XT-IDE  Rev 3

This is the third revision of the XT-IDE card produced by the Vintage Computer Forums (VCF),  not the first nor second revisions.

Photo / Identification

A photo of an XT-IDE Rev 3 card is here.
Printed on the card is "XT-IDE rev 03".

Early history

MAY/JUN2016: Printed Circuit Board (PCB) developed by glitch.

External links

• The development thread is here.
• Project files are at here.

Changes from Rev 2

• Different switch/jumper settings.
• Although IDE operating mode ('Compatibility'/'Hi-speed') is retained, the jumper settings for it are opposite to those on Rev 2.
• Removed: Optional serial port.
• Removed: Optional Molex power connector.

Hi-Speed mode versus Compatibility mode

Just like with the XT-IDE Rev 2 card, it is expected (only for performance reasons) that the Rev 3 card be jumpered for hi-speed mode, and using a 2.x.x version of the XTIDE Universal BIOS (per option #1 in the table below).

Compatiblity mode changes the IDE interface to how it is on an XT-IDE Rev 1 card.  You will need to jumper your Rev 3 card for this mode if you choose to use a 1.x.x version of the XTIDE Universal BIOS.

The three options for the Rev 3 card are show in the following table:

  Version of
XT Universal BIOS
on Rev 3 card
Jumper setting
of mode
on Rev 3 card
Configure 'device type' option
in 2.x.x XT Universal BIOS
Option #1 2.x.x Hi-speed "XTIDE rev2 or modded rev1"   Best performing option
Option #2 2.x.x Compatibility "XTIDE rev1"  
Option #3 1.x.x Compatibility [ not applicable ]  

Some technical information on this subject is at here.

Switch/jumper settings

A diagram for the IDE functionality is at here
A diagram for the ROM functionality is at here

If you change the base I/O address of the IDE interface, then you will need to reconfigure the associated option of the XTIDE Universal BIOS within the EEPROM (so that the BIOS knows which I/O addresses to use).


Circuit diagram    (PDF version of KiCad file 'XT-IDE.sch')  (diagram dated 14MAY2016)