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Hard Drive Interfaces: XT-IDE vs. AT-IDE

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dvanaria

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I have an 8-bit hard disk controller in a free ISA slot in an XT-class PC that I'm trying to revive. The controller is made by Western Digital (there's a sticker on it that says 61-000347-00).

This controller uses a 40-pin cable to connect to a hard drive (an IDE interface). I believe this would be classified as an XT-IDE controller, but is that only because it's 8-bit? IDE is the interface, meaning 40-pin cable, so I should be able to connect any IDE drive to this controller. Or do I need to find an "XT-IDE" drive as opposed to an "AT-IDE" drive? The one I'm thinking of using is a 120 MB Maxtor which also has an IDE interface.

Thanks for any help you can give me on this.
 
If the interface card is a WDXT-140 or WDXT-150, as shown below, then yes, it is IDE-XT, or XT-IDE, however you want to say it, and was meant to work with IDE-XT hard drives such as the Western Digital 93028X (or any other WD drive with a model number ending with "X").

However, this should not be confused with the so-called "XT-IDE" card talked about on this forum, which is actually an IDE-AT (a.k.a. ATA, PATA) controller for XT-class 8-bit ISA bus machines, and will NOT work with the original, true 8-bit IDE-XT drives (except the Seagate ST-351A/X, which can be switched into IDE-AT mode by changing a jumper setting).

2dakolk.jpg
 
JFYI
http://www.vintage-computer.com/vcforum/showwiki.php?title=Systems:Commodore+PC10-III
--> Hard Drives
A short list of compatible XTA drives.

You can also trace a wire from the 40-pin connector to the ISA edge connector,
AFAIK, XTA uses DRQ3 (ISA B16) and ^DACK3 (ISA B15)

XTA pinout:
Code: 
RST      B1    A1 GND 
SD7      B2    A2 GND
SD6      B3    A3 GND
SD5      B4    A4 GND
SD4      B5    A5 GND
SD3      B6    A6 GND
SD2      B7    A7 GND
SD1      B8    A8 GND
SD0      B9    A9 GND
^CS1     B10  A10 GND
AEN      B11  A11 GND
^IOW     B12  A12 GND
^IOR     B13  A13 GND
^DACK3   B14  A14 GND
DRQ3     B15  A15 GND
IRQ5     B16  A16 GND
A1       B17  A17 RSVD
A0       B18  A18 GND
^PRICS   B19  A19 GND
^ACTIVE  B20  A20 GND

AFIK, XTA internally is fully compatible with WD-1002AX family of controllers
and resides at the address 0x320 (and 0x324 for the secondary controller).
 
I have bought that same WD 150 controller on ebay.. Tried to connecting it with a 213MB harddisk.. But harddisk doesnt work.. Seems that this controller is limited for only small sizes older types ide harddisk..

On stason.org there the data sheet for this controller:

http://www.stason.org/TULARC/pc/har...-One-IDE-XT-interface-d-226.html#.UmbipBDNPQM

Maximum heads/cyl.: 8 heads and 1024 cylinders so i dont know how large the harddisk could be.. But maximum size of 8 heads and 1024 cylinders seems very limited to me..
 
Robin4 said:
I have bought that same WD 150 controller on ebay.. Tried to connecting it with a 213MB harddisk.. But harddisk doesnt work.. Seems that this controller is limited for only small sizes older types ide harddisk..

On stason.org there the data sheet for this controller:

http://www.stason.org/TULARC/pc/har...-One-IDE-XT-interface-d-226.html#.UmbipBDNPQM

Maximum heads/cyl.: 8 heads and 1024 cylinders so i dont know how large the harddisk could be.. But maximum size of 8 heads and 1024 cylinders seems very limited to me..
Click to expand...
I doubt that there is an XT-IDE drive that exceeds those parameters. And I'll bet that 213MB drive you couldn't get to work wasn't an XT-IDE drive but rather an AT-IDE drive and none of them will work with this controller as previously stated above.
 
The only IDE-XT drives I've seen are 20, 30, or 40 MB (give or take a few MBs).

Western Digital IDE-XT drives:

Code: 
XT Hard Disk Drives

   Model     Cap     Cyl     WPC     Hd     LZone   Access   spt     Total

WD-93028-X   21.4    615     615     4       616      70     17      41820
WD-93038-X   32.1    615     615     6       616      70     17      62730
WD-93048-X   42.5    977     977     5       978      70     17      83045
WD-93024-X   21.4    615     615     4       616      39     17      41820
WD-93034-X   32.1    615     615     6       616      39     17      62790 
WD-93044-X   42.5    977     977     5       978      39     17      83045
WD-95028-X   21.4    615     615     4       616      70     17      41820
WD-95038-X   32.1    615     615     6       616      70     17      62730
WD-95048-X   42.5    977     977     5       978      70     17      83045
WD-95024-X   21.4    615     615     4       616      39     17      41820
WD-95034-X   32.1    615     615     6       616      39     17      62730
WD-95044-X   42.5    977     977     5       978      39     17      83045

Other IDE-XT drives:

Miniscribe 8225XT (20 MB)
Miniscribe 8450XT (40 MB)

Seagate ST-325X (20 MB)
Seagate ST-325A/X (20 MB, combination XT/AT IDE)
Seagate ST-351X (40 MB)
Seagate ST-351A/X (40 MB, combination XT/AT IDE)
 
I have a Western Digital WD93028-X drive. This is such a XT IDE drive. Would I have to find a special controller to read the drive or can an adapter somehow be constructed to access it with a 16bit controller?

Would love to see if there are some good games on it...
 
There are several pinouts for 8-bit 'XTA' hard disks - I'd confirm for sure what you're dealing with, before plugging it in to a 16-bit IDE interface!
 
Yes, but you need the BIOS to support it. You could try the XTIDE Universal BIOS with '16 bit adapter in 8-bit slot' mode, but you'll need to patch it to not check the status of the ATA 8-bit mode set command (if indeed, it does check it). Also XTA drives may not even implement identify device, which would stop the BIOS from working, and also at least some 8-bit interfaces don't provide A2, which also will stop it from working.
 
I actually never heard of this old standard until I noticed it didn't work. I own a XTIDE controller (the modern and wrong kind for this), maybe I can modify the bios of that thing if that's what causes the issue.
 
That should be possible, provided the drive is of the type that has the same pin-out (except for D8..D15 being n/c or ground). If that's the case, you can use debug to confirm the drive is responding by checking the register values.
 
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