I see we have support for the 509B in the tree, but it and the
Ensoniq board won't do the "right thing".  I see a bridge that
NetBSd doesn't seem to know about in the output form dmesg(8); could
this be causing the devices to not be recongnized by the kernel?

This is in a Gateway 2000 E-4200/400 BTW.  dmesg(8)'s output below:

NetBSD 1.3H (GENERIC-NO-EON) #0: Thu Nov  5 09:16:21 EST 1998
    root@:/usr/src/sys/arch/i386/compile/GENERIC-NO-EON
cpu0: family 6 model 5 step 2
cpu0: Intel Pentium II (686-class)
real mem  = 133758976
avail mem = 120950784
using 1658 buffers containing 6791168 bytes of memory
mainbus0 (root)
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o enabled, memory enabled
pchb0 at pci0 dev 0 function 0
pchb0: Intel 82443BX PCI AGP Controller (PAC) (rev. 0x02)
ppb0 at pci0 dev 1 function 0: Intel 82443BX AGP Device (PAC) (rev. 0x02)
pci1 at ppb0 bus 1
pci1: i/o enabled, memory enabled
ATI Technologies product 0x4742 (VGA display, revision 0x5c) at pci1 dev 0 function 0 not configured
pcib0 at pci0 dev 7 function 0
pcib0: Intel 82371AB PCI-to-ISA Bridge (PIIX4) (rev. 0x02)
Intel 82371AB IDE controller (PIIX4) (IDE mass storage, interface 0x80, revision 0x01) at pci0 dev 7 function 1 not configured
uhci0 at pci0 dev 7 function 2: Intel 82371AB USB Host Controller (PIIX4) (rev. 0x01)
uhci0: interrupting at irq 9
uhci0: USB version 1.0
usb0 at uhci0
uhub0 at usb0: Intel UHCI root hub (class 9/1) (rev 1.00/1.00) (addr 1)
Intel 82371AB Power Management Controller (PIIX4) (miscellaneous bridge, revision 0x02) at pci0 dev 7 function 3 not configured
Ensoniq product 0x1371 (audio multimedia, revision 0x04) at pci0 dev 13 function 0 not configured
3Com 3c905B 100Base-TX (ethernet network, revision 0x30) at pci0 dev 14 function 0 not configured
isa0 at pcib0
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
lpt0 at isa0 port 0x378-0x37b irq 7
wdc0 at isa0 port 0x1f0-0x1f7 irq 14
wd0 at wdc0 channel 0 drive 0: <WDC AC26400B>
wd0: using 16-sector pio transfers, lba mode
wd0: 6149MB, 13328 cyl, 15 head, 63 sec, 512 bytes/sect x 12594960 sectors
wd0: using 32-bits pio transfers
wd0: PIO mode 4, DMA mode 2, UDMA mode 2
wdc1 at isa0 port 0x170-0x177 irq 15
atapibus0 at wdc1 channel 0
cd0 at atapibus0 drive 0: <FX322M, , w03> type 5 cdrom removable
cd0: using 32-bits pio transfers
cd0: PIO mode 4, DMA mode 2
we1 at isa0 port 0x300-0x31f iomem 0xcc000-0xcffff irq 10
we1: SMC8216/SMC8216C Ethernet (16-bit)
we1: Ethernet address 00:00:c0:92:03:97
pcppi0 at isa0 port 0x61
midi0 at pcppi0: <PC speaker>
sysbeep0 at pcppi0
isapnp0 at isa0 port 0x279: ISA Plug 'n Play device support
npx0 at isa0 port 0xf0-0xff: using exception 16
pc0 at isa0 port 0x60-0x6f irq 1: color
pc0: console
fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec
isapnp0: no ISA Plug 'n Play devices found
biomask c240 netmask c640 ttymask c6c2
boot device: wd0
root on wd0a dumps on wd0b
root file system type: ffs