It's a XTA (8-bit IDE) hard drive, so no it won't work in a 486 or higher as the IDE interface that was mostly used in computers was ATA (16-bit IDE/EIDE).

Unless you have a 8-bit XTA card which I'm not sure will even work on a 16-bit PC.

thanks, you are right...

Vynix wrote:

Unless you have a 8-bit XTA card which I'm not sure will even work on a 16-bit PC.

XTA controllers do work in 16-bit ISA slot.
I successfully ran such a thing in a 386.

As far as I know, ATA is mostly 16 bit ISA on a cable, so I believe XTA is more or less 8-bit ISA on a cable, so ATA should be backward compatible with XTA ?

Deksor wrote:

As far as I know, ATA is mostly 16 bit ISA on a cable, so I believe XTA is more or less 8-bit ISA on a cable, so ATA should be backward compatible with XTA ?

ATA is more than 16-bit ISA on a cable, it's also the register set compatible with that WDC-based controller from IBM 5170.
XTA has different register set.

There are HDDs compatible with both XTA and ATA, but the mode must be selected with a jumper.

Grzyb wrote:

There are HDDs compatible with both XTA and ATA, but the mode must be selected with a jumper.

One such drive would be the Seagate ST351A/X, although its jumper settings can be quite unsettling: https://stason.org/TULARC/pc/hard-drives-hdd/ … -SL-IDE-AT.html

Grzyb wrote:

Deksor wrote:

As far as I know, ATA is mostly 16 bit ISA on a cable, so I believe XTA is more or less 8-bit ISA on a cable, so ATA should be backward compatible with XTA ?

ATA is more than 16-bit ISA on a cable, it's also the register set compatible with that WDC-based controller from IBM 5170.
XTA has different register set.

Well, yes and no. 😀 The original hardware for ATA-0 aka IDE or AT-Bus (not EIDE) is just a glue logic without any intelligence (just buffers/an address logic).
Here, the smart part resides in the PC/AT BIOS (speaks WD1003 language) and the HDD electronics itself (emulates WD100x logic).

That's in contrast to on-board ATA controllers found on PCI motherboards. They contain parts of the ATA logic.
The older MFM/RLL Shugart interfaces, on the other hand, incorperating a real WD100x interface chip (8-Bit boards often had an on-board BIOS).

Also, ESDI was an in-between of IDE and old Shugart MFM/RLL interfaces.
It contained about 2/3 of its intelligence on the controller and 1/3 on the fixed disk.

AT-Bus/ATA-0/IDE also was used for other tasks, such as interfacing EPROM programmers.
The drawback in comparison to full ISA is, that it is limited to a fixed I/O range and I/O ports (how was Multi-Word DMA done, then ? 😕 ).

Edit: Some typos fixed.
Edit: If you meant to say "ATA as a whole is more than 16-bit ISA on a cable", then you're fully correct, of course. My bad. 😊

Grzyb wrote:

Vynix wrote:

Unless you have a 8-bit XTA card which I'm not sure will even work on a 16-bit PC.

XTA controllers do work in 16-bit ISA slot.
I successfully ran such a thing in a 386.

Any 8-bit ISA card will run in 16-bit slot, why wouldn't it? It HAS to. Because 16-bit slot is 8-bit slot with additional address, data, irq and drq lines which are simply not used when no card is installed.

Also if this XTA drive works - it's a little gem there. Those drives are kind of rare and terribly expensive. Excellent for machines like Commodore Colt / PC10-III and such...

Jo22 wrote:

AT-Bus/ATA-0/IDE also was used for other tasks, such as interfacing EPROM programmers.
The drawback in comparison to full ISA is, that it is limited to a fixed I/O range and I/O ports (how was Multi-Word DMA done, then ? 😕 ).

ATA-0 only has PIO mode 0.
Multi-word DMA was added with ATA-1, most likely with VLB/PCI controllers.

Edit: If you meant to say "ATA as a whole is more than 16-bit ISA on a cable", then you're fully correct, of course. My bad. 😊

That's exactly what I meant.
At the card side, both XTA and the original ATA are just address decoders and tristate buffers.
At the drive side, however, there's the register set - different between XTA and ATA.

HanJammer wrote:

Grzyb wrote:

XTA controllers do work in 16-bit ISA slot.
I successfully ran such a thing in a 386.

Any 8-bit ISA card will run in 16-bit slot, why wouldn't it? It HAS to. Because 16-bit slot is 8-bit slot with additional address, data, irq and drq lines which are simply not used when no card is installed.

It seems you quite often don't reply to what was actually written. 😉 He did not even mention "8-bit cards". XTA controllers are 8-bit, yes, but the point is that they use different registers and i/o ports than what an AT-class machine would use for accessing hard disks. So normally, the BIOS of anything with 16-bit ISA slots isn't able to use XTA, unless the XTA card has it's own BIOS, since it would only probe the i/o ports for ATA.

Apart from that and as for your question "why wouldn't it?", there were indeed 8-bit cards made for the XT that won't work in a 16-bit ISA slot. Note that the 8-bit slots of the XT were not "ISA" yet. They run at 4.77 MHz, whereas the slowest AT with 16-bit ISA drove its slots with 6 MHz first, 8 MHz later. Quite a few early XT cards won't work at that speed. Not even every 16-bit card works in every 16-bit slot. Some (mainly VGA cards) rely on the 14.318 MHz clock from the mainboard, which at some point was no longer present on many, causing such cards not to work.

so guys the bottom line is it will start and run on my 16bit pc or not? 😀

derSammler wrote:

[...]
It seems you quite often don't reply to what was actually written. 😉 He did not even mention "8-bit cards". XTA controllers are 8-bit, yes, but the point is that they use different registers and i/o ports than what an AT-class machine would use for accessing hard disks. So normally, the BIOS of anything with 16-bit ISA slots isn't able to use XTA, unless the XTA card has it's own BIOS, since it would only probe the i/o ports for ATA.

XT BIOS doesn't do storage, so XTA (and MFM and SCSI) cards all need and have their own BIOSs, so by definiton it will. HDD support in BIOS was only added in the AT.

retropol wrote:

so guys the bottom line is it will start and run on my 16bit pc or not? 😀

If you have the corresponding 8 bit XTA adapter, it will.

derSammler wrote:

So normally, the BIOS of anything with 16-bit ISA slots isn't able to use XTA, unless the XTA card has it's own BIOS, since it would only probe the i/o ports for ATA.

Probably all XTA cards come with BIOS.

retropol wrote:

so guys the bottom line is it will start and run on my 16bit pc or not?

It will, if you have an appropriate controller card, eg. Seagate ST05X
General procedure of running XT-style controllers in AT machines applies: in CMOS setup, set the drive type to "none".

Grzyb wrote:

Probably all XTA cards come with BIOS.

Only if they were made for the original IBM PC. A couple of XT clones had XTA interface cards with no own BIOS, as the BIOS on the mainboard had support built-in.

retropol wrote on 2019-10-27, 08:19:

so guys the bottom line is it will start and run on my 16bit pc or not? 😀

It should work with 16-bit multi IO board, that support 8-bit IDE hard disks. Prime 2 boards and Hualon (HMS) IO board support 8-bit IDE mode and could be configured with jumpers for specific XT IO