[ISMAP]-Deja News Toolbar Interest Finder Browse Groups New On Our Site! Search ______________________________ Find Find messages in the [complete] archive (_) Search By Product (_) Search By Manufacturer ____________ [IMAGE]-Submit Message 17 of 23 return to comp.sys.cbm [USEMAP] previous · post reply · next help The 35 cent modem [LONG] more options Author: John Iannetta Email: 73510.2152@CompuServe.COM Date: 1998/10/27 Forums: comp.sys.cbm more headers author profile view thread _________________________________________________________________ To transfer files from a C-64/1541 to a PC, many users use the X1541 cable. But many newer PC printer cards use driver circuits that cannot be used with that cable. The XE1541 (described in the docs for Joe Forster's "Star Commander") will probably work, but it requires four Schottky diodes. Two other methods come to mind. One is a modem-to-modem connection; the other is using a null modem adapter and a connection to the PC's serial port. On the C-64 end, the first requires either a direct-connect ("Commodore-ready") modem or an RS-232 interface adapter connected to the user port, along with an external RS-232 modem. In place of the adapter, a true RS-232 cartridge may be used (e.g., SwiftLink or Turbo232) connected to the expansion (cartridge) port. The second method requires either the adapter or cartridge, but uses the null modem adapter (typical cost of about five dollars US) in place of the modem. Each of the two methods requires a terminal program on each end (called "Communications Software" in the MS-DOS world). This article offers another option, which requires soldering only two wires, and probably no more than a 35-cent financial investment. SID (either a 6581 or an 8580 IC) is used as an FSK (Frequency-Shift Keying) generator at 300 baud, in accordance with the Bell 103 standard. Only simplex operation is supported, so the direction is only from C-64 to other computer. Also, since the Xmodem routine is "open-loop" (the C-64 ignores ACK's and NAK's that it reFA: 12 NEW C64 Games & 4 Loose Cartridge s $0.01 (1 article)ceives), delays are used between blocks. Xmodem-CRC is used, since most terminal programs initiate downloads expecting that form of Xmodem. The hardware consists of a length of telephone cable with a modular plug on one end and an RCA phono jack on the other. One idea is to take a cable that is used for connecting between a modem and a wall jack, and cut off one of the connectors. Strip the insulation from the red and green wires, and solder them to an RCA phono jack (listed in my Jameco catalog at 35 cents each). In operation, the RCA phono plug is removed from the audio input jack of the monitor, and the plug is connected to the aforementioned jack. The modular plug, of course, connects to the modem of the other computer. The software for the C-64 is the type-in BASIC program listed below. The other computer should be running general purpose communications software; I tested the method using PROCOMM on a '386/25 MS-DOS computer. I transferred a 128 Kbyte file without problems. To transfer a file, load and run the BASIC program, and wait for the blank screen. Then, with the other computer's program running (and set to 300 baud), type in: ATX1D on the other computer. After a few seconds, you should see "CONNECT" on its screen. You should also see whatever you type in on the C-64's keyboard (using unshifted keys). To exit, press F7; to send a file, press F1. You will then be prompted for a device number (4 to 30) and a filename. Right before you press , initiate an Xmodem download on the other computer. You will not see anything displayed on the C-64 screen. But if all goes well, you will see the transfer proceed on the other screen. If there is even one error, you might as well abort; the transfer cannot recover. I used a ZOOM 2400 fax/modem; high-speed modems may not support 300 bps. NTSC version ------------ 10 poke55,.:poke56,160:clr:c=49152:b=1 20 ready$:print"reading line";b;"of 20" 30 fork=1to2:a$=mid$(y$,j*2+k) 40 a=asc(a$)-48:ifa>9thena=a-7 50 e=a+16*e:next:ife=256then90 60 pokej+i+c,e:n=n+e:j=j+1:e=0 70 ifj=15thenj=0:i=i+15:b=b+1:goto20 80 goto30 90 s=54272:ifn=38107then110 100 print"data statement error":end 110 d=56320:fori=stos+24:pokei,.:next 120 e=56576:pokee+4,80:z=d+13:pokez,127 130 pokee+5,13:pokee+13,127:pokee+15,8 140 pokes+6,240:pokes,148:pokes+1,142 150 pokes+24,6:pokee+11,.:pokee+14,1 160 poked+15,8:poked+11,.:pokes+4,17 170 sys49152:pokez,129:ifpeek(2)then190 180 end 190 pokez,129:printchr$(147);chr$(14) 200 n=.:print"Enter device number." 