Cable for HP48G/G+

[Claudio L.]

(01-16-2019 02:21 PM)zx_spectrum Wrote:  I want to buy a cable to connect my HP48G and HP48G+ to PC.
this is the first time i attempt to do this. I know that there are special cables for this with DB9 connection, but i don't really know what else i would need and whether there are different variations to these cables on eBay.
I need a brand new one
I have seen three different listings on eBay that offer these cables.
i don't know whether these are original HP or just custom made.
by the way i am o.k that they are not USB (unless this has some implication that i better be aware of)

do you have any recommendations...
advises about what to look for ...
any mistakes others did and i shouldn't repeat ....

thank you so much and i appreciate your help

I haven't used one of those in many years (don't have my 48 anymore). The ones with a DB9 connector are simple serial cables (just wires) and unless you have an old computer with a true serial port you'll need to buy a USB to serial adapter.
The cables are typically very reliable (it's just a cable after all), but the USB adapters not so much, you'll have to try one and see if it works (perhaps somebody here already uses a USB to serial adapter that works well and can recommend you a specific brand/model, my PC is old and has a true serial port so I never used one). Some adapter chips only support certain (standard) baud rates on the serial side and while this is normally fine, if you are trying to configure some software that uses some non-standard speeds it won't work. On the other hand, if you can configure your software for something standard (like 9600 8N1) then pretty much all adapters will support it.

On the other hand, you have the cables that are purposedly built with the USB adapter included, which would eliminate all the guesswork (I imagine whoever created them must've made sure it actually works well with the calcs).
Most USB to serial converters use FTDI chips but there's several different versions with different capabilities (see the link). You should try to choose one that doesn't need special drivers and that works with all operating systems, including Linux/BSD/Unix, so that you can plug it anywhere and it will work.