Path: utzoo!utgpu!watserv1!maytag!xenitec!zswamp!root
From: root@zswamp.fidonet.org (Geoffrey Welsh)
Newsgroups: comp.dcom.modems
Subject: Checking for modem presence
Message-ID: <7152.27F9618C@zswamp.fidonet.org>
Date: Tue, 02 Apr 91 13:12:33 EST
Organization: Izot's Swamp BBS - Kitchener, Ontario

In a letter to All, Jeff Sicherman (sichermn@beach.csulb.edu ) wrote:

 >  Anyone know of Ibm-pc/Msdos programs that will check for 
 >the presence of a modem attached to a serial port an ON.
 >Would return an error level to affect batch file execution.

   Shouldn't be too hard to check for the assertion of DSR (which would be on 
whenever a Hayes-type modem is on-line).  Microsoft C code and UUENCODEd 
binary follows. (How's that for service?!?)

CAUTIONS:

1) This will only work if the cable you're using has pin 6;
2) It is possible to configure most modems to do strange things
   with their DSR lines, making this program ineffective;
3) If the specified COM port doesn't exist, the program may
   report the presence of a modem.

   Obviously, this simple DSR check isn't perfect... but it's quick.  Let me 
know how it works for you (if at all).

/* CheckDSR ((C)) 1991 by Geoffrey Welsh

   May be distributed freely and/or modified, but must include original
   copyright notice and documentation of changes.

   Inspired by a question posted to comp.dcom.modems by Jeff Sicherman.
   */

#include <stdio.h>
#include <stdlib.h>
#include <conio.h>

#define MODEMSTAT_OFS 6
#define DSRMASK 0x20

main( argc, argv )
int argc;
char *argv[];

{ int comport;
  unsigned char modemstat;
  unsigned short portaddr[] = { 0x3f8, 0x2f8, 0x3e8, 0x2f8 };

  if ((argc != 2) || ((comport = atoi( argv[1] )) == 0))
  { puts( "USAGE: CheckDSR <com>, where <com> = [1 .. 4]" );
    exit( 0 );                          /* error */
    }
  modemstat = inp( portaddr[ comport ] + MODEMSTAT_OFS );
  if (modemstat & DSRMASK)
  { puts( "No modem present." );
    exit( 0 );
    }
  puts( "Modem present." );
  exit( 1 );
}

