80186 Enthusiast
Experienced Member
- Joined
- May 18, 2023
- Messages
- 53
(WARNING: LOST OF TEXT AND IMAGES)
In my previous post, I learned that if I wanted to make a 16-Bit 80186 CPU Computer, I would've needed 16 bit wide memory and use the HBE pin. So I decided to make a 80188 Prototyping system before making a 16-Bit system. I'll also go over the details of this project in depth in this post.
Why start with an 8-Bit system? Simple! so I can develop the essentials for this project! The 80188 ended up being easier for me to wrap my head around.
Here are some of the details of this current project:
Name: Sea Otter I188 Environment Prototyping System
RAM: AS6C4008-55PCN (512k SRAM)
ROM: Windbond W27C512-45Z (64k EPROM)
CPU: 80c188
I won't be creating an address decoder that's capable of bank switching until I require it in later prototype designs and I learn more about Bank Switching.
This design is intended to connect jumper wires to a breadboard that has the Hardware that I'll be testing with to add to the next Prototype revision. I've based the CPU side of the schematic off of Slador's YouTube Tutorials and Official Intel documentation. For my system, I'll be using the Multi-Master Bus to Interface to several Bus Masters such as a 8279 Keyboard Controller, a Raspberry Pi Pico for VGA video Output, and a 8255 PPI to read and write data from an SD Card to be used for a cartridge slot and for SNES controller slots.
Here is the schematic and PCB design (with no ground planes so all of the traces are visible) I've made for this project (I'll provide higher quality images in a reply to this post):
As I stated, this board is used for testing the Multi-Master Bus and interfacing to hardware on a breadboard.
Why use a Raspberry Pi Pico for VGA Video? So I can program a Video Controller that's more or less exactly what I need for this project!
If any of you guys see any errors I've made in the schematic or PCB design, please tell me.
As for the future of this project. After creating a PCB that has all of the hardware that I've tested with and having an Address Decoder that's actually good, I'll build a finalized 8-Bit System. As for the OS for this machine, that's something a Friend and I are making together. the OS is called SOOS (Sea Otter Operating System) and that will be inspired by MS-DOS and Early Versions of Windows. I'll make mock-ups of what the OS will look like soon. I Do not plan on adding a Mouse to this Computer because It'll be a headache trying to find a PS/2 Controller IC that supports Mouses and then coding for that, Unless I can use a Raspberry Pi Pico to make that easier, but even then, that's more coding I don't want to go through. SOOS will be controlled only by the Keyboard and SNES controllers as I'll make it extremally easy to interface with, without a mouse. for future 16-Bit prototypes, I may experiment with adding a Mouse due to having a wider Data Bus and overall better capabilities.
as for the address Decoder, I'll make it more and more complex as I make more and more complex designs that have other Bus-Masters on the Multi-Master Bus. Only an LCD screen and the Memory Chips will be on the CPU local Data and Address Bus.
That's it for this post detailing this project, I'll defiantly create more posts about this project as I continue to keep working on it!
Your feedback and advice will be thanked in advanced! Thank you for reading my post here!