For almost the last year I have been on and off trying out a 2.2 Gig 
microdrive working with my jornada 720.

Before all the details are they are kernal tweaks that I can use to get this 
drive to work, such as options for the kernel config to dumb down the ATA 
mode or whatever.

Initially with 1.6.X the drive was barely recognized, the kernal would report 
finding it and then would lose it.

Now with NetBSD 2.0 with sys/arch/hpcarm/hpcarm/softintr.c rev. 1.9 I can boot  
from the drive use it for a while (10mins) before errors pile up and the unit 
freezes, giving I/O errors.
 The Drive performs flawlessly under Win CE I have filled it full of music and 
listen to it continuously.

Details, in the following errors the system has booted from a 32Meg flash CF.  
I have tried with the drive in the CF slot with the same results. (take the 
outside panel off  the flip down tray and your can fit a CFII )

>atactl wd1 identify
Model: GS-Magicstor 1022C              22364d24, Rev: 4d242236, Serial #: 
3148A1960
Device type: ATAPI, removable
Device capabilities:
        LBA
        IORDY operation
        IORDY disabling
Device supports following standards:
ATA-1 ATA-2 ATA-3 ATA-4
Command set support:
        NOP command
        READ BUFFER command
        WRITE BUFFER command
        Host Protected Area feature set
        look-ahead
        write cache
        Security Mode feature set
        SMART feature set
        SET MAX security extension
        CFA feature set
Command sets/features enabled:
        look-ahead
        write cache
        SMART feature set

>dmesg snipplet
wdc1 at pcmcia0 function 0
atabus1 at wdc1 channel 0
wd1 at atabus1 drive 0: <GS-Magicstor 1022C 22364d24>
wd1: drive supports 4-sector PIO transfers, LBA addressing
wd1: 2031 MB, 4128 cyl, 16 head, 63 sec, 512 bytes/sect x 4161315 sectors
wd1: drive supports PIO mode 3, DMA mode 2

>Errors
wdc1:0:0: lost interrupt
        type: ata tc_bcount: 65536 tc_skip: 0
wd1f: device timeout writing fsbn 4000 of 4000-4127 (wd1 bn 1028064; cn 501 tn 
63 sn 0), retrying
wd1: soft error (corrected)



wdc1:0:0: read intr before drq
wd1f: device timeout reading fsbn 208 of 208-223 (wd1 bn 1024272; cn 500 tn 8 
sn 16), retrying
wd1: soft error (corrected)

>This is really strange as the partitition was freshly newfs

dmode ffd0 mode ffd0 dgen 0 gen 0
size ffd0ffd0ffd0ffd0 blocks 0
ino 11140 ipref 2
panic: ffs_valloc: dup alloc
Stopped in pid 151.1 (cp) at    netbsd:cpu_Debugger+0x4:        mov     r15, 
r14

>Rebooted and Fscked

wdc1:0:0: lost interrupt
        type: ata tc_bcount: 8192 tc_skip: 0
wd1f: device timeout reading fsbn 128 of 128-143 (wd1 bn 1024192; cn 500 tn 6 
sn 0), retrying
wd1: soft error (corrected)
BAD SUPER BLOCK: CAN'T FIND SUPERBLOCK

>disklabel -t wd1
magicstor|Automatically generated label:\ 
        :dt=ATAPI:se#512:ns#32:nt#64:sc#2048:nc#2031:\
        :su#4161315:rm#4200:\
        :pa#256000:oa#512064:ta=4.2BSD:ba#8192:fa#1024:\
        :pb#256000:ob#768064:tb=swap:\
        :pc#1536064:oc#512064:\
        :pd#4161315:od#0:\
        :pe#512000:oe#63:te=MSDOS:\
        :pf#3137235:of#1024064:tf=4.2BSD:bf#8192:ff#1024: