Information for Tseng Chipset Users : linear memory base address (MemBase) issues : What you should know BEFORE trying another MemBase
Previous: linear memory base address (MemBase) issues
Next: Choosing a MemBase

## 9.1. What you should know BEFORE trying another MemBase

Rule #1: first, let the server find a memory base by itself, without specifying it. Make sure you "sync" all files to disk and close all critical applications. Make sure nothing bad will happen to your filesystems if you have to jump for the power switch soon.

The most critical cards are the ET4000W32p rev a and rev b on VESA local bus (VLB). The server will autodetect a linear base address that doesn't work on all systems.

The least critical cards are PCI-bus cards. The PCI BIOS normally takes care of assigning a good MemBase, and you should never have to deal with all the mumbo-jumbo below.

If the server gets it wrong, you may end up with a severe system crash (e.g. if it maps the video memory right on top of your system memory). If this happens, RESET IMMEDIATELY. Do not try to shut down cleanly, because the X-server, thinking it writes to the VGA memory, will write to system memory instead, and you'll be writing corrupted data to disk. If you did a sync prior to starting the server, there will be no harm done (only a filesystem check which should end up clean). DO NOT attempt to redirect the server output to a file on the system you're testing on (that will write data after you synced).

These are worst-case scenarios, and it is very unlikely this will happen to you. The text above is to make sure you are properly prepared, so that nothing serious happens.

When the server can't find a working linear memory base, it's time to experiment. The rest of this section deals with that.

Information for Tseng Chipset Users : linear memory base address (MemBase) issues : What you should know BEFORE trying another MemBase
Previous: linear memory base address (MemBase) issues
Next: Choosing a MemBase