Heading:qjk40(635)\g The Alto DLSy756qk40\g Page Numbers: Yes X: 527 Y: 10.5"qjk40\g Inter-Office Memorandumz18592l4445y762\f5bg To DLS users Date July 7, 1983 z18592l4445d2998e21(0,65535)(1,4445)(5,11684)(6,13664)\f1g2f0t2 1t0 9t6 1f1t0 4f0t7 1t0 From Ed Taft & Ron Weaver Location PARC/CSL z18592l4445d2998e25\f1g4f0t2 1t0 7t6 14f1t0 8f0t7 1t0 Subject The Alto DLS File [Indigo]DLS.press (edition 5)z21167l4445d2998e25\f1g7f0t2 1t0 12t6 1f1t0 4t7 1t0 22f0 XEROX z18592l508e14(2116)\f2g5f0 z18697l3033e10j(1270)\g We have a dedicated Alto in operation as a terminal controller or DLS (for Data Line Scanner). It serves as an interface between the Xerox Research Internet and low-speed lines (2400 baud or less) connecting to hardwired or dial-up terminals, outside timesharing services, and the like. z18697l3033e10jk40\g The DLS provides two main services:z18697l3033e10jk40\g a dial-in service, which permits outside terminals to make incoming connections (via the public telephone network or hardwired lines) and thereby gain access to servers connected to the Internet, principally Maxc, IFSs, and Ernestine; and z18697l4303e10jk40\g2i7I a dial-out service, which permits users of Altos and other computers in the Internet to make outgoing connections (via the telephone network) to external services such as timesharing systems.z18697l4303e10jk40\g2i8I There are actually several DLSs in operation at various locations in the Research Internet. Information contained in this memo applies to PARC's DLS only. z18697l3033e10jk40\g140f1 3f0 1. Dial-in servicez18697l3033e22k80\bg18B To access the DLS from an outside terminal, you dial an appropriate phone number (see below), connect the terminal, and issue commands to a DLS executive, which will in turn make connections over the Xerox Research Internet to servers such as Maxc. z18697l3033e10jk40\g140i13I When you initially make contact with the DLS, it first waits for you to type a single character, from which it deduces the speed of your terminal and determines what to do next. You must type one of: CTRL-C, E', e', or RETURN. The DLS then prints the greeting message: z18697l3033e10jk40\g201f1 4f0 17f1 6f0 PARC DLS #n >z18697l4303e10jk40\g1f1 3f0 6i1I where n is a number identifying the line to which you are connected. z18697l3033e10jk40\g6i1I If the character you typed was CTRL-C, the DLS then immediately attempts to make a network connection to the default server host for your DLS line (which on PARC's DLS is usually Maxc). If this is successful, your terminal is logically connected to that server, with no further action on your part.z18697l3033e10jk40\g31f1 4f0 123f1 3f0 If the initial character you typed was E', e', or RETURN, or the automatic attempt at connecting to the default server was unsuccessful, you are left talking to a simple DLS executive, whose prompt is >' at the left margin, and whose commands are described in the next section. z18697l3033e10jk40\g52f1 6f0 While you have a connection open to a server, you can also give control to the DLS executive by typing the escape character, which is initially ASCII code 036 (CTRL-period on TI-700 terminals, CTRL-^ or CTRL-SHIFT-N on most others). z18697l3033e10jk40\g107i6I32f1 4f0 11f1 4f0 29f1 4f0 6f1 4f0 1f1 5f0 If you hang up while you have a network connection open to a server, that connection is automatically broken. If the server you were connected to is Maxc, this has the effect of causing your job to be detached; for other servers, your session is terminated. z18697l3033e10jk40\g It may happen that your network connection to the server will fail in any of a variety of ways. Usually a self-explanatory message, such as [Pup error] Tenex restarting, wait'', will be printed out. If server or network problems cause communication to fail completely, the