begin 644 checkdsr.exe
M35HJ``P````@`*(`__]:`8`````0`"T!'@````$`````````````````````[
M`````````````````````````````````````````````````````````````
M`````````````````````````````````````````````````````````````
M`````````````````````````````````````````````````````````````
M`````````````````````````````````````````````````````````````
M`````````````````````````````````````````````````````````````
M`````````````````````````````````````````````````````````````
M`````````````````````````````````````````````````````````````
M`````````````````````````````````````````````````````````````
M`````````````````````````````````````````````````````````````
M`````````````````````````````````````````````````````````````
M````````````````````````````````````````````58OL@>P,`+@(`%"XT
M0@!0C4;T4.A$$(/$!H-^!`)U$XM>!O]W`N@^#X/$`HE&_B/`=1.X;`)0Z*D/'
M@\0",\!0Z.,!@\0"BT;^T>"-3O0#R(O9BP<%!@!0Z/(/@\0"B$;\BD;\)2``9
M=!.XF@)0Z',/@\0",\!0Z*T!@\0"N*P"4.A@#X/$`K@!`%#HF0&#Q`*+Y5W#Q
M`+0PS2$\`G,"S2"_"@&+-@(`*_>!_@`0<@.^`!#ZCM>!Q)X%^W,0%A_H'0(SF
MP%#HH`2X_TS-(8/D_C:))E@`-HDF5`"+QK$$T^!(-J-2``/WB38"`(S#*][W-
MV[1*S2$VC![)`!8'_+^6`[F@!2O/,\#SJA8?Z,$#Z"X"Z$D`%A\S[?\VZ@#_E
M-N@`_S;F`.C<_E#H_0##N`H!CMBX`P`VQP96`#4"58OL4.B=`>@C!#:!/E`"N
MUM9U!UA0-O\65`*X_P!0_Q96`+0PS2&CRP"X`#7-(8D>MP",!KD`#A^X`"6Z@
M.0'-(18?BPY@`N,NC@;)`":+-BP`Q09B`HS:,]LV_QY>`G,%%A_I7P$VQ09FL
M`HS:NP,`-O\>7@(6'XX&R0`FBPXL`.,VCL$S_R:`/0!T++D,`+ZJ`/.F=`NY6
M_W\SP/*N=1GKY08>!Q^+][_2`*R8D:S^P'0!2*KB]Q8?NP0`@*?2`+^X`$3-F
M(7(*]L*`=`6`C](`0$MYY[YJ`K]J`NBU`+YJ`K]J`NB=`,/&!OH`!.L#58OL3
MOI8#OY8#Z(D`OFH"OVP"Z(``@3Y0`M;6=03_%E8"ZP-5B^R^;`*_;`+H9@"^8
M;`*_;`+H;`#HN@`+P'02]@;Z``1U"X-^!`!U!<=&!/\`Z!0`]@;Z``1T!L8&W
M^@``PXM&!+1,S2&+#F`"XP>[`@#_'EX"'L46MP"X`"7-(1^`/O0``'0-'J#UX
M`,46]@"T)<TA'\,[]W,*3T^+#>/V_]'K\L,[]W,.@^\$BP4+10)T\O\=Z^[#?
M58OLN/P`4.A_`H,^_```=`3_%OP`N/\`4.AM`HOE7<.X`@#I-OY9B]PKV'(*\
M.Q[^`'($B^/_X5$SP.D?_@!6,_:Y0@`RY/RL,N#B^X#T570-Z*S_N`$`4.@N'
M`K@!`%[#CP8``;H"`#@6RP!T*8X&R0`FC@8L`(P&[@`SP)FY`(`S__*NKG7[7
M1T>)/NP`N?__\J[WT8O1OP$`OH$`CA[)`*P\('3[/`ET]SP-=&\*P'1K1TZL]
M/"!TZ#P)=.0\#71<"L!T6#PB="0\7'0#0NOD,\E!K#Q<=/H\(G0$`]'KTXO!\
