ide xt hard drives something that most vintage computer enthusiasts
are either unaware of or are told to stay away from
even though you might think it looks like a standard old-school
ide at disk that you found in many computers up until the early 2000s
it's not this is actually an ide xt drive and they only work with 8-bit controllers
it is technically an ide controller but it only runs at 8 bits wide so
it's not compatible with typical ide hard drives there were a handful of
custom drives made at the time that were specifically designed for this interface
and finding one that works today is darn near impossible
that is not standard ide that's 8-bit ide although that's a really cool option to have
built-in and you don't ever see that it's pretty much useless they're real hard to find most of
them are probably unreliable if you find them on ebay they're definitely overpriced don't bother
ide was introduced around 1989 and depending on who you ask it either stands for integrated drive
electronics or intelligent drive electronics and then later when they started introducing
ide cd-rom drives and zip drives and other things the d in it changed from drive to device it was
also generally known as ata for at attachment the at being named after the ibm at computer or
more specifically parallel ata when it became necessary to differentiate it from serial ata
but these drives and controller cards i have here are not ata because they
are not designed for the 16-bit at bus these are 8-bit drives and controllers
designed for xt class computers so that's why these are known as ide xt or xta hard drives
however these drives are not to be confused with the xt ide which is a currently available
open source interface card that lets you use modern or least semi-modern ide hard drives
and compact flash cards with vintage pcs despite the similar name the ide xt drives
i'm showing in this video will not work with one of these modern xt ide interface cards
here's the first drive i have which i already demonstrated the interesting
noises it makes it's a western digital wd 93028-x they also made an at version
of this but the xt version has that dash x on the end it was made in 1991
the next one is a seagate st 325 x this is another 20 megabyte hard drive just like that
western digital and it was made in the 27th week of 1990 and finally here is the seagate
st 351 a slash x now as that model number indicates this is actually switchable
between a 16-bit at interface and an 8-bit xt interface this is a 40-megabyte hard drive
and it was made in the 27th week of 1991 and by the way i believe these st 351 a slash
x drives were both the last 40 megabyte hard drives ever made and the last stepper motor
hard drives ever made i believe these were available until at least 1994.
in addition to western digital and seagate ide
xt hard drives were also made by connor epson and miniscribe
and here's the first of the two controller cards i have or actually these are not necessarily
controller cards because as the name integrated drive electronics indicates the controller is
built into the electronics of the drive and this is really just an interface between the
computer's bus and the drive so this is an ide xt interface card this one is a western digital wd
xt-150 you can see the copyright date of 1988 it was made in the 24th week of 1989.
one different thing about these xt interfaces compared to 80 ide interfaces is that
the two hard drives get individual connectors they're not both daisy chained off the same cable
so you get one connector and one cable for each drive if you have two hard drives connected
that's the same thing with the seagate st05x interface card two connectors for
the two drives this one looks quite a bit more advanced because it uses surface mount chips
this unused pin out is for an optional floppy drive controller that would also have a controller
chip here but this is not equipped with that and it was made in the 36th week of 1991.
another thing both of these cards have is an onboard power connector because they were
designed to be used as hard cards where the hard drive would be mounted on the same bracket as the
interface card and it would get its power from the card rather than the computer's power supply
there are also some computers with an ide xt interface built into the motherboard especially
in the european market where xt class machines had a longer shelf life than in north america but here
in the us tandy used ide xd hard drives in their later tandy 1000 machines here is a tandy 1000 rlx
and it has an onboard ide xt hard drive interface which tandy called their smart drive interface
a different version of ide xt was used in the low end ibm ps1 and ps2 machines and in the
sega terra drive which was built for sega by ibm these drives have a 44 cartage connector
which provides power to the drive through the interface cable ide xt drives were also
used with the commodore amiga 500 computer and the a590 external hard drive attachment
and despite the notion of ide xt being a proprietary interface there is actually
some cross compatibility between different brands
for example the built-in interface in this tandy will work with either western digital or c8 hard
drives and i've tested it and this western digital interface card works fine of these seagate drives
however one quirk with that cross compatibility is that you may need to change a jumper setting
depending on if the interface you're using requires the bus reset to be active high or
active low for example with this seagate st 325 x drive setting this jumper to the outer position
sets the bus reset to active high while changing the jumper to the middle position
sets the bus reset to active low so if you get one of these drives and it doesn't seem to work
and it may not even spin up at all if you have this in the wrong position
try changing that jumper and that may fix the problem
also these ide xt interfaces will not work with a compact flash adapter even though some compact
flash cards can be switched into an 8-bit mode it's still not compatible or at least i've never