message [Connection timed out]'' will be printed within one minute, and you will be left talking to the DLS executive.z18697l3033e10jk40\g Phone numbers and modem typesz18697l3033e16k80\ig29I The DLS is accessible via several different phone numbers, reflecting the following variations in service:z18697l3033e10jk40\g Most phone numbers are located in the Palo Alto exchange, but a few are located in the San Jose exchange so as to be reachable by a local call from the South Bay area. z18697l4303e10jk40\g Most of the lines connect to 300-baud modems, but some connect to 1200-baud modems. The 300-baud modems are compatible with all types of terminals operating at 300, 150, or 110 baud (30, 15, or 10 characters per second). The 1200-baud modems are compatible only with Vadic 3400-series modems or couplers (and, in particular, are incompatible with Bell 212 or UDS modems). z18697l4303e10jk40\g When you type CTRL-C as the initial character, the DLS decides what server to connect to (usually Maxc) based on which DLS line you are using. (Of course, you can override this default by instead typing RETURN as the initial character and issuing the Connect host' command, described in the next section.) z18697l4303e10jk40\g14f1 4f0 186f1 6f0 51i4I Complete information on phone numbers is given in a table at the end of this memo. Here is a summary of the most useful numbers: z18697l3033e10jk40\g Exchange Modem Default Number Phone number type host of linesz18697l4303e10jk40(0,7488)(1,9696)(2,12032)(3,14368)(5,65535)(6,65535)\ig62I Palo Alto 300 Maxc 7 (415) 493-3121z18697l4303e10j(2,12576)\g Palo Alto 1200 Maxc 5 (415) 493-3105z18697l4303j\g San Jose 300 Maxc 2 (408) 279-8488z18697l4303j\g San Jose 1200 Maxc 1 (408) 279-3166z18697l4303j\g DLS dial-in executive commandsz18697l3033e16k80(1270)\ig30I The DLS executive has a very simple command structure. All commands are specified by a single letter, and the DLS then types the remainder of the command word. Most commands require you either to supply an argument or to confirm by typing RETURN. While typing an argument, you may delete characters by typing BS or CTRL-A, or cancel the entire command by striking DEL. z18697l3033e10jk40\g241f1 6f0 65f1 2f0 4f1 4f0 45f1 3f0 Byez18697l4303e10jk40\ug1U Closes your current network connection, if one is open, and then prints Line n off''. Your line then reverts to its initial state in which it is expecting you to type one of the initial characters (for speed determination). Hence Bye' is equivalent to hanging up and dialling in again. This is useful if you want to switch your terminal to a new speed. z18697l4864e4j\g79i1I Connect to: hostz18697l4303e10jk40\ug1U11ui4UI Attempts to establish a connection to the specified server. Usually host is simply the name of a server host (e.g., Maxc'), but any Xerox Internet name or address expression is legal. z18697l4864e4j\g69i4I Disconnectz18697l4303e10jk40\ug1U Closes your current network connection, if one is open. z18697l4864e4j\g Escape character = cz18697l4303e10jk40\ug1U18ui1UI Changes your escape character to c, where c may be whatever character you type in (RETURN and DEL are not permitted). Initially the escape character is CTRL-^ (ASCII 036B).z18697l4864e4j\g33i1I8i1I40f1 6f0 5f1 3f0 56f1 4f0 5f1 4f0 4f1 1f0 Flush typein streamz18697l4303e10jk40\ug1U Discards all characters you have typed but that have not yet been consumed by the server at the other end of the open connection. This is useful if you have lost control of the server due to having typed ahead more characters than the combined buffering capacity of the server and the DLS. z18697l4864e4j\g Grapevinez18697l4303e10jk40\ug1U Makes a connection to a Grapevine unintelligent terminal server (Ernestine''). No confirming RETURN is required. z18697l4864e4j\g96f1 