PicStart Plus USB

Thread Starter


Joined Jan 18, 2008
Does anyone know whether the PicStart Plus will work with a serial-to-USB adapter?

I would prefer that solution, rather than an internal serial card. The adapters at my local store are relatively expensive ($30 or more), which is more than I want to spend just to find out.

Thanks. John

Thread Starter


Joined Jan 18, 2008
Thanks. You must have a great memory. It's been 4 years since I looked at the PicStart manual. I will try to remember that detail for the future.

I have been collecting parts for my new PC over the past week or so. Started assembling it today and got a pleasant surprise. The MB has a serial socket on it. All I need to do is run the cable link to the back panel. Don't need to use one of the expansion slots. Will need to use one though for my parallel-only vinyl cutter (Roland/Dr. Stika).



Joined Jul 17, 2007
Re: good memory
Well, I confess that I'd never looked at the Picstart Plus manual before your inquiry, but I'm pretty good at finding manuals and digging out what I need from them ;)

Good news on the mobo serial sockets - but when you're finally configuring the ports, make sure that the IRQs aren't shared with something else. If your mobo has legacy ISA/PCI settings for IRQ assignments, you'll probably have to use them.

The old standard was that COM1/COM3 shared IRQ4, and COM2/COM4 shared IRQ3. Most older PC's only have COM1 and COM2, but if you added an internal modem, it would "want" to go to COM3. This messed up my interface with my UPS communications, as there was an IRQ conflict. I wound up resolving it by manually configuring the modem to COM2/IRQ3, and re-assigning the mobo COM2 to COM3/IRQ4. As long as COM1 and COM3 weren't open at the same time, there wasn't a conflict.

If you just use "plug and pray", you are likely to wind up with problems.


Joined Dec 21, 2010
Hi there,
There are some (Very Very few and old) USB to Serial adaptors that don't work with PICSTART Plus
There are one or two that work but hang very frequently, I had one and in the end threw it away.
Modern ones work fine but you need to set Picstart to find them

1) Install the drivers for the USB to serial adapter using the disk supplied, DON'T let windows do it itself
2) Plug in the adapter and PICSTART Plus
3) go to control panel/system/Device manager look in Ports (Com &LPT) and you'll find the USB to serial device, it'll be COM5 or COM8 or somesuch number.
If you can't see device manager
go to folder options and (in Appearance and Personalization for Windows 7) click the view tab and enable show hidden files and disable hide protected...
4) Now open MPLAB
Select Programmer PICSTART Plus
then enter the COM port number you obtained from step 3

Hope this helps,



Joined Jul 1, 2008
I probably own more USB/Serial converters than most. Six at last count. All of them came with their own drivers and none of them has ever given me a lick of trouble, with the exception of one issue with my Belkin model. The issue is 'Break Mode', which isn't used much any longer in serial communication but my Picaxe Interpreter/Compiler uses it when it's programming the chips. The only other issue, that all converters have, is related only to my VB6 MSComm's 'OutBufferCount' property, which can't be reliably returned from a virtual CommPort.

FYI, all the control and data pins on a USB/Serial converter output + & - 5V. as apposed to the + & - 15V standard of a physical serial port. I have used converters in NullModem configurations between two USB ports, Converter to true RS232 and to my microcontrollers.

When interfacing to the 5V serial I/O of the Picaxe I don't employ a Max232, I just insure (with a 1N914) that the chip doesn't see -5V.

To sum it up.. I like them and I'm thankful they exist.

Thread Starter


Joined Jan 18, 2008
I just noticed this was a thread started by me quite awhile ago. I got the opportunity to compare the serial adapter/port provided on the mobo of an Asus with an aftermarket USB adapter. The Asus adapter did not work with my PicStart Plus. A common aftermarket USB to serial adapter did.

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