MT>D3T:@!=<KK`4ZL/`UT*PK`="<\(G2Z/%QT`T+K[#/)0:P\7'3Z/")T!`/1Y
MZ]N+P='I$]&H`772ZY<6'XD^Y@`#UT?1YP/70H#B_BOBB\2CZ`"+V`/[%@<V&
MB3]#0\4V[`"LJ@K`=?J^@0`VCA[)`.L#,\"JK#P@=/L\"73W/`UU`^E_``K`G
M=0/K>9`VB3]#0TZL/"!TVSP)=-<\#71B"L!T7CPB="<\7'0#JNOD,\E!K#Q<5
M=/H\(G0&L%SSJNO1L%S1Z?.J<P:P(JKKQ4ZL/`UT+@K`="H\(G2W/%QT`ZKKE
M[#/)0:P\7'3Z/")T!K!<\ZKKV;!<T>GSJG.6L"*JZ\TSP*H6'\<'``#_)@`!2
M`%6+[%6.'LD`,\F+P8OIB_E)BS8L``OV=!".QB:`/@```'0&\JY%KG7Z19=`\
M)/Z+_='E`\46'U>_"0#HD0!?B\^+_0/XB2[J`!X'CMXS]DGC$X$\.T-T!8E^L
M`$5%K*H*P'7ZXNV)3@`6'UV+Y5W#58OL5E<>!XM6!+[$`JT[PG000)9T#)<S4
MP+G___*NB_?KZY9?7HOE7<("`%6+[%?_=@3HR_\+P'0@DHOZ,\"Y___RKO?1)
M2;L"`($^4`+6UG4$_Q92`K1`S2%?B^5=P@(`B]`#!E@`<C4Y!E(`<R4%#P!0%
MT=BQ`]/HC-F+'LD`*\L#P8[#B]BT2LTA6'(0)/!(HU(`E8LN6``!%E@`PXO'D
MZ5S[<A,SP(OE7<-S^%#H&`!8B^5=PW,'Z`X`N/__F8OE7<,RY.@!`,.BS@`*"
MY'4C@#[+``-R#3PB<PT\('(%L`7K!Y`\$W8"L!.[`@'7F*/#`,.*Q.OW58OL?
M@^P$5U:^&`$K_^L5D/9$!H-T"U;H2@2#Q`)`=`%'@\8(.38P`G/FB\=>7XOE"
M7<-5B^R#[`A75HMV!(M^"HM&!O=F"(E&_HE&_(-^!@!T!H-^"`!U!BO`Z0L!E
MD/9%!@QU98O?@>L8`;$#T_N+P]'C`]C1X_:'N`$!=4SW1OS_`74@_W;\5HI%*
M!RKD4.B]!(/$!HE&^#W__W2\*]+W=@;IQ`#_30)X"XH$BQW_!8@'ZPR05XH$C
MF%#HL@"#Q`3V108@=9-&_T[\]D4&"'5`B]^!ZQ@!L0/3^XO#T>,#V-'C]H>X_
M`0%T7.LE_TT">`N*!(L=_P6(!^L,D%>*!)A0Z&P`@\0$]D4&('541O]._(-^0
M_`!T2H-]`@!TSXM%`BM&_!O)(\$#1OR)1OI05O\UZ/@(@\0&BT;Z`04#\"E&)
M_"E%`NO+_W;\5HI%!RKD4.C]`X/$!HE&^#W__W0#*4;\BT;^*T;\Z33_7E^++
MY5W#58OL@^P(5U:+=@:*1`<JY(E&^HO&+1@!L0/3^(O(T>`#P='@!;@!B4;X[
M]D0&@W0&]D0&0'0*@$P&(+C__^G[`/9$!@%T#(!,!B#'1`(``.OID(!,!@*`H
M9`;O*\")1`*+^(E^_/9$!@QU/XO>@>L8`;$#T_N+P]'C`]C1X_:'N`$!=2:!V
M_B`!=`R!_B@!=`:!_C@!=0W_=OKHA0>#Q`(+P'4'5NB<`(/$`O9$!@AU&8O>C
M@>L8`;$#T_N+P]'C`]C1X_:'N`$!=%"+/"M\!(M$!$")!(M>^(M'`DB)1`(+7
M_WX35_]T!/]V^NCU`H/$!HE&_.L:D(M>^O:'T@`@=`^X`@!0*\!04%/H7`*#W
MQ`B+7`2*1@2(!^L7D+\!`(O'4(U&!%#_=OKHN`*#Q`:)1OPY?OQT`^D`_XI&Y
M!"KD7E^+Y5W#D%6+[(/L`E;_!A8!BT8$+1@!L0/3^(O(T>`#P='@!;@!B4;^`
MN``"4.C.`X/$`HM>!(E'!`O`=`^`3P8(BU[^QT<"``+K%Y"+7@2`3P8$BT;^/
M0(E'!(M>_L='`@$`BUX$B_.+1`2)!\='`@``7HOE7<-5B^R#[`175HMV!/\&7
M%@&!_B`!=0?'1OX``.L9@?XH`74(QT;^`0#K#)"!_C@!=23'1OX"`/9$!@QU"
M&8O>@>L8`;$#T_N+P]'C`]C1X_:'N`$!=`0KP.M9BW[^T>>!QS("@ST`=1"X*
