[ HISTORICAL SYSTEM BOARD // IDENTIFIED MODEL ]
Chaintech 4SPI
Socket 3 PCI/ISA 486 motherboard, early-to-mid 1990s. This record distinguishes the exact model from related variants and requires revision-matched documentation for service.
IDENTIFY THE PCB: Record model suffix, board revision, chipset markings, BIOS label and date codes before applying any family-level compatibility information.
Model specifications
| Exact model | Chaintech 4SPI |
|---|---|
| Generation / chipset | Socket 3 PCI/ISA 486 motherboard, early-to-mid 1990s; PCI/ISA 486 chipset family; identify chipset markings on the unit and use the matching Chaintech manual revision. |
| CPU socket / processor | Socket 3 486 SX/DX/DX2/DX4 family where processor voltage, clock and BIOS revision are supported by the exact 4SPI PCB. |
| RAM technology / capacity | 72-pin SIMM FPM DRAM; capacity and parity support depend on module density and bank population in the 4SPI manual. |
| Form factor | Baby AT. |
| Bus, slots & I/O | PCI and 16-bit ISA expansion; IDE, floppy, serial, parallel and keyboard interfaces. Match exact header/slot layout and I/O pinouts to the PCB revision. |
| Jumpers / BIOS compatibility | BIOS CPU support, memory configuration and system clock are revision-dependent. Record ROM vendor/version and follow only the 4SPI CPU/clock jumper table. |
Jumper, BIOS & compatibility notes
Do not infer compatibility from the similar 4SPI2 designation. Confirm board suffix/revision and exact manual before installing a DX4 or setting CPU voltage.
BIOS CPU support, memory configuration and system clock are revision-dependent. Record ROM vendor/version and follow only the 4SPI CPU/clock jumper table. Matching socket or connector geometry alone does not establish CPU, memory or firmware compatibility.
Safety & preservation
Use ESD-safe service and inspect battery/corrosion, SIMM contacts, socket and capacitors. Photograph settings before work and confirm AT P8/P9 pin orientation before energizing.
Preserve provenance, original labels, jumpers and test conditions. Photograph the board before repair; avoid aggressive cleaning or desoldering until corrosion and component risks are documented.
Manufacturer and archive manuals
- Chaintech 4SPI scanned manual — The Retro WebDirect manual archive for memory, layout and setup details.
- Chaintech 4SPI board record — The Retro WebModel archive with board identification and supporting documentation.
Archived copies may cover another board revision. Compare manual diagrams and revision identifiers with the physical PCB; do not flash firmware or set voltage jumpers from a related model's manual.