210 print:print" 8";chr$(145):inputn 220 ifn=.thenend 230 ifn<4orn>30thenprint:goto200 240 print:print"Enter filename." 250 f$="":print:inputf$:iff$=""thenend 260 open9,3,9,f$:poke184,8 270 poke185,8:poke186,n:sys65472 280 ifst=.thenclose9:goto310 290 print:print"DEVICE NOT PRESENT" 300 close9:close8:print:goto200 310 open15,n,15:input#15,j$,o$,h$,n$ 320 ifj$="00"then350 330 print:printj$,o$:printh$,n$ 340 close15:close8:print:goto200 350 sys49276:close15:close8 500 data 2018e5ad0ddcf0fb2087eaa5c6f0f4 510 data 2042f1c985f00ec988f0082016e720 520 data 27c090e1a90085026085b086b184b2 530 data ae0dddae0dddf0fba2818e01d4a2c3 540 data 8e00d4a008ae0dddf0fb4ab00fa281 550 data 8e01d4a2c38e00d488d0ebf00da28e 560 data 8e01d4a2948e00d488d0dcae0dddf0 570 data fba28e8e01d4a2948e00d4a5b0a6b1 580 data a4b21860a97f8d0ddca20820c6ffa9 590 data 018596a9008502a9012027c0a59620 600 data 27c049ff2027c0a00320a5ff858b20 610 data 27c0e602a690f006a91a858cd06220 620 data a5ff858c2027c0a690d056e60220a5 630 data ff2027c0858da208068d268c268b90 640 data 0ca58b4910858ba58c4921858ccad0 650 data e9a590d02fe60210d78a88d0d9e696 660 data a58b2027c0a58c2027c0e88a4868aa 670 data d0f9c8d0f6a590f082a9042027c0a9 680 data 818d0ddc4cccffe60230d1a91ad0a7 690 data 00g0 PAL version ----------- 10 poke55,.:poke56,160:clr:c=49152:b=1 20 ready$:print"reading line";b;"of 20" 30 fork=1to2:a$=mid$(y$,j*2+k) 40 a=asc(a$)-48:ifa>9thena=a-7 50 e=a+16*e:next:ife=256then90 60 pokej+i+c,e:n=n+e:j=j+1:e=0 70 ifj=15thenj=0:i=i+15:b=b+1:goto20 80 goto30 90 s=54272:ifn=37801then110 100 print"data statement error":end 110 d=56320:fori=stos+24:pokei,.:next 120 e=56576:pokee+5,12:z=d+13:pokez,127 130 pokee+4,211:pokee+13,127:pokee+15,8 140 pokes+6,240:pokes,.:pokes+1,148 150 pokes+24,6:pokee+11,.:pokee+14,1 160 poked+15,8:poked+11,.:pokes+4,17 170 sys49152:pokez,129:ifpeek(2)then190 180 end 190 pokez,129:printchr$(147);chr$(14) 200 n=.:print"Enter device number." 210 print:print" 8";chr$(145):inputn 220 ifn=.thenend 230 ifn<4orn>30thenprint:goto200 240 print:print"Enter filename." 250 f$="":print:inputf$:iff$=""thenend 260 open9,3,9,f$:poke184,8 270 poke185,8:poke186,n:sys65472 280 ifst=.thenclose9:goto310 290 print:print"DEVICE NOT PRESENT" 300 close9:close8:print:goto200 310 open15,n,15:input#15,j$,o$,h$,n$ 320 ifj$="00"then350 330 print:printj$,o$:printh$,n$ 340 close15:close8:print:goto200 350 sys49276:close15:close8 500 data 2018e5ad0ddcf0fb2087eaa5c6f0f4 510 data 2042f1c985f00ec988f0082016e720 520 data 27c090e1a90085026085b086b184b2 530 data ae0dddae0dddf0fba2868e01d4a2b3 540 data 8e00d4a008ae0dddf0fb4ab00fa286 550 data 8e01d4a2b38e00d488d0ebf00da294 560 data 8e01d4a2008e00d488d0dcae0dddf0 570 data fba2948e01d4a2008e00d4a5b0a6b1 580 data a4b21860a97f8d0ddca20820c6ffa9 590 data 018596a9008502a9012027c0a59620 600 data 27c049ff2027c0a00320a5ff858b20 610 data 27c0e602a690f006a91a858cd06220 620 data a5ff858c2027c0a690d056e60220a5 630 data ff2027c0858da208068d268c268b90 640 data 0ca58b4910858ba58c4921858ccad0 650 data e9a590d02fe60210d78a88d0d9e696 660 data a58b2027c0a58c2027c0e88a4868aa 670 data d0f9c8d0f6a590f082a9042027c0a9 680 data 818d0ddc4cccffe60230d1a91ad0a7 690 data 00g0 -- John _________________________________________________________________ Email a Friend Sponsored by: Audio Book Club [USEMAP] previous · post reply · next help (_) Search By Product (_) Search By Manufacturer ____________ [IMAGE]-Submit Home · Search · My Deja News · Post · Power Search · Help · How are we doing? 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