Wikipedia:Reference desk/Archives/Computing/2018 September 27

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September 27

So there's 2 types of 0's and 1's?

Can anyone provide feedback on there being 2 types of 0's and 1's in the motherboard. The 2 types being:

Spinning hard disks use magnetic orientation to encode 0/1 patterns.

And.

Solid state drives and DRAM use electric charge (or no charge) to encode 0/1 patterns.

So you have to have a device that can interpret both types? I'm looking into how the motherboard translates machine language. Thanks. 12.239.13.143 (talk) 00:34, 27 September 2018 (UTC).

Actually there may be many more ways to encode 0's or 1's. They could be due to a voltage transition, or could be coded by a change in magnetism, multiple voltage levels, or even more complex codings. Mostly these differences will be handled by hardware or microcode in the device. A number of standards are used so that a device can send the data on the motherboard to the device, CPU or memory in a way that every thing can cope with. The hardware will convert from the internal code to the standard as used on the bus. see for example PCI Express, I²C, or USB. Graeme Bartlett (talk) 05:58, 27 September 2018 (UTC)

Note that nearly all consumer SSDs released in the past 4? or more years use Multi-level cell, generally triple in the past year or so, meaning that more than one bit is stored in a cell via multiple voltage levels. While still very rare, some computers generally fancy servers may have devices with 3D XPoint which uses resistance. Some computers still have Optical disc drives. While often only used for data accessed temporarily or moved around (including backups), people sometimes may regularly use live CD/DVDs for their OS. While both CDs and DVDs (and most other Optical discs) are generally described to use pits and lands, in reality it's a little more complicated than that. Pressed discs do involve basically stamping pits onto the disc (see Compact Disc manufacturing), although the surface next to the reflective side (not the side you can touch as sometimes believed). But recordable discs (CD-R, DVD-R, DVD+R etc) generally involve changing the properties of a dye layer. Rewritable discs (CD-RW, DVD-RW, DVD+RW, DVD-RAM) use a phase-change material. But these are basically all read in the same way, sensing how a laser is reflected back. (Writing recordable and re-writeables also occurs using very similar operations.) Nil Einne (talk) 16:07, 27 September 2018 (UTC)

It's not clear whether the OP is asking about different methods of storage or encoding. One method of encoding (NRZI) is that a 1 (or 0) is chosen to represent only the change from one state to the other, rather than the actual data bit value. The reading device must decode this in order to pass it along. Akld guy (talk) 21:05, 27 September 2018 (UTC)

ARM Cortex R52

Does anyone actually make an ARM Cortex R52[1] chip that I can buy? The only thing I could find is the NXP S32S24[2] but that one is preproduction. --Guy Macon (talk) 22:07, 27 September 2018 (UTC)

This suggests STMicroelectronics have provided samples of their platform to one customer [3]. This source suggests the codename Stellar and sampling this year but not sure if this means more widely than that one customer [4]. (I think the second source is using one of those weird American dates which puts the month then the day then the year so it's dated before the first.) So select people can obtain them, possibly more later. I'm guessing if you had access to those sort of resources you wouldn't be asking here though. Nil Einne (talk) 22:42, 27 September 2018 (UTC)

This is for a side project. The sad part is that if I told them that I do consulting for Mattel (true, but I am not on a Mattel project right now) and that I needed this for a Mattel project (a complete lie; we use much lower cost microcontrollers) they would fall over themselves assisting me. Damn these inconvenient ethics! :) --Guy Macon (talk) 02:28, 28 September 2018 (UTC)

Importing csv into OpenOffice dbase

Hi there. I'm trying to import records from csv to dbase (OpenOffice). I'm trying to follow instructions here:

https://forum.openoffice.org/en/forum/viewtopic.php?f=83&t=23260 (search for "This type of connection can be created if you follow this steps:")

It works fine if I use his csv:

ID,FirstName,Name,DOB
1,John,White,1960-01-23
2,Elisabeth,Smith,1972-11-10
3,Eric,Long,1987-04-07

But not if I use mine:

ID,Name,Status1,Status2,Phone
9018,linda,0,1,123123123123
9019,jenny,0,1,123123123123
9020,luke,0,1,123123123123
9021,mark,0,1,123123123123

How do I modify his line:

CREATE TEXT TABLE "Names" ("ID" INTEGER PRIMARY KEY, "FirstName" VARCHAR(20), "Name" VARCHAR(20), "DOB" DATE);

...so that it will work for my csv?

Many thanks for any help you can offer.

Anna Frodesiak (talk) 22:23, 27 September 2018 (UTC)

Never mind. I finally figured it out. Thanks anyhow. :) Anna Frodesiak (talk) 01:03, 28 September 2018 (UTC)

(ec) I was about to suggest:

CREATE TEXT TABLE "Names" ("ID" INTEGER PRIMARY KEY, "Name" VARCHAR(20), "Status1" BOOLEAN, "Status1" BOOLEAN, "Phone" VARCHAR(20));

This assumes that the status values are booleans (0/1 = false/true) and treats the phone number as text. Glad you figured it out. -- Tom N talk/contrib 01:14, 28 September 2018 (UTC)

Hi Tom. Actually, I didn't figure it out after all. I did get my stuff into the dbase, but now I cannot make the primary key stick and cannot add new entries to the table. Is there no way to do this? It's driving me nuts. Anna Frodesiak (talk) 07:14, 28 September 2018 (UTC)

As the ID colmn is a primary key, its unique per line/record and required. First enter a not existing number in the ID field, then follow the other fields. --Hans Haase (有问题吗) 20:29, 29 September 2018 (UTC)

Hi Hans Haase. Thank you kindly. Actually, I was looking for a way to take the records from a csv and add them all at once to the dbase. For some odd reason, that does not seem possible. Anyhow, I've added them by hand. Thank you both anyway. :) Anna Frodesiak (talk) 20:59, 29 September 2018 (UTC)

Hi, a primary key resets by reorganizing/recompressing the data base or drop and recreate the table. Base is a bit difficulty to handle. When taking calc to import and transfer the table from CSV? Success? --Hans Haase (有问题吗) 21:03, 29 September 2018 (UTC)

Hi Hans Haase. I think I understand about primary keys. I just figured, as long as that column in csv is full of unique numbers, importing into dbase ought to be doable. Strange that it isn't. Also, there doesn't seem to be any way to even copy paste columns of data into an existing table. But all that doesn't matter now. I've done it all manually. Best, Anna Frodesiak (talk) 21:29, 29 September 2018 (UTC)

I figured it out for anyone in the future having trouble with this:

You don't need to save the spreadsheet in csv. You just need to highlight the columns in the spreadsheet, then in dbase/tables, right click on the empty space in the tables pane and click paste. That will make a table out of the spreadsheet column. If you allow it to make a primary key, then it becomes a usable table you can add to. Anna Frodesiak (talk) 06:49, 30 September 2018 (UTC)