> On Wed, 25 Nov 1998, Brandon S. Allbery KF8NH wrote:
>
> > But we don't. 0.99.14, for example, is noticeably missing from the
> > list --- and I remember 0.99.14 very well because it was the first
> > kernel that was stable enough for production use by most then
> > Linuxers, marred only by small issues such as (IIRC) ATI and S3 video
> > cards vs. COM4. And it's right smack in the middle of the list of
> > released kernels.
>
> Ah yeah, the infamous COM4 bug with S3 chipsets. Seems some fuckwit used
> the usual COM4 I/O port as one of its I/O registers. Ahh, that particular
> chipset designer should have been taken out and made to use Microsoft
> products in eternity (with a Windows 95 Beta!).
>
For your edification, here is the lists of I/O ports used by a S3 Trio64
during BIOS init (collected under an x86 emulator for PPC which registers
all I/O ports ever accessed, so it must be pretty accurate):
0042-0043 /* (Yes it uses one timer)
0061-0061 */
0102-0102
03b4-03b5
03b8-03b8
03c0-03c0
03c2-03c6
03c8-03c9
03cc-03cc
03ce-03cf
03d4-03d5
03da-03da
42e8-42e9 /* Now these ones are interesting: the low order 10 bits
46e8-46e8 * are 0x2e8-0x2e9, which conflicts with standard COM4,
4ae8-4ae8 * because serial boards traditionnally only decode the
82e8-82e9 * 10 low order bits of I/O address. On modern PCI mobo,
86e8-86e9 * the ISA bridge uses so called subtractive decoding
96e8-96e9 * only claiming the cycle if no other device responds
9ae8-9ae9 * which hides the problem. However, IIRC the original
a6e8-a6e9 * culprit is IBM with the 8514/A which was designed (sic)
aae8-aae9 * this way, others only followed. (And this list is only
bae8-bae9 * the list of ports used to init the board in VGA text
bee8-bee9 * mode).
*/
Gabriel
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/