Tom80 - Z80 Based SBC

Several Versions of the Tom80 exist

Version 2.0B

Specs:

-See V2.0, differences listed here
-400k usable ram 8x48k banks and 16k fixed common memory, CPU sees 64k at all times but lower 48k can be swapped around

2B is the "definitive" version so all code going forward is designed for that version of the board.  
Minor hardware differences mean that code for 2.0 may not work on 2.0B without tweaks (mostly related to ram banking)

Video about 2.0B (and its Operating Systems): https://youtu.be/dH-JcmUzEUg

Version 2.0

Specs:

-Z80 CPU
-32K EEPROM (0x0000 - 0x7FFF), Can be disabled for full SRAM memory space
-64K SRAM (0x0000 - 0xFFFF)
-16550 UART Controller
-Counter Timer Chip (CTC) 
-Parallel I/O Chip (PIO)
-Parallax Propeller to allow for extra peripherals
	-SD Card
	-VGA 
	-PS/2 Keyboard
-5V Power Via USB (Z80 Only)
-Regulated power via wall jack (Z80 and Propeller)

V2 is 99% compatable with V1.X so most (if not all) code can be ported without much trouble
There are several (minor) known issues with V2 that will likely be fixed in a future revision

See a video about Version 2.0 here: https://youtu.be/p65Hw1WCuoc

Version 1.X

Specs:

-Z80 CPU
-32 Kilobytes EEPROM (0x0000 - 0x7FFF)
-32 Kilobytes SRAM (0x8000 - 0xFFFF)
-16550 UART Controller
-USB Serial Interface

A memory monitor (ASH.asm) can be assembled and run
Varoious flavors of basic can also be ported

See a video about Version 1.1 here: https://youtu.be/3KAjZbjPqnA

Prototype

Specs:

-Z80 CPU
-2 Kilobytes EEPROM (0x0000 - 0x07FF)
-2 Kilobytes SRAM (0x0800 - 0x0FFF)
-A single 8 bit latch for I/O

See a video of the prototype here: https://www.youtube.com/watch?v=QeUG9fH5Wn8

Was disassembled in late 2020, lives on only in pictures and videos

Other Stuff

Also Includes:

-Custom EEPROM Programmer Schematics
	-ATMEGA32A
	-28 Pin ZIF Socket
	-USB Interface

See a video about the programmer here: https://youtu.be/HartpD7Tr4I

Other (Older) files:

Arduino Micro EEPROM Programmer (Predecessor to Custom Programmer)
	-Arduino Code
	-Script to send data via Seral

Various Programs, mostly tests for EEPROM, SRAM, and I/O

TODO (As of 2021-10-9)

Tests for CTC are still lacking
Firmware for Propeller is not optimized
Schematics and manufacturing files for V2/V2B
Better documentation in general
Makefiles
Photos of 2B
Finish FUZIX port