# 1950s computers: question #1 **URL:** \ **Category:** Factual Questions\ **Created:** [August 8, 2025, 7:47pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875 "2025-08-08T19:47:45Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![K364](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k364/32/5_2.png) [@K364](https://boards.straightdope.com/u/K364)\ **Post date:** [August 9, 2025, 7:29pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/21 "2025-08-09T19:29:03Z")
I just bought two 128 GB thumb drives for $12 each. And tiny things they are, about 1 1/2 long and 1/4 inch thick. Imagine someone from the 1950’s trying to wrap their head around that! ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [August 9, 2025, 7:53pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/22 "2025-08-09T19:53:05Z")
> [@K364](#): > > I just bought two 128 GB thumb drives for $12 each. And tiny things they are, about 1 1/2 long and 1/4 inch thick. That big, eh? My tablet has a 256 GB microSD card about the size of my pinky toenail that currently contains several dozen HD movies and all the episodes of _Seinfeld_ and _Fawlty Towers_ with room to spare! 😉 Yes, technology is, generally, good stuff! ---
**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:** [August 9, 2025, 7:56pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/23 "2025-08-09T19:56:17Z")
As you point out, the “active ingredient” inside a thumbdrive is the size of a pinky toenail. But since they’re called thumbdrives, not pinkkytoenaildrives, the exterior packaging has to be larger. A lot larger. Sorta thumb-sized actually. ---
**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:** [August 9, 2025, 7:57pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/24 "2025-08-09T19:57:42Z")
> [@Chronos](#): > > Addendum to that: It looks like the TI-84, which certainly qualifies as “nowadays” given that nearly every high schooler has one, also [uses BCD internally for floats](https://www.merthsoft.com/linkguide/ti83+/vars.html#real). Not implemented in hardware, though. Also, it uses a Zilog Z80… a chip that’s almost half a century old. I still want to know who TI paid off to get their calculators embedded in the schools for so many decades. Or was it that the lack of meaningful development for so long proved to be an advantage in that environment? ---
**Author:** ![K364](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k364/32/5_2.png) [@K364](https://boards.straightdope.com/u/K364)\ **Post date:** [August 9, 2025, 8:12pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/25 "2025-08-09T20:12:35Z")
I worked in a Computer Center in the 1990’s. It was room the size of a basketball court completely filled with equipment. Most of the equipment was disk storage units the size of a large refrigerator. They probably held 16MB. And each one had a “Controller” also the size of a fridge. IBM rarely sold integrated equipment - you had to buy the associated Controller separately. What a racket! ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [August 9, 2025, 8:23pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/26 "2025-08-09T20:23:56Z")
> [@K364](#): > > IBM rarely sold integrated equipment - you had to buy the associated Controller separately. What a racket! No, the need for separate controllers was a technical necessity in those days, but this is not in defense of IBM. The real racket was that in those days, IBM rarely actually sold anything – their business model was leasing, and what they charged for the lease had almost nothing to do with the actual cost of the equipment, it was all about the value to the business. If IBM had something that could quadruple your profits, and it only demanded 20% of that, then – win-win! Never mind that the product only cost 0.01% of your profits. If you wanted to know what some piece of IBM equipment cost in those days, it was quoted as $x per month. That was the cost. Per month, The Bell monopoly got in on that racket years before, but IBM cranked it up to a major scale. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [August 9, 2025, 8:33pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/27 "2025-08-09T20:33:22Z")
That’s nice, but did not help so much in the **1950s** , when the big fucking refrigerator might provide 4k of RAM and leased for $6,000 per month. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 9, 2025, 9:34pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/28 "2025-08-09T21:34:29Z")
> [@Francis\_Vaughan](#): > > But if you had a bit of COBOL that read > > `Date PIC 999999` > > You had some very specific (and unfortunate) expectations about how things wee going to work. Translation, please, for those of us fortunate enough to not know COBOL? > [@Dr.Strangelove](#): > > I still want to know who TI paid off to get their calculators embedded in the schools for so many decades. You and me both. Even in 1993, the TI-83 was only, like, the third-best graphing calculator on the market. ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [August 9, 2025, 10:24pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/29 "2025-08-09T22:24:15Z")