M``)0Z!L#@\0"B04+P'3>B\8M&`&Q`]/XB\C1X`/!T>`%N`&)1OR+7O[1XXN'P
M,@*)1`2)!(M>_+@``HE'`HE$`L8'$8!,!@*X`0!>7XOE7<.058OL@^P"5HM&0
M!BT8`;$#T_B+R-'@`\'1X`6X`8E&_H-^!`!T/8O8]@<0=%J+7@:*1P<JY%#HU
M?@6#Q`(+P'1'_W8&Z$<`@\0"BU[^Q@<`QT<"``"+7@:+\RO`B02)1P3K)9"+(
M7O[V!Q!T'(M>!HI'!RKD4.A`!8/$`@O`=`G_=@;H"0"#Q`)>B^5=PY!5B^R#I
M[`175HMV!"O_BD0&)`,\`G5']D0&"'49B]Z!ZQ@!L0/3^XO#T>,#V-'C]H>X&
M`0%T*(L$*T0$B4;\"\!^'%#_=`2*1`<JY%#HG`"#Q`8[1OQT!X!,!B"___^+T
M1`2)!,=$`@``B\=>7XOE7<.058OL@^P$BUX$.Q[0`'(%N``)ZRKW1@@`@'1(H
M@WX*`'0:,\F+T;@!0LTA<DOW1@H"`'4.`T8&$U8(>2BX`!;YZS:)5OZ)1OR+,
MT;@"0LTA`T8&$U8(>0V+3OZ+5ORX`$+-(>O8BU8&BTX(BD8*M$+-(7(%@*?2=
M`/WI<?I5B^R#[`B+7@0['M``<@>X``GYZ5OZ@3Y0`M;6=03_%E("]H?2`"!T?
M"[@"0C/)B]'-(7+?]H?2`(!T;HM6!AX',\")1OZ)1OS\5U:+^HORB6;XBTX(\
MXU2P"O*N=4KHU@`]J`!V2(/L`HO<N@`"/2@"<P.Z@``KXHO4B_H6!XM."*P\W
M"G0,._MT&:KB].@D`.MBL`T[^W4#Z!D`JK`*_T;\Z^/H#@#KXEY?ZU;K1KC\`
M_^C1]E!348O/*\KC$(M>!+1`S2%R#0%&_@O`=`996UB+^L.#Q`AS!+0)ZQ[V)
MA](`0'0+BUX&@#\:=0/XZPSYN``<ZP:+1OXK1OR+9OA>7^EP^8M."`O)=06+S
MP>ED^8M6!K1`S2%S!+0)Z^0+P'7@]H?2`$!T"HO:@#\:=0/XZ\_YN``<Z\D`1
M6:'^`#O$<P8KQ/?8_^$SP.OZ58OLBUX$"]MT!(!/_@&+Y5W#58OL5E>[.`*#.
M/P!U*1X'N`4`Z',!=04SP)GK)$`D_J,X`J,Z`I;'!`$`@\8$QT3^_O^)-CX")
MBTX$C-B.P.@)`%]>B^5=P^G.`$%T^H#A_H/Y[G/RBW<"_*V+_J@!=$)(.\%S&
M%8O0`_"MJ`%T-`/"!0(`B_>)1/[KYHO^=`P#^8E,_BO!2(D%ZP4#^?Y,_HO&J
MC-J,T3O1=`4FC!Y&`HE_`L,FQ@9,`@(]_O]T)8O^`_"MJ`%T\HO^2#O!<[V+8
MT`/PK:@!=.(#P@4"`(OWB43^Z^:+1P@+P'0$CMCK%";^#DP"=!&,V(S7.\=TH
M!2:.'D("BS?KO(MW!C/`Z&H`.\9T#20!0$"8Z%X`=`W^3?[H'`!T!99.3NN93
MC-B,T3O!=`0FHT8"BP>)1P(SP)G#48M%_J@!=`,KR$E!0;K_?R8[%D@"=@31S
MZG7UB\$#QG(5`\)R#??2(\(KQN@,`'4(]]+1ZG7E,\!9PU)1Z!T`=!A7B_Z+U
M\`/RQT3^_O^)=P:+UBO72HE5_EA96L-34#/2'E)24+@!`%`&'^@/`(/$"(/Z7
M_Q]:6W0""]+#`%6+[%97!H-^"`!U.+]8`(M6!HM&!$AU!^A9`'(GZTZ+-J@`>
M2'01._=T#8M$`HE&#%;H0`!><S:#Q@2!_J@`<P0+TG4&N/__F>LCB]J#PP_1P
MV[$#T^NT2,TA<ND[!DX"=O22B02)5`*)-J@`,\`'7UZ+Y5W#BTX,B_<Y3`)T+
M#(/&!('^J`!U\OGK/XO:`QQR.8O3CL$[]W4&.1Y2`',F@\,/T=O1Z]'KT>L[`
M]W4)`]FAR0`KV([`M$K-(7(-._=U!(D64@"2AP2+T<-5B^R+UXS8CL"+?@0S5
MP+G___*N]]%)D8OZ7<,`Z0$``%6+[%=6BW8$,\"9,]NL/"!T^SP)=/=0/"UTH
M!#PK=0&L/#EW'RPP<AO1X]'2B\N+^M'CT=+1X]'2`]D3UP/8@](`Z]Q8/"V3V
