old phones with those mechanical bells no longer worked. (The bell would ring weakly if you laid it sideways so th hammer had gravity assist). There was a whole discussion somewhere about how the phone company in the good old days could measure ring power and determine if there was an unregistered extension. Technically, in the Goode Olde Days, they had to wire everything and were responsible to fix anything if the phones stopped working, hence the anal control. Eventually, with deregulation, they basically provided service to the house and wiring inside was your problem, you fix it. [Previous page](https://boards.straightdope.com/t/energy-needs-of-univac-type-computers/993501.md?page=6)