Serial Port TZ 2: Not the BIOS man.

[Aristarco]

I checked out the BIOS form the very beginning, since Ithought it was the reason. But COM2 is enabled and assigned to &H2F8, COM1 to &H3F8. Interrupts to 3 and 4. Ichanged to COM3, COM4, and the combinations in between (COM1,COM4 etc.). Nothing worked. Besides, remember I've changed motherboards. The last one has the COM ports built-in. And everytime I change motherboards I check out the BIOS. This thing is driving me crazy. And as I told you, the only things remaining from the original PC are the enclosure and the power supply. What's wrong? The enclosure? 'cause I measured the PS output and it's +11.43 -12.2 +4.93 and -5.01 with all the devices working (FDD, HDD, COMs and KB). HELP!! Maybe I'll never use it, but I'd like to know to clear up this mistery....

 

[sampbx]

search the web for a com port tst utility anlong with a loop back plug info for the connector you are trying to test I.E. 9 pin or 25 pin. pin on the ribbon cable is marked with a color strip either <font color=red> RED</font> or <font color=Blue> BLUE </font>. The mother board is usually marked with a number <b>1</b> to eliminate confusion, it still can happen when you get fustrated on a problem. the test program will tell you if you have a serial ports configure or not.

 

[edfair]

You have 6.22.&nbsp;&nbsp;Try msd and see what it reports. If it can't find the serial ports then they are probably crippled on the serial card. IDE i/o cards used on 486s generally gave you the option of disabling individual ports. On the motherboard with the built in ports check the voltages on the tx.&nbsp;&nbsp;long row on top. counting left to right. 25 pin check for -12 on 2 against 0 on 7.&nbsp;&nbsp;9 pin -12 on 3 with 0 on 5. It is possible you have bad ribbon connectors.&nbsp;&nbsp;Multiple ways of connecting mb to dconns and board mfgs have been known to package the wrong ones. <p>Ed Fair<br><a href=mailto: > </a><br><a href= > </a><br>