Page Location: Home > VS Link Games > Topic
1, 2  Next
lordnikon
rank 86
Posted:
Sun Nov 24, 2013 7:42 pm
quote : #1
profile : pm
Posts: 5829
Type: NTSC-U/C
Does anyone have any hardware uses for a non-working Dragoncast cable? Can these be repaired? or repurposed for something else?
  _________________
Sega AM2 presents Waves of Grain - "Powerslide your way through the fields to deliver the wheat crop!"
Dreamcast ™
rank 39
Posted:
Sun Nov 24, 2013 11:39 pm
quote : #2
profile : pm
Posts: 908
Type: NTSC-U/C
You can use the ends to make two serial programmer's cables. They're also easy to repurpose to new VS cables since there's no first-party proprietary circuitry. Repairing them is difficult because, if I remember correctly, there is an internal glue chip.
 
lordnikon
rank 86
Posted:
Wed Nov 27, 2013 11:04 pm
quote : #3
profile : pm
Posts: 5829
Type: NTSC-U/C
Man I must be slippin'. I totally forgot that I could fashion them into Coders Cables. I guess when you have 3 BBA's you sort of forget about the coders cable.
  _________________
Sega AM2 presents Waves of Grain - "Powerslide your way through the fields to deliver the wheat crop!"
Dreamcast ™
rank 39
Posted:
Thu Nov 28, 2013 1:54 am
quote : #4
profile : pm
Posts: 908
Type: NTSC-U/C
Haha, I agree. The main reason to have a coder's cable with BBAs is if you're doing network development. Unless I've been implementing it wrong, running code that uses its own network stack interrupts the stack set up for dc-load-ip software, so the only way around that is to upload the binary through the coder's cable.
 
lordnikon
rank 86
Posted:
Thu Nov 28, 2013 10:46 am
quote : #5
profile : pm
Posts: 5829
Type: NTSC-U/C
Hmm I never thought of that. Interesting. Is it hard to make a coder's cable? What is the difficulty rating on that?
  _________________
Sega AM2 presents Waves of Grain - "Powerslide your way through the fields to deliver the wheat crop!"
Dreamcast ™
rank 39
Posted:
Thu Nov 28, 2013 10:54 am
quote : #6
profile : pm
Posts: 908
Type: NTSC-U/C
Here is a schematic for building one (link). It's just a MAX3222 level converter and a few capacitors. The great thing about building two coder's cables out of a VS link cable is that you have two coder's cables PLUS, using a null modem adapter, you can connect the two cables together and have a VS cable again.
 
iluk
rank 3
Posted:
Sat Apr 04, 2015 2:48 pm
quote : #7
profile : pm
Posts: 17
Type: NTSC-J
I own two different coder's cables. Are you sure that using a null modem between those is safe ? Did someone ever try it ?
If I build the null modem cable, could I do this way please :
http://www.lammertbies.nl/comm/info/RS-232_null_modem.html#noha
 
Dreamcast ™
rank 39
Posted:
Sat Apr 04, 2015 2:53 pm
quote : #8
profile : pm
Posts: 908
Type: NTSC-U/C
It's 100% safe as long as the signal voltages are the same on each end of the coder's cable. I've also connected a Dreamcast with a coder's cable to a Dreamcast Dev.Box's serial port to make a VS connection and it works fine.
 
iluk
rank 3
Posted:
Sat Apr 04, 2015 3:03 pm
quote : #9
profile : pm
Posts: 17
Type: NTSC-J
Ok thanks ! Should I check the voltages of each cable before ? I will try but not sure there is continuous voltage on the pins. Do you think building the null modem only requires 3 pins as shown on the website, say Rx to Tx, Tx to Rx, and ground ?
 
iluk
rank 3
Posted:
Sat Apr 04, 2015 5:42 pm
quote : #10
profile : pm
Posts: 17
Type: NTSC-J
I had a look to the voltages to compare the two cables. I did the measure with the same dreamcast, at the end of coder cable, on same rs232 pins (between Rx and ground). With one cable there is 5.8V and with the other there is 9.7V.
I guess these ranges are compatibles but I am not sure.

Here are the datasheets of each coder cable IC, maybe someone could help to confirm those are compatibles ?

ICL232CPE
http://www.intersil.com/content/dam/Intersil/documents/icl2/icl232.pdf

MAX3232CPE
http://datasheets.maximintegrated.com/en/ds/MAX3222-MAX3241.pdf

Thanks.
 
Dreamcast ™
rank 39
Posted:
Sat Apr 04, 2015 7:12 pm
quote : #11
profile : pm
Posts: 908
Type: NTSC-U/C
It should be OK since RS-232 has an operating range of ~ 3 - 15V. The most important thing is the level conversion they each provide. The Dreamcast's I/O port operates at CMOS 3V levels whereas the RS-232 levels are 5.0V.
 
iluk
rank 3
Posted:
Sun Apr 05, 2015 12:55 pm
quote : #12
profile : pm
Posts: 17
Type: NTSC-J
Ok, it worth the try Smile By the way, the dreamcast seems to detect the link cable, because I have a dragoncast cable and even if I switch on one dreamcast only, the cable versus option is selectable on F355. But with a coder cable only, it's not selectable (shown in grey).
Also, would you be able to give the null modem model that you use please ? Or maybe look the wiring ? It would help me so much.
Even if I have the dragoncast, I want to know more about the vs link, and I expect to use a sniffer on the line to see what happens !
 
lordnikon
rank 86
Posted:
Sun Apr 05, 2015 5:20 pm
quote : #13
profile : pm
Posts: 5829
Type: NTSC-U/C
iluk wrote:
Ok, it worth the try Smile By the way, the dreamcast seems to detect the link cable, because I have a dragoncast cable and even if I switch on one dreamcast only, the cable versus option is selectable on F355....

Hmm interesting. I will have to try that again. Maybe it means my Dragoncast can be repaired.
  _________________
Sega AM2 presents Waves of Grain - "Powerslide your way through the fields to deliver the wheat crop!"
Dreamcast ™
rank 39
Posted:
Sun Apr 05, 2015 6:36 pm
quote : #14
profile : pm
Posts: 908
Type: NTSC-U/C
I use a generic null-modem adapter I purchased from the now somewhat defunct RadioShack a while ago. The Wikipedia page for null modem adapters has a wiring diagram for a DB-9 adapter.

The important parts to note are that the CD (carrier detect) lines are tied to the DSR (data set ready) lines on each end. Naturally, RX (receive) and TX (transmit) are crossed along with DTR (data terminal ready) / DSR (data set ready) and RTS (request to send) and CTS (clear to send).

I placed an order for some parts to build two new identical coder's cables to test the connection, so hopefully I will be able to answer your first question by the end of this week. Currently I only have one coder's cable and one Dragoncast cable.
 
iluk
rank 3
Posted:
Mon Apr 06, 2015 3:13 am
quote : #15
profile : pm
Posts: 17
Type: NTSC-J
Thank you for all these details !
Very nice of you to build coder's cables Smile

I made a website to share dreamcast infos (french), here are my 2 cables :
http://topdream.imaginux.com/topliste.php?fiche=10
http://topdream.imaginux.com/topliste.php?fiche=23

So I will also try the null modem as you describe it.
By the way, will you cut your dragoncast to build your coder cables ?!
 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
Display:   
 
View previous topic - View next topic
Page Location: Home > VS Link Games > Topic
1, 2  Next