6f0 Local echoing on/offz18697l4303e10jk40\ug1U Ordinarily, when your terminal is logically connected to a server (e.g., Maxc), that server provides echoing of characters you type. This command toggles a switch that determines whether or not the DLS is to echo characters locally. The default state of the switch is off'.z18697l4864e4j\g Resume connectionz18697l4303e10jk40\ug1U Resumes your terminal's logical connection to the server (if there is one). You use this command after having typed the escape character and issued other DLS executive commands (except Disconnect). z18697l4864e4j\g Versionz18697l4303e10jk40\ug1U Prints the version and release date of the DLS control program. z18697l4864e4j\g ?z18697l4303e10jk40\ug1U Prints the list of commands. z18697l4864e4j\g Hardwired linesz18697l3033e16k80\ig15I There are 16 lines that are hardwired to terminals in people's offices; terminals currently connected include TI-700, Tektronix 4023, and DataMedia 3000. The number of hardwired lines is strictly limited to 16, so if you want one you must negotiate with some present owner. z18697l3033e10jk40\g Operation of the DLS through hardwired lines is the same as through dial-in lines except that you never dial in, data rates of up to 2400 baud (240 characters per second) are accepted, and certain parameters (default host, terminal type, screen dimensions) may be preset on a per-line basis. z18697l3033e10jk40\g 2. Dial-out servicez18697l3033e22k80\bg19B The dial-out service enables you to make outgoing connections through the DLS from your Alto. This service is presently being provided without any controls or accounting, and all phone charges are billed to PARC. It is our hope that this arrangement will prove adequate and will not be abused.z18697l3033e10jk40\g209f1 3f0 If you intend to use the dial-out service, please send a message to Ron Weaver before using it for the first time. You should be aware of the following points: z18697l3033e10jk40\g The principal intended clients for this service are the PARC librarians, who depend on it very heavily in their day-to-day operation. There are only three 300-baud and five 1200-baud dial-out lines (the latter are also the only Palo Alto 1200-baud dial-in lines). Extensive use of this service by other users may require negotiation to avoid conflict with the library.z18697l4303e10jk40\g57f1 3f0 Calls originate in Palo Alto, and are charged at regular business phone rates. Please refrain from making calls outside the Palo Alto calling area unless absolutely necessary. z18697l4303e10jk40\g How to use itz18697l3033e16k80\ig13I You access the DLS dial-out service by running Chat on your Alto and making a connection to the DLS. Assuming you have Chat.run on your disk, simply type: z18697l3033e10jk40\g >Chat ParcDLS+300 RETURN to access a 300-baud line, or >Chat ParcDLS+1200 RETURN to access a 1200-baud line.z18697l4303e10j(0,10624)(1,65535)(2,65535)(3,65535)\g1u16U1f1o4u6f0o0UG32u5g4G8U1f1o4u6f0o0U28g If the DLS is operating normally, you will shortly see the message: z18697l3033e10jk40(1270)\g PARC DLS dial-out server, line n (b baud) >z18697l4303e10j\g31i1I2i1I If all the dial-out lines of the speed you requested are in use, Chat will display a message to that effect and will not complete the connection to the DLS. z18697l3033e10jk40\g The dial-out server has a simple executive with a small number of single-character commands. When you see >' at the left margin, the DLS executive is waiting for you to type a command. Now type:z18697l3033e10jk40\g >Call phone number xxx-xxxx RETURNz18697l4303e10j\g1u1U17ui8UI1f1o4u6f0o0U that is, C' followed by the phone number you want to dial, terminated by RETURN. The DLS will proceed to dial the number. z18697l3033e10jk40\g74f1 6f0 If the call is answered and the