Difference between revisions of "COM Ports and Related Hardware in Windows"

Latest revision as of 12:57, 17 October 2008

STANDARD COM PORT & MODEM SETTINGS + KERMIT TERMINAL FOR DOS

Typically on 486 hardware with Windows 95:

• mouse on com 2
• modem on com 3

Standard COM and LPT port addressing for Windows 3.1/3.11/95/95OSR2/95OSR2.5/98/98SE

• onboard com1: 3f8 irq4
• onboard com2: 2f8 irq3
• parallel  : 378 irq7

-for more on com ports see "mcom.txt"

MODEM

• COM: 3 IRQ: 4

HOW TO USE KERMIT TO TEST COM PORTS:

>set po 1 	(set onboard port 1)
>set ba 1200	(set baud 1200)
>c		(terminal mode)
<alt>-X		(exit terminal mode)
1200 good for testing mouse

HOW TO USE DEBUG TO TEST COM PORTS

debug
-d 40:0

IDE ADDRESSES (HARDDRIVES AND CD ROM DRIVERS)

            address, irq
primary     1F0,     14
secondary   170,     15
tertiary    1E8,     11
quadriary   168,     12

Troubleshooting Ports and Windows

SYSTEMS FINDS TWO GAME PORTS, TWO WAV OR SOUND DEVICES

This system has a sound card and a modem as two seperate cards but they are connected by an audio cable.

System kept finding two of each device, solution:

under INTERGRAGED PERIPHERIALS in award bios change:

• PCI slot IDE two channel: DISABLED
• Onboard Gameport: DISABLED

• Onboard Parallel Mode: ECP+EPP (bad)
• Onboard Parallel Mode: EPP (bad)

• ECP Enhanced Communications Port
• EPP Enhanced Parallel Port
• SPP Standard Parallel Port

SYSTEM FREEZES DURING WIN95 LOADING, RUNS FINE WHEN REMOVE MODEM

I've seen this with the Logicode 8bit modem card. The system would not load win95 or would return "invalid operating system". When the modem was removed, it booted fine.

solution:

• adjusted following settings in cmos
• Onboard Serial Port 1: com3/3e8
• Onboard Serial Port 2: com2/2f8
• before the Port 1: was set to com1, causing a conflict with the modem on com 1. Usually this just makes the PnP modem not recognized by windows 95, but sometimes it actually locks up the maching on boot.

MODERN PCI SOUNDBLASTER LEGACY SUPPORT, NO SOUND IN SOME MS-DOS GAMES

updated: Sat Feb 3 11:28:26 CST 2001

These are general tips for configuring most Creative Labs sound cards to work for legacy support of audio in games (such as DOOM).

• .) usually modifying DMA and IRQ settings in the autoexec.bat file is useless,

since the software drivers will change them back on reboot.

• .) usually you can not modify IRQ and ADDR settings from windowze. "This resource

cannot be modified" will appear if you try from the system properties.

• .) modification of the sound card IRQ can best be accomplished from the bios. Disable

an IRQ or change it to ISA/Legacy and the PCI card will not be able to use it and thus relocate to another available IRQ, sometimes even moving other devices out of the way.

• .) the afore mentioned is NOT NECESSARY to get the IRQ you desire for your legacy

MS-DOS game such as DOOM. The Windowze PCI IRQ is NOT THE SAME as the legacy device IRQ available in MS-DOS. Goto a command prompt and type "set" to view those settings or on many Creative Labs cards you may view it from the device properties "Legacy Audio Device" under Windowze. A tab labeled "DOS Application Settings" will display those resources.

• .) so far I have found no way to modify the "DOS Application Settings" including editing

the set line in autoexec.bat (which just resets such as was suggested above).

• .) observe the 8 bit DMA IRQ and use it for old games such as DOOM. DOOM defaults to

IRQ3 for this, but often the new SB legacy suppt is set to IRQ1.

• .) Do not use the 16bit IRQ unless you know for sure the game supports it; DOOM doesn't.
• .) You may use midi for the game's music by selecting the same address as assigned to

the port. This seems to work fine in DOOM as well as just selecting Sound Blaster.