Post #287,913
6/27/07 10:04:19 AM
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Modem to modem w/out Ma Bell?
I recently acquired a C= 128 again and wanted to transfer my game [link|http://home.houston.rr.com/spiceware/c128.html|Alien Invaders] over to it.
Back in the day of 300 baud I did a presentation on BBSes at the Commodore user group in Corpus Christi. I recall connecting two 64s together directly via modems as part of the demo. Tried that with the 128 and my iMac but they won't talk to each other. I made sure both were set to 1200 8N1, used ATA on one, ATO on the other. Then tried the ATs the other way around.
It's been a long time since I've used a modem - am I not remembering the AT commands correctly?
Darrell Spice, Jr. Trendy yet complex\nPeople seek me out - though they're not sure why\n[link|http://spiceware.org/gallery/ArtisticOverpass|Artistic Overpass] [link|http://www.spiceware.org/|SpiceWare]
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Post #287,915
6/27/07 10:10:01 AM
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cable needs to be inverted?
pin2 on mac connects to pin 3 on 128 and vice versa
nice diagram
[link|http://www.beyondlogic.org/serial/serial.htm#2|http://www.beyondlog...rial/serial.htm#2]
thanx,
bill
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
Any opinions expressed by me are mine alone, posted from my home computer, on my own time as a free american and do not reflect the opinions of any person or company that I have had professional relations with in the past 51 years. meep
reach me at [link|mailto:bill.oxley@cox.net|mailto:bill.oxley@cox.net]
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Post #287,919
6/27/07 10:25:02 AM
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not serial to serial
modem to modem.
The Commodore modem plugs into the [link|http://www.gamesx.com/hwb/co_UserIOC64.html|user port], which is similar to, but different than, an RS-232 port. I believe voltage differences are the biggest factor, the user port is TTL(0-5 volts) while serial is something like -12 to +12.
Darrell Spice, Jr. Trendy yet complex\nPeople seek me out - though they're not sure why\n[link|http://spiceware.org/gallery/ArtisticOverpass|Artistic Overpass] [link|http://www.spiceware.org/|SpiceWare]
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Post #287,927
6/27/07 12:57:27 PM
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modems are 2 wire serial devices
if the transmit pin on the 128 is hitting the transmity pin on the mac it wont work
thanx,
bill
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
Any opinions expressed by me are mine alone, posted from my home computer, on my own time as a free american and do not reflect the opinions of any person or company that I have had professional relations with in the past 51 years. meep
reach me at [link|mailto:bill.oxley@cox.net|mailto:bill.oxley@cox.net]
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Post #287,936
6/27/07 1:59:25 PM
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Gotcha, will check for that.
Darrell Spice, Jr. Trendy yet complex\nPeople seek me out - though they're not sure why\n[link|http://spiceware.org/gallery/ArtisticOverpass|Artistic Overpass] [link|http://www.spiceware.org/|SpiceWare]
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Post #287,917
6/27/07 10:15:50 AM
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AT command set
[link|http://www.modemhelp.net/basicatcommand.shtml|http://www.modemhelp...icatcommand.shtml]
[link|http://docs.kde.org/stable/en/kdenetwork/kppp/appendix-hayes-commands.html|http://docs.kde.org/...yes-commands.html]
-YendorMike
"They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety."
- Benjamin Franklin, 1759 Historical Review of Pennsylvania
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Post #287,920
6/27/07 10:27:27 AM
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Hmm - possibly ATO1
The Hayes reference I found last night didn't mention the 1 option for retraining.
Thanks!
Darrell Spice, Jr. Trendy yet complex\nPeople seek me out - though they're not sure why\n[link|http://spiceware.org/gallery/ArtisticOverpass|Artistic Overpass] [link|http://www.spiceware.org/|SpiceWare]
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Post #288,009
6/28/07 9:44:22 AM
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No luck :-(
Darrell Spice, Jr. Trendy yet complex\nPeople seek me out - though they're not sure why\n[link|http://spiceware.org/gallery/ArtisticOverpass|Artistic Overpass] [link|http://www.spiceware.org/|SpiceWare]
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Post #287,933
6/27/07 1:36:00 PM
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From ancient experience... (a bit rusty)
On leased lines (direct connect without dial-tone) the phone company has always had to provide pull-up current.
Which means unless you force both the MAC and C128 modem to start negotiations, it'll never work.
I'll be betting it'll be better to have the MAC answer the "call" or be the upstream. Start the C128 and then have the mac answer. Negs will probably fail. You may have to force specific modes on both.
Plus, the problem might be the MACs modem might not support the low baud rates properly.
