WTB: USB DC Coders Cable

Anyone have one of these they built and want to part with? Or want to build one for some cash? The old one would work as well I just have to get a new PC that support LPT ports is all so yea the USB is faster and preferred. I am trying to get compile a database of all the prefetch files as i am making a compatibiltiy list for NEO4all.


http://www.axlen.com/usbcc.html

In case you are just curious!

 

Pretty sure its serial you want, not parallel.

Parallel ports can be quite hard to get on new machines, but serial isnt so bad.
Also, you can just use a USB-> Serial adapter as thats all the coders cable is that you linked to....

a FTDI based usb-> serial cable + original coders cable will be the same as what you make from that site.

Unless you do not have an original cable, then I guess it makes sense to just go with a USB one.

 

Coders cable has a MAX232 crammed in there and limits the Dreamcast to something like 7-8kb/s. A USB cable has considerably more speed IIRC.

If that wasn't the case then the SD card mod would be slow and worthless.

 

115200 is around 15 KB/s

I dont think a max232 is limited to just that tho as its just a level shifter, the issue is the driver for the USB -> Serial not supporting weird speed settings - which hacked up FTDI drivers (for the usb-> serial part) should cover.

If you use a serial cable directly into a machine, you are limited by the drivers for the com port to use "normal" speeds (i.e. standard baud settings).

Its possible the max232 has some upper limit, but I don't think its the limiting factor in this case.

 

Personally I've never seen the MAX232 be used at more than 115200 so I always assumed they didn't build it more capable than that speed. Obviously my reasoning was flawed.

But I'd swear I've seen someone who actually had one of these that it got a full 1.2mb/s or so. Megabits that is. The SD card does some pretty good speeds so I know it's at least possible.

 

I just dont think weird baud rates are all that common. This is very much a case of making something designed for 1 thing work for another.

Thats probably why using a max232 at crazy speeds hasnt been seen before - because theres nothing that uses it.

Not saying that it will work 100%, but I don't really see a reason why it shouldn't.... the schematic above is just using a FTDI chip (which would be in the USB -> Serial adapter) and the max232 is just there for shifting levels between RS232 and TTL... which technically isnt really needed as the USB serial adapter wont be using -12v or what ever RS232 uses.

Maybe the MAX232 wont work that fast.... but as its not really a documented use/baud its probably not going to show up on googling - a case of just try it.

If hes already got a coders cable, its worth trying. USB -> serial adapters are always handy anyway and FTDI ones are one of the best.


edit:

also, I wasn't saying this cable will only do 15KB. I was saying a standard baud rate of 115200 (which would be possible on a normal comport, with a normal cable) it 15KB - not 7-8KB you mentioned.

 

Don't care how fast it would be I just need to grab all the prefetch files for a data base and a USB coders cable would be best suited for me.