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NOTE:   This web site is not some kind of 'official' documentation hub for the XT-IDE card.
It is simply the result of someone who decided to add to the documentation that exists elsewhere.



VCF XT-IDE  -  The History of Hi-Speed Mode  (a.k.a. the 'Chuck mod')


Feb 2011

Early in the life of the XT-IDE card (still at revision 'Rev 1'), Chuck(G) of the Vintage Computer Forums proposed a change to improve performance.

The change had both hardware and software components:

Hardware:  Swap the A0 and A3 address lines going to the IDE device.  See here.
 Software:  Alter the XT-IDE card's BIOS to compensate for the address line swap.

At the time, this change was commonly referred to as the 'Chuck mod'.

Some people modified their 'XT-IDE Rev 1' card, plus made the appropriate hack to the BIOS on the XT-IDE card.  At the time (2011), the BIOS that was hacked would have either been the 'Hargle BIOS' (predates the XUB), or a v1.x.x version of the XUB.


Feb/Mar 2012

Hacking of hardware and software no longer required.

New hardware

'Rev 2' revision of the XT-IDE card released.  Incorporates the 'Chuck mod', later called 'hi-speed' mode.  In fact, there is a set of jumpers that allow the user the choice of running the card in hi-speed mode, or running in 'compatibility' mode (compatible with the XT-IDE Rev 1 card).

New software

Version '2.0.0 beta 1' of the XTIDE Universal BIOS (a.k.a. XUB) released.  Via the 'controller type' configuration option, it caters for both the Rev 1 and Rev 2 cards:

* For Rev 1 cards, the controller type in the XUB is set to '8-bit dual port (XTIDE)'
* For Rev 2 cards jumpered for compatibility mode, the controller type in the XUB is set to '8-bit dual port (XTIDE)'
* For Rev 2 cards jumpered for hi-speed mode, the controller type in the XUB is set to 'XTIDE mod (A0<->A3)'


Sep 2012

Version '2.0.0 beta 2' of the XTIDE Universal BIOS (a.k.a. XUB) released.
In beta 2, the controller types were renamed:

* For Rev 1 cards, the controller type in the XUB is set to 'XTIDE rev 1'
* For Rev 2 cards jumpered for compatibility mode, the controller type in the XUB is set to 'XTIDE rev 1'
* For Rev 2 cards jumpered for hi-speed mode, the controller type in the XUB is set to 'XTIDE rev 2 or modded rev 1'


XT-IDE Derivations

Over the intervening years, there have been many derivations/variations of the XT-IDE card (see here).

The vast majority of those do not have a set of hi-speed/compatibility jumpers.  That is because those cards are hardwired to hi-speed mode.  You set the controller type in the XUB to match your card (e.g. set 'XT-CF PIO8'), and the XUB knows from that, that the card operates in hi-speed mode.