VCF 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 nor fourth revisions.
Photo / Identification
A photo of an XT-IDE Rev 3 card is here.
Printed on the card is "XT-IDE rev 03".
Before reading further, read the web page at here, to gain information on the basics of the XT-IDE.
History of Rev 3
JUN2016: Printed Circuit Board (PCB) developed by glitch.
OCT2017: Superceded by the Rev 4
• 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 (specifically, its register map) 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, or you have an Olivetti M24 or AT&T PC6300.
• The three options for the Rev 3 card are show in the following table:
Some technical information on this subject is at here.
A diagram for the IDE functionality is at here
A diagram for the ROM functionality is at here
On the card, if you change the base I/O address of the IDE interface from the default of 300 (hex), then you will need to reflect that change within the XTIDE Universal BIOS within the EEPROM (so that the BIOS knows which I/O addresses to use).
For example, the applicable area of the configuration/flashing tool for version 1.1.5 of the XTIDE Universal BIOS is shown at here.
Circuit diagram (PDF version of KiCad file 'XT-IDE.sch') (diagram dated 14MAY2016)