CompuServe Thread

Forum unknown · Modems & Comm Q&A

#Interrupt Help

3 messages in this thread
#26113From: Bob GaudioOct 26, 1991 7:04 AM
int). I tried to logon to your (818) 706-2467 BBS at 9600 using PCPLUS, but I had no luck getting hooked up. I also am having difficulty using the internal modem. There seems to be a conflict between the 'mouse (com1) and the modem (I tried Com1 and Com3). I expect \that the difficulty is assocviated with the sharing of IRQ3 — I could not find any reference in your manual to how I can change the interrupt setting for the modem. Can this be done? I would like to set it to IRQ5. I have had to do this for my 2400 baud modem to keep it out of the way of other peripherals and Windows. I'll be looking forward to your reply. Thanks in advance for the help!
#26119From: Paul E. Hansen [SysOp]Oct 26, 1991 3:19 PM
In the XT/AT environment the standard addresses and IRQs are: COM1 03F8 IRQ4 COM2 02F8 IRQ3 COM3 03E8 IRQ4 COM4 02E8 IRQ3 Note that COM1 and COM3 share IRQ4, while COM2 and COM4 share IRQ3. This is 'built into' the original IBM architecture. (Actually, only COM1 and COM2 were originally defined.) All of PPI internal modems are set to function at the standard addresses and interrupts shown above. There is no way to alter the IRQ or address in the modem. If you have a mouse on COM1, then you cannot use a modem on COM3, it must either be mapped to COM2 or COM4. If you already have a serial port installed in your computer at COM2, then the only place to install the internal modem is as COM4 in your situation. If you have a conflict with another device, then the usual symptom is that you may be able to dial out with the modem, but nothing will appear on the screen once a connection is made. You will have to be a bit more definitive in your description of the problem you have had in calling the PPI BBS before I can attempt to determine why you might be having a problem.
#26119From: Paul E. Hansen [SysOp]Oct 26, 1991 3:19 PM
In the XT/AT environment the standard addresses and IRQs are: COM1 03F8 IRQ4 COM2 02F8 IRQ3 COM3 03E8 IRQ4 COM4 02E8 IRQ3 Note that COM1 and COM3 share IRQ4, while COM2 and COM4 share IRQ3. This is 'built into' the original IBM architecture. (Actually, only COM1 and COM2 were originally defined.) All of PPI internal modems are set to function at the standard addresses and interrupts shown above. There is no way to alter the IRQ or address in the modem. If you have a mouse on COM1, then you cannot use a modem on COM3, it must either be mapped to COM2 or COM4. If you already have a serial port installed in your computer at COM2, then the only place to install the internal modem is as COM4 in your situation. If you have a conflict with another device, then the usual symptom is that you may be able to dial out with the modem, but nothing will appear on the screen once a connection is made. You will have to be a bit more definitive in your description of the problem you have had in calling the PPI BBS before I can attempt to determine why you might be having a problem.