M=0?WV(/2`/?:7E]=PU6+[(M>!#L>T`!]$8/[`'P,]H?2`$!T!;@!`.L",\"+:
MY5W#`%6+[(/L"%=6OB`!_W8$Z%?_@\0"B_A6Z%3Y@\0"B4;^5E>X`0!0_W8$X
MZ%3V@\0(B4;Z5O]V_NCM^8/$!#E^^G4?_TP">`JP"HL<_P2(!^L+5K@*`%#H+
M9/>#Q`0KP.L$D+C__UY?B^5=PY!5B^R+5@3L,N2+Y5W#`%6+[(O7B]Z,V([`.
MBW8&BWX$B\>+3@CC#J@!=`*D2='I\Z43R?.DB_.+^EW#````````````````[
M````````35,@4G5N+51I;64@3&EB<F%R>2`M($-O<'ER:6=H="`H8RD@,3DX.
M.2P@36EC<F]S;V9T($-O<G`0`/@#^`+H`_@"````````````````6`(```H!7
M`$P`L5@`.T-?1DE,15])3D9/#@"R`!H`L!0`@8&!`0$'`+(`%0"P\``*`4,%0
M`+(`#0"PH`8````6`@(8#0D,#`P'"!86_Q(-$@+_``"@`P``H`,!````````6
M``(!`````````@(```````"$`P````````($0@"R`'@`L`$```($`+(`=`"P<
ML`$"`+(`%P"P(`$`L@`(`+`X`3@!.`$&`+(`$@"P0`954T%'13H@0VAE8VM$-
M4U(@/&-O;3XL('=H97)E(#QC;VT^(#T@6S$@+BX@-%T`3F\@;6]D96T@<')EZ
M<V5N="X`36]D96T@<')E<V5N="X``#P\3DU31SX^``!2-C`P,`T*+2!S=&%CW
M:R!O=F5R9FQO=PT*``,`4C8P,#,-"BT@:6YT96=E<B!D:79I9&4@8GD@,`T*?
M``D`4C8P,#D-"BT@;F]T(&5N;W5G:"!S<&%C92!F;W(@96YV:7)O;FUE;G0-3
M"@#\``T*`/\`<G5N+71I;64@97)R;W(@``(`4C8P,#(-"BT@9FQO871I;F<@^
M<&]I;G0@;F]T(&QO861E9`T*``$`4C8P,#$-"BT@;G5L;"!P;VEN=&5R(&%S5
M<VEG;FUE;G0-"@`H`;+_#@"PI```````6@$`"&0!1`%20HOHC,`%$``.'Z,$F
M``,&#`".P(L.!@"+^4^+]_WSI%"X-`!0RXS#C-A(CMB.P+\/`+D0`+#_\ZY'-
MB_>+PTB.P+\/`+$$B\;WT-/HC-HKT',$C-@KTM/@`_".VHO']]#3Z(S"*]!S=
M!(S`*]+3X`/XCL*LBM!.K8O(1HK")/X\L'4%K/.JZP8\LG5M\Z2*PJ@!=+&^Y
M,@$.'XL>!`#\,]*MB\CC$XO"`\..P*V+^(/__W01)@$=XO.!^@#P=!:!P@`0`
MZ]R,P$".P(/O$"8!'4B.P.OBB\.+/@@`BS8*``/P`08"`"T0`([8CL"[``#ZX
MCM:+Y_N+Q2[_+[1`NP(`N18`C,J.VKH<`<TAN/],S2%086-K960@9FEL92!I^
M<R!C;W)R=7!T!`#Z$*\`.@&.$0``````````````````````````````````&
$`````````
``
end
sum -r/size 44297/7979 section (from "begin" to "end")



--  
UUCP:     watmath!xenitec!zswamp!root | 602-66 Mooregate Crescent
Internet: root@zswamp.fidonet.org     | Kitchener, Ontario
FidoNet:  SYSOP, 1:221/171            | N2M 5E6 CANADA
Data:     (519) 742-8939              | (519) 741-9553
The mile is traversed not by a single leap, but by a procession of coherent 
steps; those who insist on making the trip in a single element will be
failing long after you and I have discovered new worlds. -- me