--
[link|mailto:greg@gregfolkert.net|greg],
[link|http://www.iwethey.org/ed_curry|REMEMBER ED CURRY!] @ iwethey
PGP key: 1024D/B524687C 2003-08-05
Fingerprint: E1D3 E3D7 5850 957E FED0 2B3A ED66 6971 B524 687C
Alternate Fingerprint: 09F9 1102 9D74 E35B D841 56C5 6356 88C0
Alternate Fingerprint: 455F E104 22CA 29C4 933F 9505 2B79 2AB2
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Post #287,935
6/27/07 1:57:31 PM
6/27/07 2:33:12 PM
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Found something about that
[link|http://www.jagshouse.com/modem.html|Connecting two computers using their modems, without a telephone line] One necessity for a reliable connection of this type is a "line simulator", a device to provide simulation of a telephone line, supplying the line current that modems are designed to work with. For our purposes, a very simple home-made circuit will do the job (you should be able to find most, if not all, of the parts at a Radio Shack store). This connects between two telephone modular jacks, and the two modems plug into the jacks: I don't think the parts are at Rat Shack anymore. If the ATO1 doesn't work I'll investigate this info further. Hadn't thought about lower baud rate being an issue. I did notice that only the 128 was making modem sync noises. Maybe the Mac's modem needs the "line simulator" but the 128's doesn't. I've found reference to SwiftLink and Turbo232, which add a real RS232 via the cartridge port. That would work well with a null modem cable(I already have a USB serial adapter on the Mac for my [link|http://www.arminvogl.de/KrokodileCartridge/|Krokodile Cart]), plus they go faster than the 128's 1200 baud modem does. What I'd really like to do is ethernet on the 128, but haven't had any luck in finding the parts they used to make the [link|http://www.dunkels.com/adam/tfe/|The Final Ethernet - C64 Ethernet Cartridge]. I thought I'd found a possible replacement for the Embedded Ethernet board they used, but the [link|http://microcontrollershop.com/product_info.php?cPath=98&products_id=1202|CS8900A Ethernet Controller Header Board] is based on the new low-power 3 volt version of the CS8900A :-/ Darrell Spice, Jr. Trendy yet complex\nPeople seek me out - though they're not sure why\n[link|http://spiceware.org/gallery/ArtisticOverpass|Artistic Overpass] [link|http://www.spiceware.org/|SpiceWare]
Edited by SpiceWare
June 27, 2007, 02:33:12 PM EDT
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Post #287,943
6/27/07 2:37:04 PM
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Zooks!
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Post #287,970
6/27/07 5:48:08 PM
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Cirrus still makes the cs8900a
And the 74LS139 is pretty widely available.
The only thing you'd have to do was etch a double sided board. It really isn't that tough.
Some Radio Snacks still have double sided blank board and etching kits in store.
If you want I can go look round for one.
--
[link|mailto:greg@gregfolkert.net|greg],
[link|http://www.iwethey.org/ed_curry|REMEMBER ED CURRY!] @ iwethey
PGP key: 1024D/B524687C 2003-08-05
Fingerprint: E1D3 E3D7 5850 957E FED0 2B3A ED66 6971 B524 687C
Alternate Fingerprint: 09F9 1102 9D74 E35B D841 56C5 6356 88C0
Alternate Fingerprint: 455F E104 22CA 29C4 933F 9505 2B79 2AB2
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Post #287,971
6/27/07 7:12:22 PM
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If you want a double sided board, best way
if your time is worth anything is to use a proto board shop. Sierra Proto Express will do 3 double sided for $96; if you only want one, Spark Fun will do them for something like $2.50 a square inch.
--Tony
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Post #288,008
6/28/07 9:43:54 AM
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Re: Cirrus still makes the cs8900a
yeah, but the Embedded Ethernet Board is more than just the cs8900a. It makes it so you only have to wire in the address, data and read/write lines.
I see a [link|http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=018&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=280127545799&rd=1&rd=1|Swiftlink] up on ebay. If I don't win that, I found a place with the [link|http://store.cmdrkey.com/agora.cgi?cart_id=3013002.25967*4u06v4&p_id=00301&xm=on&ppinc=search3|Turbo232].
Darrell Spice, Jr. Trendy yet complex\nPeople seek me out - though they're not sure why\n[link|http://spiceware.org/gallery/ArtisticOverpass|Artistic Overpass] [link|http://www.spiceware.org/|SpiceWare]
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Post #287,937
6/27/07 2:00:06 PM
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I seem to recall from back in the dark ages . . .
. . modems over dedicated lines were very different from dial-up modems and not interchangeable one to the other (except a few models that could handle either through separate connections) - and yes, the telco dedicated line did provide voltages.
I also recall "CO emulators" were sold so demos at shows could talk to each other. CO emulators provided telephone line voltage, dial tone and ring voltage so dial-up modems could talk to each other.
Now this is very hazy, but I think there were modems designed to talk directly to other modems, mainly for in-plant industrial communications.
[link|http://www.aaxnet.com|AAx]
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Post #287,939
6/27/07 2:10:51 PM
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I still have a Courier Modem from the day...
Being a Courier HST Dual Standard modem, back when 9600 Baud had *JUST* showed up being available for any communications, leased or not.
I'll bring it to the Party.
--
[link|mailto:greg@gregfolkert.net|greg],
[link|http://www.iwethey.org/ed_curry|REMEMBER ED CURRY!] @ iwethey
PGP key: 1024D/B524687C 2003-08-05
Fingerprint: E1D3 E3D7 5850 957E FED0 2B3A ED66 6971 B524 687C
Alternate Fingerprint: 09F9 1102 9D74 E35B D841 56C5 6356 88C0
Alternate Fingerprint: 455F E104 22CA 29C4 933F 9505 2B79 2AB2
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