In SMS text mode, the syntax of the +CMGS AT command is: (Optional parameters are enclosed in square brackets.)

+CMGS=address[,address_type]<CR>sms_message_body<Ctrl+z>

Before we discuss each of the parameters, let’s see an example that gives you some idea of how an actual command line should look like:

AT+CMGS=”+85291234567″,145<CR>This is an example for illustrating the syntax of the +CMGS AT command in SMS text mode.<Ctrl+z>

The address Parameter

The first parameter of the +CMGS AT command, address, specifies the destination address to send the SMS message to. Usually it is a mobile number formatted using the typical ISDN / telephony numbering plan (ITU E.164/E.163). For example, “+85291234567”, “91234567”, etc. Note that the value passed to the address parameter should be a string, i.e. it should be enclosed in double quotes.

The address_type Parameter

The second parameter of the +CMGS AT command, address_type, specifies the type of the address assigned to the address parameter. Two values are commonly used. They are 129 and 145:

• 129. It means the value of address is formatted using the typical ISDN / telephony numbering plan (ITU E.164/E.163) but it is not sure whether the value of address is an international number, a national number or a number of other types. Example addresses: “85291234567”, “91234567”.

• 145. It means the value of address is formatted using the typical ISDN / telephony numbering plan (ITU E.164/E.163) and it is an international number. Example address: “+85291234567”.

As address_type is an optional parameter, it can be omitted. If you do so, the GSM/GPRS modem or mobile phone will use the default value of the address_type parameter, which is:

• 129 if the value of address does not start with a “+” character. For example, “85291234567”.

• 145 if the value of address starts with a “+” character. For example, “+85291234567”.

http://www.developershome.com/sms/cmgsCommand.asp

https://stackoverflow.com/questions/21522794/atcmgs-returns-error

Find “SMS / MMS”

1. Press Messages.
2. Press the Menu key.
3. Press Settings.
4. Press the SMS / MMS tab.
5. Press Message Centre.
6. Key in +41794999000 and press OK.
7. Press the Home key to end the session and return to the Home screen.

http://www.developershome.com/sms/cscaCommand.asp

http://www.roundsolutions.com/forum/index.php?page=Thread&threadID=1784

http://www.smssolutions.net/tutorials/gsm/sendsmsat/

https://cristiansteib.github.io/Sim800l

• SIM800 5v/4v ↔ Arduino 5v
• SIM800 GND (either one) ↔ Arduino GND
• SIM800 SIM_TXD ↔ Arduino D8 (read through for the reason)
• SIM800 SIM_RXD ↔ Arduino D7 (read through for the reason)

Source: Quickstart SIM800 (SIM800L) with Arduino

https://en.m.wikipedia.org/wiki/Ed_Roberts_(computer_engineer)

https://en.m.wikipedia.org/wiki/Lee_Felsenstein

https://en.m.wikipedia.org/wiki/People%27s_Computer_Company

The Whole Earth Catalog (WEC) was an American counterculture magazine and product catalog published by Stewart Brand several times a year between 1968 and 1972, and occasionally thereafter, until 1998. The magazine featured essays and articles, but was primarily focused on product reviews. The editorial focus was on self-sufficiency, ecology, alternative education, “do it yourself” (DIY), and holism, and featured the slogan “access to tools”. While WEC listed and reviewed a wide range of products (clothing, books, tools, machines, seeds, etc.), it did not sell any of the products directly. Instead, the vendor’s contact information was listed alongside the item and its review. This is why, while not a regularly published periodical, numerous editions and updates were required to keep price and availability information up to date.

https://en.m.wikipedia.org/wiki/Whole_Earth_Catalog