I have a couple of VCRs with JVC's JLIP interface. I understand JLIP is a form of RS232 although it uses a 3.5mm mini jack.

Does anyone have (or know where I could get) a list of the RS232 commands to control VCRs with JLIP?

If it is a 3.5 mm stereo plug/jack then it is probably a three wire serial system The question is which parts of the plug (Sleeve, ring, tip) are ground, receive, transmit?

I found information about the wiring here - about 2/3 of the way down:

[Link: pixcontroller.com]

It looks like tip is receive, ring is transmit, and sleeve is ground.

But that's not much use without knowing the commands.

Maybe a bit late reply, but for anyone else playing with JLIP.
I have a JVC HR-9600 S-VHS video with a JLIP contact on the back. I have done some research on this. I found a protocol document and JLIP debugger tool(useful of testing cable and calculate checksum) and information about the cable. You need a special cable because JLIP and RS232 don't use same voltage levels. There is a JVC PC cable (sparepart number QAM0099-02), a Marantz cable;AJ8300 RS-232 cable or you can build the cable yourself with some electronic skills. Also note that the electronics in the cable need 5V so if conected to a philips extender (RFX9600) you have to modify cable and connect it to +5V. You can test the cable first connected to a PC with the mentioned JLIP debug tool (in that case the +5V comes from the PC).

More information about JLIP protocol, this is for a Marantz MV8300 (think it's a rebranded JVC D-VHS vcr):
[Link: d-mpro.com]

More information about cable and JLIPD (JLIP debugger) download:
[Link: garfield.planetaclix.pt]

I have tested theese commands on my JVC HR-9600;
Power OnFF FF 01 3E 40 70 00 00 00 00 13
Power OffFF FF 01 3E 40 60 00 00 00 00 23
CH up FF FF 01 0A 44 73 00 00 00 00 40
CH down FF FF 01 0A 44 63 00 00 00 00 50
PlayFF FF 01 08 43 75 00 00 00 00 41
StopFF FF 01 08 44 60 00 00 00 00 55
PauseFF FF 01 08 43 6D 00 00 00 00 49
FFFF FF 01 08 44 75 00 00 00 00 40
RewFF FF 01 08 44 65 00 00 00 00 50
Eject FF FF 01 08 41 60 00 00 00 00 58
Fast Play fwdFF FF 01 08 43 21 00 00 00 00 15
Fast Play bwdFF FF 01 08 43 21 00 00 00 00 15
Slow Play fwdFF FF 01 08 43 20 00 00 00 00 16
Slow play bwdFF FF 01 08 43 24 00 00 00 00 12
RecFF FF 01 08 42 70 00 00 00 00 47
Rec PauseFF FF 01 08 42 6D 00 00 00 00 4A

Input selectFF FF 01 08 43 21 00 00 00 00 15
Counter resetFF FF 01 48 4D 20 00 00 00 00 4C

Tuner mode req FF FF 01 0A 4E 20 00 00 00 00 09

ch directset01FF FF 01 0A 44 71 00 01 7E 00 43
ch directset02FF FF 01 0A 44 71 00 02 7E 00 42
ch directset03 FF FF 01 0A 44 71 00 03 7E 00 41
ch directset04 FF FF 01 0A 44 71 00 04 7E 00 40
ch directset05FF FF 01 0A 44 71 00 05 7E 00 3F
ch directset06FF FF 01 0A 44 71 00 06 7E 00 3E
ch directset07 FF FF 01 0A 44 71 00 07 7E 00 3D
ch directset08 FF FF 01 0A 44 71 00 08 7E 00 3C
ch directset09FF FF 01 0A 44 71 00 09 7E 00 3B