[busted bit]

I'm sure this has been asked many times yet I cant seem to find what I'm looking for via the search function. I have an old VF-2 with RS-232 only. I want to use a USB on my laptop to get the program over to the machine. I have seen some purpose built adapter "boxes" that were a little pricey and at one point a while back I tried a cheap Belkin USB to 232 adapter which did send a partial program before throwing an alarm. After messing with the settings I concluded it was inadequate in some way. Is there anything out there proven to work in this application that is inexpensive? thanks

[Little_Chips]

Check this out RS232 serial null modem cable wiring and tutorial and look at the diagram in "Null modem with loop back handshaking" section. You may need the jumpers at each end of the cable.

You may want to try this adapter cable https://www.sparkfun.com/products/11304 as it has a RS-232 driver chip. Sometimes the adapters only use 5V logic and it is a little less coming out of the computer which will be just under the threshold where it can work reliably. Sometimes the driver for the adapter is crummy. I have had the same problem. I believe this is a good one 232USB9M from B&B Electronics Mini USB to Serial Converter | Mini USB to RS232 - B&B Electronics although I would probably try the inexpensive one from Sparkfun first.

[busted bit]

Thanks LC. Very informative article too. Know I know how it all works. I will give the Sparkfun unit a try

[newman55598]

I went thru 3 of them before finding one that worked consistently. The ones that use the ftdi chipset seem to be more reliable in my experience.

[dharmic]

Not to mention that half the "Prolific" based ones are knock-offs for which the drivers for Window 7 onwards are programmed to not work.