“Date” is six bytes numeric, positive only. (Technically ‘unsigned,’ but unsigned is de facto positive.) ---
**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:** [August 9, 2025, 10:46pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/30 "2025-08-09T22:46:00Z")
Not necessarily 6 bytes. 6 decimal digits. ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [August 9, 2025, 11:02pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/31 "2025-08-09T23:02:49Z")
As it was written, yes, necessarily, having no other qualification such as comp or comp-3. Six bytes, six numerals, and no decimal points. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [August 10, 2025, 3:25am UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/32 "2025-08-10T03:25:17Z")
> [@DPRK](#): > > That’s nice, but did not help so much in the **1950s** , when the big fucking refrigerator might provide 4k of RAM and leased for $6,000 per month. The DEC PDP-10 (aka DECsystem 10) seems old today but was contemporaneous with my youth – the original KA10 was one of two mainframes at the computing center of the university I attended in my undergrad years. (I had the pleasure of hacking it and getting operator-level control, and among other things dumping out all the (unencrypted) passwords to everyone’s account!) 🙂 But I digress. In this picture, one of those oversized-refrigerator-size cabinets with a big row of blinkenlights at the top contained 32K 36-bit words of core memory. So a typical machine with, say, 256K words of memory would have eight of those gigantic cabinets just for the core memory alone. I’m not certain but I think that the cabinet to the immediate left of the console was an integral part of the processor and held part of the backplane, and the one to the left of that held the mandatory minimum 32K of core memory. I’m also going to take a wild guess and suggest that the cabinet at the far end of the row of cabinets on the left, the one that looks different from the others, was probably the controller for the disk drives. The first generation PDP-10 would have used RP02s, drives the size of washing machines which I believe had the awesome capacity of 20 MB each! [![](https://upload.wikimedia.org/wikipedia/commons/d/db/DEC_PDP-10_%28DECsystem_10%29_mainframe_computer_system_at_Living_Computer_Museum_%28strongly_edited_image%29.jpg) ](https://upload.wikimedia.org/wikipedia/commons/d/db/DEC_PDP-10_%28DECsystem_10%29_mainframe_computer_system_at_Living_Computer_Museum_%28strongly_edited_image%29.jpg) ---
**Author:** ![phs3](https://avatars.discourse-cdn.com/v4/letter/p/8491ac/32.png) [@phs3](https://boards.straightdope.com/u/phs3)\ **Post date:** [August 10, 2025, 5:18am UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/33 "2025-08-10T05:18:27Z")
> [@K364](#): > > Most of the equipment was disk storage units the size of a large refrigerator. They probably held 16MB. Ehh…. wasn’t quite that primitive. 3390-3 (introduced 1991) were about 2.7GB per drive. Huge! (they seemed) ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [August 10, 2025, 8:58am UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/34 "2025-08-10T08:58:13Z")
> [@phs3](#): > > 3390-3 (introduced 1991) were about 2.7GB per drive. You young whippersnappers don’t remember the good ol’ days. The DEC RP02 was, as I said, 20 MB, the RP03 was about twice the capacity, and the Big Boss of the day was the fabulous DEC RP04 (actually a rebrand of a Sperry clone of an IBM 3330) with a staggering capacity of 88 MB! This was in the 70s. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [August 10, 2025, 9:00am UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/35 "2025-08-10T09:00:25Z")
By “4kword refrigerator” I was thinking of the IBM 737… outright buying 32K of core in the 1950s would have cost 7 figures, I am guessing. With this and the other question, I have to point out that an IBM 701 simulator, software, assembler, compilers, manuals, sample code, etc. are all available online, if someone really wanted to see how efficiently they could code for it. Eh, ask an old-timer (if you can find any left) sometime how much they paid for 32 _bits_ in the 1940s… ETA I see the discussion is about disk drives? The IBM 350 came out in 1957 and had 5 million characters. Not sure how we have arrived all the way to the 1970s 🙂 ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [August 10, 2025, 9:15am UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/36 "2025-08-10T09:15:58Z")