correct answering tone is heard, the DLS will display the message Call completed'', perhaps followed by a greeting from the computer system you called. Thereafter, all characters you type will be sent over the phone connection, and all characters received over the phone connection will be displayed on your Alto screen. z18697l3033e10jk40\g If the number you dialled is busy or doesn't answer within 30 seconds, the message Failed to complete connection'' will appear, and control will return to the DLS executive. Unfortunately, the DLS can't distinguish between the busy and no-answer conditions. Problems other than busy and no-answer will result in the message Dialler or phone system malfunction''. z18697l3033e10jk40\g To terminate the connection, first log out from the remote computer in whatever way is appropriate. The easiest next step is simply to Quit out of Chat (with BLANK-MIDDLE Q or SHIFT-SWAT). This both hangs up the DLS dial-out line and breaks the connection between your Alto and the DLS. z18697l3033e10jk40\g159f1 12f0 6f1 10f0 You can also return control to the DLS executive by typing CTRL-_ (CTRL-left-arrow), then break the connection using the Disconnect command, described in the next section. z18697l3033e10jk40\g59f1 4f0 4f1 4f0 If the phone connection is broken because the remote computer hangs up, the message Dial-out connection broken'' is displayed and control returns to the DLS executive. z18697l3033e10jk40\g Dial-out server executive commandsz18697l3033e16k80\ig34I You can type any of the following commands when you see >' at the left margin. You must terminate all commands with RETURN. z18697l3033e10jk40\g118f1 6f0 Baud rate = numberz18697l4303e10jk40\ug1U11ui6UI Sets the speed of the dial-out connection. Only 300-baud lines may have their speed changed in this manner, and legal values are 300, 150, and 110. z18697l4864e4j\g Call phone number numberz18697l4303e10jk40\ug1U17ui6UI Dials the phone number you specify, as described above. The phone number may be up to 15 digits long. The forms nnn-nnnn' and (nnn) nnn-nnnn' are accepted, or you may type the entire phone number without punctuation. (In fact, parentheses and hyphens are simply ignored.) z18697l4864e4j\g115i8I8i3I2i8I Disconnectz18697l4303e10jk40\ug1U Breaks the dial-out connection, by hanging up the phone line. Control remains in the DLS executive. z18697l4864e4j\g Escape character = cz18697l4303e10jk40\ug1U18ui1UI Changes your escape character to c, where c may be whatever character you type in (RETURN and DEL are not permitted). Initially the escape character is CTRL-_ (ASCII 037B).z18697l4864e4j\g33i1I8i1I40f1 6f0 5f1 3f0 56f1 4f0 5f1 4f0 4f1 2f0 Quitz18697l4303e10jk40\ug1U Breaks the dial-out connection (if there is one), and then breaks the connection between your Alto and the DLS dial-out server. z18697l4864e4j\g Resume connectionz18697l4303e10jk40\ug1U Resumes your dial-out connection (if there is one). You use this command after having typed the escape character and issued other DLS executive commands (except Disconnect).z18697l4864e4j\g Other notesz18697l3033e16k80\ig11I To capture your dialog in a file, enable the Chat typescript feature by typing MIDDLE-BLANK T followed by a file name and RETURN. When you are done, type MIDDLE-BLANK T RETURN to close the typescript file; or alternatively just Quit from Chat. The typescript file will be on your Alto disk, and you can edit it, print it, etc., in the usual fashion. (Alternatively, you can specify a Chat typescript file by an appropriate entry in your User.cm.) Further information about Chat may be found in the Alto Non-programmer's Guide and in the Chat documentation (file Chat.tty). z18697l3033e10jk40\g79f1 12f0 31f1 6f0 27f1 12f0 3f1 6f0 You can get the DLS dial-out server to generate a long space'' by