VMIC VMIVME-7486 Single Board Computer

Module Feature

VMIC VMIVME-7486 is a single-slot 6U VMEbus single board computer built around Intel 80486 series processor, available in 25 MHz SX,33 MHz DX or 66 MHz DX2 versions, equipped with 8 KB four-way set associative on-chip cache. It supports up to 16 MB 32-bit DRAM, onboard 1 MB video DRAM for SVGA display, maximum resolution 1024×768 non-interlaced. Integrated peripheral set includes two independent RS-232C serial ports, one Centronics parallel port, PC/AT keyboard interface and battery-backed real-time clock. Storage controllers support floppy disk and IDE hard disk via P2 rear I/O connector. Custom gate array implements complete VMEbus master/slave function, supports A16/A24/A32 addressing and D16/D32 data transfer. Three-way hardware byte swap circuit enables seamless data exchange between little-endian PC architecture and big-endian VME modules. The board can run DOS, early Windows and VxWorks real-time OS. Rugged Eurocard construction, widely deployed in legacy turbine control, data acquisition, industrial HMI and aerospace test VME chassis.

Working principle

Intel 80486 CPU executes PC/AT compatible operating system and application code. Custom VME gate array provides full VME bus master and slave capability, allowing the CPU to access memory and registers of other VME boards. Hardware byte-swap logic automatically adjusts data order during VME read/write transactions to eliminate software conversion overhead. SVGA graphics controller generates video output for front panel monitor connector. Dual UART chips handle RS232 serial communication; parallel port supports printer and peripheral connection. Battery-backed RTC maintains system time after power loss. Floppy and IDE controllers connect storage devices through rear P2 connector. VME interrupt handler responds to interrupt signals from other VME modules.

Onboard components

Intel 80486 CPU, 8 KB on-chip cache, 32-bit DRAM socket, SVGA graphics chip with 1 MB video DRAM, dual RS232 UART, Centronics parallel port, floppy & IDE controller, battery-backed RTC, custom VME gate array, three-way byte swap logic, VME J1/J2 transceivers, front panel SVGA, COM and keyboard connectors, status LED array, manual reset pushbutton.

LED indicators

Front panel LED indicators for board +5 V power, CPU status, VME SYSFAIL fault and bus activity alarm.

Hardware self-diagnosis

Visual inspection of PCB, front ejectors and solder joints; board ID register readback verification; POST power-on self-test; memory read/write cyclic verification; SVGA display test; serial and parallel port loopback test; VME A16/A24/A32 read/write communication test.

Programming software

VMIC BIOS configuration utility, supports DOS, Windows 3.x, VxWorks, QNX real-time operating systems; universal VME driver library for register access and interrupt handling.

Electrical & Process Parameters

Model: VMIVME-7486 Device type: 6U VMEbus PC/AT compatible single board computer Bus standard: VMEbus, A16/A24/A32 addressing, D16/D32 transfer Processor: Intel 80486 SX / DX / DX2 (25 /33 /66 MHz) Memory: Max 16 MB 32-bit DRAM, 1 MB video DRAM Graphics: SVGA, up to 1024 ×768 non-interlaced Interfaces: 2 × RS232C, 1 × Centronics parallel, PC/AT keyboard, IDE / floppy Control mode: VME master / slave operation, hardware three-way byte swap Power supply: +5 V from VME backplane Cooling: Convection cooling Protection: Over current, ESD protection, VME bus error detection Mounting: Standard 6U VME front panel ejector locking Protection class: PCB with optional conformal coating

Mechanical & Structure

Mounting: Standard single-slot 6U VME Eurocard Protection class: PCB with optional conformal coating

Environmental

Operating temperature: 0℃ ~ +60℃ Storage temperature: -40℃ ~ +85℃ Ambient humidity: 5~95% non-condensing Certification: CE compliant Status: VMIC legacy 486 PC/AT VME single board computer

Installation

Follow ESD safety procedure before handling. Fully power off VME chassis. Insert VMIVME-7486 into vacant 6U VME slot and lock front panel ejector latches. Connect front panel SVGA, serial port and PC/AT keyboard peripherals. Wire floppy and IDE storage devices to rear P2 connector. Power on chassis and enter BIOS to configure memory and boot sequence. Install OS and VME driver, run POST and full peripheral diagnostic before commissioning.

Interface

VME J1/J2 backplane connector, front panel SVGA video, dual RS232 COM ports, PC/AT keyboard port, IDE/floppy storage via P2 rear I/O, fault status signal pins.

Diagnostic

Board fails POST: faulty DRAM memory, defective CPU chip, abnormal backplane power. VME data misalignment: byte swap register misconfiguration. Serial port communication failure: baud rate mismatch or UART chip damage. RTC time loss: backup battery depletion. SVGA no display: video DRAM fault or monitor wiring error.

Product Brief

VMIVME-7486 VMIC single height 6U VME single board computer,Intel 80486 processor and full PC/AT compatibility,with SVGA,dual RS232 and hardware byte swap,for legacy industrial control,data acquisition and HMI VME chassis systems.