Homebrew 8088

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28C256 32k EEPROM Writer 

Raspberry PI PCB

email:   info@homebrew8088.com

Introduction:

    This web page is dedicated to my 8088 Motherboard project. The Motherboard is built to be generally PC XT compatible. The schematics and source code can be found on my GitHub page. 

Features:

-8088, NEC V20, or NEC V40 Processor

-640k RAM (This can be changed)

-8 Bit ISA sockets

-PC Speaker

-USB "Hard Drive"

-PS/2 Keyboard

-ATX form factor

Discussion:

Join the discussion group on Discord 

https://discord.gg/AswNqwpRGP 

Resources:

These resources are intended to be helpful if your trying to build an 8088 project of your own. 

The schematics and BIOS files can be found on GitHub

https://github.com/homebrew8088/8088-PC-XT-Compatible 

YouTube Channel (Demos and other Information)

EMM Computers Play List 

Project More Defined:

Main Board:

Features:  

-ATX Form Factor 

-ATX Power Connector

-8284 with 14.31818 Crystal

-PC Speaker

-PS/2 Keyboard connector

Port Map:

-Port 0x00, 8237 DMA Controller 

-Port 0x60, 8242 PS/2 Keyboard Controller 

-Port 0x61

Bit 0 = Speaker GO

Bit 1 = Speaker Enable

Bit 5 = NMI Enable

-Port 0x80, DMA Index Register

-Port 0xE0, USB Port

2x8 Card Expansion Slot Pinout:

               IRQ1 -]   [- Reset Active Low

IO CS 0x000_ -]   [- Ready to 8284 input

IO CS 0x002_ -]   [- Hold

IO CS 0x004_ -]   [- HoldA

IO CS 0x006_ -]   [- DRQ0

IO CS 0x008_ -]   [- Half PCLK

                 NC -]   [- Speaker GO

               NMI -]   [- Speaker Out 

8088 / V20 Processor Card:

Features:  

-8088 or V20 Processor 

-8259 Programable Interrupt Controller

-8253 or 8254 Programable Interval Timer 

-8284 Clock Generator 

V40 Processor Card:

Features:  

-V40 Processor (70208)

V40 Processor Card With 640K Ram, 64K Rom:

Features:  

-V40 Processor (70208)

-AS6C4008 512k RAM

-AS6C1008 128k RAM

-64K ROM Any Pin Compatible with W29C020 chip 

-Extra Socket 64K Address 0xE0000 

640K Ram, 64K Rom Card:

Features:  

-AS6C4008 512k RAM

-AS6C1008 128k RAM

-64K ROM Any Pin Compatible With W29C020 chip 

-Extra Socket 64K Address 0xE0000  (Pictured DiskOnChip Installed)

640K Ram, 32K Rom Card:

Features:  

-AS6C4008 512k RAM

-AS6C1008 128k RAM

-32K ROM Any Pin Compatible With AT28C256 chip 

-Extra Socket 32K Address 0xF0000  (Pictured 32k RAM Installed)

CH376 USB Host Card:

Features:  

-CH376

Older PCB's:

Main Board (Still in use but phasing out for built in DMA controller Main Board) 

 DMA Card (Still in use but phasing out for built in DMA controller) 

512K Ram / 32K Rom (Not Made Anymore)