An 8088 computer.

This is a single board Intel 8088-based computer. It features 32k of SRAM and 32k of EEPROM (UV EPROM works as well). There’s an 8255 for parallel I/O, currently driving a Hitachi style 4 line by 20 character LCD. An 8259A interrupt controller. A 82450 UART salvaged form old serial card for serial I/O. Currently the program reads the serial input and displays it on the LCD and echos it to the serial output – UART generates interrupt on byte received and computer reads it in. An 8253 timer is currently being used to generate 100 interrupts per second to count time since power on. All software is written in assembly, assembled with nasm, then written to EEPROM. It doesn’t run an OS, just programs to demonstrate the hardware.

Initial design, which contains microprocessor, clock, bus driver and control signal decode, based on Helm PCB 8088 found here.

Assembly

Nasm was used to assemble the programs. It runs on Linux, Windows, and Mac OSX.

To assemble the program contained in test.asm, execute:

nasm -f bin -o test.bin test.asm

test.bin contains the assembled program and may be written directly to ROM.