Hot answers tagged

62

The message appears in sudo’s revision control (in its current guise) in June 1993, in the University of Colorado version of sudo, in a slightly shorter form: We trust you have received the usual lecture from the local Systems Administrator. It usually boils down to these two things: #1) Respect the privacy of others. #2) Think before you ...


24

In later versions of Unix, Ken Thompson would most certainly have been able to use upper-case characters but it's unclear whether he would have wanted to. It's not that Unix itself prevented it, but rather that there were still plenty of terminals at that time that supported only the 64-character ASCII character set, which were upper-case only. The "7th ...


14

LOGO was intimately tied up with research into educational methods, and in teaching children how to use computers. The project proposal by Seymour Papert mentions "research on children's thinking and elementary education". Further LOGO memos are found here. The question remains is, is this what the language was "originally" for, or was the language co-...


13

Yes, you could use uppercase and special characters in passwords in early Unix. No, there was no Unix-related reason Ken Thompson wouldn’t have been able to use uppercase or special characters. Many of the passwords found in 2014 used special characters; none used uppercase, which doesn’t say anything about the original password requirements, only about the ...


11

The question is tricky in a fundamental way. [...] very high uptime [...] longest continuous runtime One part lies in the definition of these, partly contradicting, terms as well in what the computer is. Uptime is a term used for high level operating systems - such as a Unix system - but the Voyager systems are embedded computers running their ...


10

For the same reason you don't build a bridge by grabbing some metal and stone, dragging it to the shore of a river, and start stacking it and bolting it together. Trying just to build and run the Analytical Engine from incomplete plans is about as likely to work or be useful as typing in an incomplete computer program and "just running it." But worse, ...


7

According to Wikipedia: Logo, second paragraph fragment The language was conceived to teach concepts of programming related to Lisp and only later to enable what Papert called "body-syntonic reasoning", where students could understand, predict, and reason about the turtle's motion by imagining what they would do if they were the turtle.


5

Seymour Papert was a developmental psychologist, and in the early days of computers had lots of interesting ideas about how children might be taught using them. His work's online if you're interested. The "real" turtle wasn't like the autonomous robot "tortoise", it was simply a plotter on wheels. A domed robot with 2 large wheels, one per side, that could ...


2

If you examine the cartridges produced during the active life of 8-bit computers, then first of all you need to look at the Japanese and MSX. One-, two-, three-megabit cartridges with mappers were produced in rather large editions - in general, the picture was similar to the one that Sega had for the Master System. Megabit ROM Cartridges


2

As Raffzahn points out, because memory can be bank-switched in the address space available to cartridges, the maximum size is limited only by the intersection between the technology available and how expensive and physically large you're willing to make the cartridge, and how you're willing to power it. Nonetheless, you're probably thinking of cartridges of ...


2

All the various LISP 1.5 systems (on the IBM 7090 and otherwise) appears always to have used only PLUS, DIFFERENCE, MINUS (unary), etc. (§4.2 p.25) Its small derivative PDP-1 LISP (1964) also did as well (§2 p.3 Table 1, though I don't know what happened to DIFFERENCE.) LISP 2, discussed extensively in the early '60s but never implemented, did use symbols ...


1

The largest ROM space the Atari 2600 could address was 4K. But a number of bank switching schemes (and some fiendishly clever ways to do it cheaply!), allowed carts up to 32K. Although really there's no limit, you can always amend the bankswitching to allow more. This applies to all consoles, and computers. With bankswitching, possible with all ROM-based ...


1

Background: The Original PET Keyboard and PETSCII Most of these keys have their roots in the original Commodore PET 2001 keyboard: The scanning and conversion was complex and seems to have varied somewhat by ROM version, but eventually a PETSCII code would be produced from a keypress. For the original keyboard, typing a key with a printable character would ...


1

Memory may not have been quite so much of an issue as people were making it out to be. Keep in mind that the base version of the Altair 8800 (kit price $439) shipped with a "1024 word" (by which they mean byte) memory board populated with only 256 bytes of RAM. If you were willing to work with less, and in particular design your computer to use RAM more ...


Only top voted, non community-wiki answers of a minimum length are eligible