The Glitch Works XT-IDE rev 4 is an open-source 8-bit ISA IDE controller board that enables the use of modern 16-bit IDE devices (CompactFlash adapters, DOM modules, hard drives) on vintage IBM PC/XT, AT, and compatible systems. Designed in KiCad and licensed under GNU GPL v3.0, the rev 4 improves on the rev 3 with better silkscreen, larger jumper pads, corrected latch read/write timing, additional Slot 8 Support test points, and consistent parts numbering for easier kit assembly. When paired with the XTID

Bus Interface

8-bit ISA (fits any PC/XT/AT 8-bit slot)

Storage Media

IDE/ATA — CompactFlash via adapter, DOM, or standard IDE hard drive

Design Tool

KiCad (fully open-source EDA)

License

GNU GPL v3.0

PCB

2-layer, ISA form factor, through-hole components

DIP Switch Banks

2x CTS 208-8 (8-position each) for address configuration

EEPROM

AT28C64B (8KB, 28-pin DIP) — in-system programmable

Bus Transceivers

2x 74LS245 octal bidirectional transceivers

Latches

2x 74F573 octal transparent latches

Address Decoders

2x 74LS688 8-bit magnitude comparators

Logic ICs

74LS138 3-to-8 decoder, 2x 74LS04 hex inverter, 74LS32 quad OR gate

Pull-up Networks

2x 10Kx9 SIP resistor networks (RP1, RP2)

Bypass Capacitors

11x 0.1uF axial ceramic + 1x 100uF 6.3V electrolytic

Activity LED

HP HLMP-3507 with 470R current limiting resistors

BIOS

XTIDE Universal BIOS — GPLv2, supports up to 4 IDE controllers

Revision

Rev 4 (2017) — improved timing, silkscreen, and Slot 8 test points

Clock profile switcher for timing-sensitive software and test harnesses, enabling controlled transitions between true legacy rates and turbo operation.

Profiles

4.77MHz, 8MHz, 12MHz, board turbo

Switching Logic

Debounced hardware line with deterministic latch state

Feedback

Status LED map plus software verification hooks

Compatibility

AT clones, 386SX, selected 486DX boards

Use Cases

Cycle-sensitive DOS software and diagnostics harnesses

Field Harness

Front-panel and relay control compatible