Is there a hex value for "750Hz" in usbport.sys?

marzsyndrome · Post by **marzsyndrome** » Thu Jun 11, 2009 1:19 pm

I've seen values for 250Hz, 500Hz and 1000Hz, but why not 750Hz? Is it viable/possible?

I'm not very good at translating numbers into hex code myself unfortunately.

Post by **5eraph** » Thu Jun 11, 2009 1:38 pm

Change the View of Microsoft's Calculator application to Scientific to convert numeric bases:

0250 base 10 == 00FA base 16
0500 base 10 == 01F4 base 16
0750 base 10 == 02EE base 16
1000 base 10 == 03E8 base 16

marzsyndrome · Post by **marzsyndrome** » Thu Jun 11, 2009 3:03 pm

Erm, I've not used the scienfific calculator before. How do you do 'base' and all that?

Also, if you've already given the answers in your post, then maybe something else has to be translated because, for instance, the hex value for 250Hz is "B0 04 73 09 52 8A 02 01", yet there's no instance of "00FA" anywhere. How confusing.

alur · Post by **alur** » Thu Jun 11, 2009 4:11 pm

I don't think it's possible. If I remember correctly it's a delay that is specified, and not specifically a Hz. So 1ms -> 1000Hz, 2ms -> 500Hz, and 750Hz would be somewhere in-between.

Post by **user_hidden** » Thu Jun 11, 2009 4:13 pm

what 5eraph is saying is open microsoft calculator.
make sure the setting is Dec and enter 250.
then click the radio button for Hex and voila converted to FA.

what we are showing is a dec to hex converstion.

Post by **5eraph** » Thu Jun 11, 2009 5:15 pm

Can somebody repost all of the USBPort addons so I could have a look? They have not been officially available from Zacam's post for nearly a year and a half.

marzsyndrome · Post by **marzsyndrome** » Thu Jun 11, 2009 8:49 pm

I have modified versions of the addons where I added a few more driver versions post-discontinuation, if those are good enough?

Post by **5eraph** » Thu Jun 11, 2009 9:20 pm

That should be fine as long as you've clearly labeled your modifications.

code65536 · Post by **code65536** » Thu Jun 11, 2009 10:42 pm

Are you sure about the "52 8A 02" part of the change? Because if you're editing what I think you are editing, that doesn't look very kosher...

In any case, alur is right, it's a millisecond interval. The key is the "B0 04", which, if this change is being made where I think it's being made, corresponds to a "MOV AL,4" op.