thequux

11 ms·

61.
by thequux 3y ago
Indeed, this is wrong. However, 3^3 is 27, which is less than 32, so you can easily encode each row in 5 bits. The encoding into those 5 bits is precisely the base-3 encoding from the article, so I'll leave it as an exercise for the re
62.
by thequux 3y ago
Z doesn't really have files or databases, but rather an emulation of variable-length records contained within a relatively fixed allocation on disk. Mainframe DASDs also have a much richer interface than just read/write a given
63.
by thequux 3y ago
> Perfect! I've worked with a lot of C kernel security devs and I don't think I've ever seen one of them write something not Cish, like python/ruby/go/etc. There are a couple of us true full-stack developers
64.
by thequux 3y ago
It is often useful to also watch for calls to the stat family of syscalls; some applications stat files that they wish to open rather than depending on the return code from open, so just looking for open will miss files that don't exis
65.
by thequux 3y ago
I'm a big fan of `sed -nel` for an unambiguous listing of the contents of a file. The only case that sed doesn't show is a missing trailing linefeed.
66.
by thequux 3y ago
Largely no, actually; modern z/Architecture is a strict superset of the System/360 ISA from the 70's. Every instruction that accesses memory has the original 24-bit address version, a 32-bit version, and a 64-bit version that
67.
by thequux 3y ago
Scheme was the third in a series of languages designed at the MIT AI lab; the first two were Planner and Conniver. The third was going to be called Schemer, but ITS only allowed 6-character filenames (because, encoded in sixbit, that fits i
68.
by thequux 3y ago
The pipe isn't broken, though; at least not until the second echo terminates. The kernel doesn't know that echo will never read stdin, because echo is generally a very simple program that doesn't bother closing unused file de
69.
by thequux 3y ago
In fact, he answered his own question. Still brilliant though
70.
by thequux 3y ago
Normally, the filesystem wouldn't directly twiddle the disk hardware; even on the PDP-11, you had a bewildering array of disk types: fixed head RC disks, single platter RL01/RL02, multi-platter RK01-RK07, RP disks that were a some
71.
by thequux 3y ago
The 11/70 had a 22-bit wide memory bus and an 18-bit wide unibus which was mapped to the high 256kb of the 4M physical address space.
72.
by thequux 3y ago
This seems to be a social problem masquerading as a technological one: recording devices that transmit what they hear are a dual-use technology. Just as an abuser might use such a bug to prevent their partner from seeking help, so might an
73.
by thequux 3y ago
Mainframes don't buffer keystrokes at all: rather, they send a screen to the terminal with marked "fields", and then the terminal handles all keystrokes until you press return or one of the attention keys to submit the change
74.
by thequux 3y ago
That clause (which was a more general restriction on use in safety-critical systems) was definitely part of the Java EULA pre-OpenJDK, but I'd imagine that it was more widespread. As I understand it, it was very much a liability issue
75.
by thequux 3y ago
The accelerometer exactly matches wheel rotation rate when you are driving in a straight line on a planar surface[1] in a vehicle with no toe. This is rarely the case: roads aren't perfectly flat, and outside of North America, aren&#
76.
by thequux 3y ago
Keep in mind that when the CISC vs RISC distinction was coined, the predominant architectures were things like IBM System/370 and VAX. System/370 has an instruction that inserts an item into a heap. (and modern Z/Architecture
77.
by thequux 3y ago
In a small sense, doing yet another data migration in a long line of data migrations. The data I had was a collection of proprietary test results about electronic parts, half hand-entered and half generated by various tools some of which da
78.
by thequux 3y ago
Yes, you can do this in ways other than conditions. However, I disagree with basically every objection you raise. First, the decision made by the handler case doesn't necessarily care which file the error was in, what the line number i
79.
by thequux 3y ago
Indeed. For those who aren't familiar with the concept, you can consider them as the logical conclusion of exceptions. Traditional error handling, as found in C for example, forces you to handle the error at the moment you detect it. O
80.
by thequux 3y ago
Fortran 56's IF statement is very different from the Lisp if statement; the former is a conditional jump, and the latter is a structured control flow construct. Further, Fortran 56's DO isn't a do/while loop as we know
81.
by thequux 3y ago
It is absolutely possible to run AIX and IBM i in separate LPARs on the same machine (as of Power 7, at least), as long as you have the appropriate hardware entitlement to run IBM i.
82.
by thequux 3y ago
I only know of two operating systems where IP address parsing (and the address resolver in general) is part of the TCP/IP stack: ITS and z/OS. MS-DOS gets an honorable mention due to not having any architectural distinction betwee
83.
by thequux 3y ago
While I'm all for reducing download sizes, perhaps lekktor[1] is a bridge too far. [1]: https://fgiesen.wordpress.com/2012/04/08/metaprogramming-for...
84.
by thequux 4y ago
Quite some time ago (~15 years?), I needed to repeatedly recompile SBCL from scratch, a process that produced multiple megabytes of output per second. I found that the gnome-terminal (which I was using at the time) increased compile time by
85.
by thequux 4y ago
I'll add one: An address with an apartment letter may not be the same building as the same address without the apartment letter. My address is something like "Bijvorbeeldstraat 3B". Next door, in a separate building, is &quot
86.
by thequux 4y ago
You was always both singular and plural, but in the singular form it was the formal second person pronoun, whereas thou was the second person singular informal pronoun; it's the same as the difference between du/Sie in German, t
87.
by thequux 4y ago
Only in the UK. In the US, it's better known as a Line Degree.
88.
by thequux 4y ago
Exceptions reflect the realization that the proper place to handle an error is generally not where the error itself occurs. The problem with exceptions (and error returns, for that matter) is that the best place to handle an error is also
89.
by thequux 4y ago
Actually, ln takes arguments in the same order as cp and mv. It's always `cmd existing-file... new-name`. ln only gets confusing because the file that exists is the target of the link, so it may be natural to think of the link as going
90.
by thequux 4y ago
I run my HMC in a VM running in libvirtd. IIRC, IBM provided the image as a VMware appliance, but it was quite simple to convert to something open source (at the cost of being an unsupported configuration, but it's not as if I could af

More ›