> [@DPRK](#): > > With this and the other question, I have to point out that an IBM 701 simulator, software, assembler, compilers, manuals, sample code, etc. are all available online, if someone really wanted to see how efficiently they could code for it. That’s a bit too far back in history for me to be interested, but all the things you describe are available for more recent IBM and (especially) DEC computers. I have a simulator for the venerable DEC PDP-10, and a bunch of classic programs for it like Adventure and MacHack, the famous chess program that beat the philosopher and AI skeptic Hubert Dreyfus. I really wanted a chance to play chess with MacHack again, and I must say I’m quite proud of my sleuthing efforts. I eventually tracked down an online image of a DECUS 9-track magnetic tape (DECUS = DEC Users Society, an organization of DEC customers, which held regular conferences and shared software). Since the PDP-10 simulator could simulate PDP-10 devices including magnetic tape drives, I added a virtual tape drive, and “mounted” the tape image on it. As a user, I had to send a tape mount request to the operator, and then the operator (me again, in another window) acknowledged the request and gave me control of the mounted tape. And by golly, I was able to copy over MacHack from a 50-something-year-old tape image and play chess with it, just like it was the 70s again! ---
**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:** [August 10, 2025, 1:33pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/37 "2025-08-10T13:33:14Z")
Did you win? ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [August 10, 2025, 2:58pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/38 "2025-08-10T14:58:39Z")
> [@wolfpup](#): > > I’m also going to take a wild guess and suggest that the cabinet at the far end of the row of cabinets on the left, the one that looks different from the others, was probably the controller for the disk drives. I think that’s not the case. I did some Internet digging and found the Christie’s auction for the late Paul Allen’s PDP-10, of the same vintage as the one in the Wikipedia image. > **[A DEC PDP-10 KI10 MAINFRAME COMPUTER](https://onlineonly.christies.com/s/firsts-history-computing-paul-g-allen-collection/dec-pdp-10-ki10-mainframe-computer-125/230064)** > > Serial no. 676Comprising three KI10 bays, one DEC tape control, one AMPEX ARM 10LS semiconductor storage cabinet, one DAS33 AB buffered data channel, two RH10A data controls, two ANF10 sync/async, one DL 10 AB PDP-11 Data Link interface, one DC10A... The following image shows the equivalent cabinets, including the “odd one out”. [![](https://www.christies.com/img/LotImages/2024/NYR/2024_NYR_23618_0125_018(a_dec_pdp-10_ki-10_mainframe_computer_digital_equipment_corporation_19083942).jpg) ](https://www.christies.com/img/LotImages/2024/NYR/2024_NYR_23618_0125_018(a_dec_pdp-10_ki-10_mainframe_computer_digital_equipment_corporation_19083942).jpg) It’s zoomable, and zooming in on the nameplate shows it’s an AMPEX ARM 10LS, which is a 256-kiloword semiconductor\* memory cabinet. > **[Ampex ARM10 - Computer History Wiki](https://gunkies.org/wiki/Ampex_ARM10)** \*instead of core, which the AMPEX ARM10 was. ---
**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:** [August 10, 2025, 3:08pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/39 "2025-08-10T15:08:47Z")
Never mind. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [August 10, 2025, 3:45pm UTC](https://boards.straightdope.com/t/1950s-computers-question-1/1021875/40 "2025-08-10T15:45:02Z")
> [@gnoitall](#): > > I think that’s not the case. I did some Internet digging and found the Christie’s auction for the late Paul Allen’s PDP-10, of the same vintage as the one in the Wikipedia image. Youi’re probably right. The image I posted, from the looks of the console, was a KI-10. The one at my university was the original KA-10, and at that time the memory cabinets were indeed 32K words per cabinet. > [@LSLGuy](#): > > Did you win? No! 😁 I’ve played many chess programs, good and bad, and what I always liked about MacHack was that it wasn’t just a good chess program, it was a mercilessly aggressive one. Make one bad move, and it’ll be all over you! Ironically, it wasnt as good as Shredder, a chess program I bought for my tablet. Shredder has settable levels where at lower settings it makes stupid mistakes simulating a novice player, but at higher settings, man, this thing is good. I once posted a game between MacHack and Shredder (at one of its higher settings) and Shredder was victorious! It was the only time I’ve ever seen MacHack lose a game. [Previous page](https://boards.straightdope.com/t/1950s-computers-question-1/1021875.md?page=1) [Next page](https://boards.straightdope.com/t/1950s-computers-question-1/1021875.md?page=3)