typing CTRL-SPACE on your Alto keyboard; this is equivalent to pressing the BREAK key on ordinary terminals. z18697l3033e10jk40\g75f1 10f0 59f1 5f0 You can connect to a specific DLS line by means of the command Chat ParcDLS+1000xx'', where xx is the desired line number. At present, the main use of this feature is connecting to GSL's Vax computer, which is hardwired to DLS line 13 (i.e., ParcDLS+100013), and to CSL's WWV time receiver, which is on line 15 (ParcDLS+100015).z18697l3033e10jk40\g82i2I10i2I 3. Current configuration, phone numbers, etc.z18697l3033e22k80\bg45B The DLS line configuration changes occasionally; its current state is given in file [Indigo]ParcDLS.config, which is a text file that is read by the DLS control program to determine how it is to treat each line. This file specifies terminal parameters, phone numbers for dial-in lines, and owners and office numbers of hardwired lines. A copy of this file appears below.z18697l3033e10jk40\g Contents of DLS.config, as of July 7, 1983z18697l3033e16k80\ig42I // Hardwired lines 00 Hardwired Host Maxc // Maxc room 01 Hardwired Host Maxc // Maxc room 02 Hardwired Host Maxc Type 10 Length 24 Width 80 // 35-3212 A. Wilder 03 Hardwired Host Maxc Type 10 Length 24 Width 80 // 35-3550 L. Anderson 04 Hardwired Host Maxc // 35-1014 & 1344 Cheng 05 Hardwired DialOutOnly Baud 1200 // 35-2176 Swinehart 06 Hardwired DialOutOnly Baud 1200 // 35-2110 Larry Stewart 07 Hardwired DialOutOnly Baud 1200 // 10 Hardwired Host Maxc Type 10 Length 24 Width 80 // 35-2102 M. Kay 11 Hardwired Host Maxc Type 10 Length 24 Width 80 NoPad // 35-2116 Tim Diebert 12 Hardwired Host Maxc Length 24 Width 80 // 35-2328 Glen Williams - ISL 13 Hardwired DialOutOnly Baud 1200 // 35-1126 Vax 14 Hardwired Host Maxc Type 10 Length 24 Width 80 // 35-Receptionist 15 Hardwired DialOutOnly Baud 2400 // 35-2106 WWV receiver 16 Hardwired DialOutOnly Baud 1200 // 35-2234 EtherPhone 17 Hardwired Host Maxc // 35-2148 Taft // The following are 300-baud, dial-in only, San Jose exchange 23 Dataset Control 43 Host Maxc // (408) 279-8489 rotary [2] 24 Dataset Control 44 Host Maxc // (408) 279-8488 rotary [1] // The following is 1200-baud, dial-in only, San Jose exchange 25 Dataset Control 45 Host Maxc // (408) 279-3166 // The following is 300-baud, dial-in or dial-out, Palo Alto exchange // (more of these below) 26 Dataset Control 46 DialOut 15 1 Host Maxc // (415) 493-2130 // (415) 493-3128 rotary [8] not currently connected to the DLS // The following are 300-baud, dial-in only, Palo Alto exchange 31 Dataset Control 51 Host Maxc // (415) 493-3127 rotary [7] 32 Dataset Control 52 Host Maxc // (415) 493-3126 rotary [6] 33 Dataset Control 53 Host Maxc // (415) 493-3125 rotary [5] 34 Dataset Control 54 Host Maxc // (415) 493-3124 rotary [4] 35 Dataset Control 55 Host Maxc // (415) 493-3123 rotary [3] 36 Dataset Control 56 Host Maxc // (415) 493-3122 rotary [2] 37 Dataset Control 57 Host Maxc // (415) 493-3121 rotary [1] // 40-57 control lines for the above // Dialler control lines 60 Dialler CRQ 61 Dialler DP 62 Dialler NB1 63 Dialler NB2 64 Dialler NB4 65 Dialler NB8 // The following are 300-baud, dial-in or dial-out, Palo Alto exchange // (another of these above) 66 Dataset Control 67 DialOut 12 1 Host Maxc // (415) 493-1563 70 Dataset Control 71 DialOut 11 1 Host Maxc // (415) 493-1510 // The following are 1200-baud, dial-in or dial-out, Palo Alto exchange 27 Dataset Control 47 DialOut 1 0 Host Maxc // (415) 493-3129 rotary [5] 30 Dataset Control 50 DialOut 3 0 Host Maxc // (415) 493-3104 rotary [4] 72 Dataset Control 73 DialOut 9 0 Host Maxc // (415) 493-3139 rotary [3] 74 Dataset Control 75 DialOut 7 0 Host Maxc // (415) 493-3107 rotary [2] 76 Dataset Control 77 DialOut 5 0 Host Maxc // (415) 493-3105 rotary [1]z21167(0,14111)\f1