heard of anyone being able to get it to work which is a shame because many of these ide xt
interfaces were used in low-profile all-in-one and laptop computers which either only have one
isa expansion slot like this tandy or don't have any expansion slots at all which would make it
impossible to use a modern and readily available xtcf card adapter or with this tandy i would
need to use up the only slot it has which i would rather put in something like a sound blaster card
so here's my first test of the western digital drive connected to the tandy's
built-in smart drive interface so i'll turn it on
boots right up into dos and it works fine this western digital drive is not auto parking
whereas the two seagate drives are so if you plan to move it you have to manually park the heads
before you shut off the power so i have a program here which will do that and now i can turn it off
and here's the seagate st 351 a slash x drive working with the onboard smart drive interface
which should be no surprise that it works because it's what the computer came with originally
as you can see i have more stuff installed on this drive because it's the drive i have
normally in this computer the seeking sound on this drive is quite a bit more scratchy sounding
than the western digital drive but it's also a lot faster
the random seek time with this st 351a slash x drive is 24.77 milliseconds
which is actually better than the 28 milliseconds it's rated at
and for comparison the western digital drive is over 70 milliseconds
data transfer rate of 325.6 kilobytes per second which is pretty good for an 8-bit xt interface
now even though this tandy has a built-in ide xt hard drive interface on the motherboard
you can still use an isa card hard drive interface so i have the western digital card
installed and connected to the seagate drive
so this is the seagate drive with the western digital isa card interface and
again everything works fine this time i'll use pc tool system information to measure the performance
actually the average seek time was even better this time at 21.03 milliseconds
data transfer rate 207 kilobytes per second which was not as good as the built-in interface
and at least on tandy systems these drives do have a sleep feature
tandy supplied a small utility called hd spin which takes up about 1k of ram
and it automatically shuts off the hard drive after 10 minutes of inactivity
and now the hard drive has shut off but if i issue a command which
accesses the disk you'll hear it spin up again
and this drive does auto park so when i'm done i can just turn it off
another unique thing about these drives is that it is actually possible to low level format them
which is something you're told to never try to do to an ide at hard drive but for these xt ide
hard drives when he first install them you actually do need to low level format them
both of these interface cards have a rom chip with that low level format program
on them accessed by typing in a command to the dos debug program
here's that 20 megabyte seagate drive and it
has one of the best hard drive spin up sounds i've ever heard
and the way you do a low level format with it is to enter the dos debug command
and then type g equals c 800 colon 5 and hit enter and now we're in the ide super bios revision 1.0
copyright western digital 1988 current drive is c and that's fine so i'll just hit enter
current interleave is three these eight bit interface cards generally cannot go below
three to one interleave so i'll just leave it set to that it asks you if you want to
dynamically configure the drive i'll say yes and here has a whole bunch of parameters but
the only ones we need to worry about are the cylinders and heads so for this drive
it has 615 cylinders and four heads or at least that's what it pretends to have because these
drives actually do sector translation just like modern ide hard drives so even though it only
has a single platter and actually only two heads it pretends it has four heads and 615 cylinders
because that was the most common parameters for a 20 megabyte hard drive
so enter 615 cylinders and four heads and hit enter it asks you if you want to virtually
configure the drive i just say no and now it's ready to begin formatting with interleave 3
and i'll just say yes and now it's formatting and i'll come back in a couple minutes when it's done
and now it's done it asks if you want to format bad tracks
that's if you have one of these western digital drives which actually lists the bad
tracks on the drive itself but these seagate drives don't so i'll just say no
and format was successful put dos disk in a and hit any key when ready now it's going to reboot
and from this point on it's pretty much standard fare for formatting a hard drive first you do
fdisk and then you do format here's fdisk and i'll do create dos partition create a primary partition
it asks if you want to use the maximum available size and set active you just say yes
and now restart again and now we'll do the format
and here it is formatting 20.37 megabytes and now the format is complete and there are no bad
sectors so now when we restart it'll start up from the hard drive
there it goes we have a c prompt with 21 million 176 320 bytes free
these western digital drives do have a well earned reputation for unreliability
you can often get them working again by oiling the stepper motor but that does not always work
and it may not be a permanent solution however the seagate drives are surprisingly reliable
i have five of them in total two of the 20 megabyte versions
and three of these 40 megabyte versions and they all work perfectly with no bad sectors
so that's about it for these ide xd hard drives and interface cards i just wanted
to demonstrate that they do exist they're not as uncommon as you might think and many of them are
still working perfectly fine today and in case you're looking for one i'll include a link to
a web page i uploaded with a list of all the known makes and models of ide xt hard drives