

Z80vga
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)
- Size
- 135 × 100 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 53
- Nets
- 135
- Pads
- 373
- Tracks, vias
- 393, 80
- Pours
- 3
- Routed
- Yes
- KiCad
- KiCad 5 (file 20171130)
- Created
- 29 Mar 2020
- Updated
- 24 Nov 2023
Overview
Z80vga is an open-source printed circuit board by anjennings, from the anjennings/Tom80 repository on GitHub, published under the MIT licence. It is a 2-layer board of 135 × 100 mm with 53 parts on 135 nets, routed with 393 tracks and 80 vias.
It is built around the 74HCT273D and LP2985-33DBV. Its parts include 17 capacitors, 10 resistors, 10 ICs, 4 diodes and 4 connectors. It belongs with the FPGA and CPLD boards of this library.
Main components
274HCT273D
SOIC-20-300mil-40℃~+125℃ 12ns 3.5pF 30ns@4.5V,50pF 36MHz 3ns 4.5V~5.5V 4mA 5.2mA 74HCT Series 8 8uA D-Type Reset Rising Edge SOIC-20-300mil Flip Flops ROHSNexperiaFlip FlopsLP2985-33DBV
SOT-23-5-40℃~+125℃@(Tj) 1 150mA 16V 3.3V 30uVrms 45dB@(1kHz) 575mV@(150mA) 850uA Fixed Over Current Protection、Short Circuit Protection、Thermal shutdown、Enable control、Noise bypass terminal Positive SOT-23-5 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSTexas InstrumentsVoltage Regulators - Linear, Low Drop Out (LDO) Regulators
README
README.mdTom80 - 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 revisionSee 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 portedSee 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/OSee 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/OTODO (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 portParts
53| Qty | Value | Footprint | References |
|---|---|---|---|
| 8 | 22pf | Capacitor_SMD:C_1206_3216Metric | C2000, C2001, C2002, C2003, C2230, C2231, C3000, C3001 |
| 6 | R | Resistor_SMD:R_1206_3216Metric | R2000, R2001, R2002, R2004, R2005, R2006 |
| 4 | LED | LED_THT:LED_D3.0mm | D1001, D2000/M1, D2001/H1, D2002/ST1 |
| 4 | MountingHole | MountingHole:MountingHole_3.5mm | H0, H1, H2, H3 |
| 3 | 22pF | Capacitor_SMD:C_1206_3216Metric | C2110, C2120, C2121 |
| 3 | 4 x 10K | Resistor_SMD:R_Array_Convex_4x1206 | RN2000, RN2001, RN2230 |
| 1 | 1 uF | Capacitor_SMD:C_1206_3216Metric | C2232 |
| 1 | 10 nF | Capacitor_SMD:C_1206_3216Metric | C2234 |
| 1 | 100k | Resistor_SMD:R_1206_3216Metric | R2120 |
| 1 | 100nF | Capacitor_SMD:C_1206_3216Metric | C2113 |
| 1 | 10nF | Capacitor_SMD:C_1206_3216Metric | C2112 |
| 1 | 10uF | Capacitor_SMD:C_1206_3216Metric | C2111 |
| 1 | 14.7456 MHz | Oscillator:Oscillator_DIP-14 | U2003 |
| 1 | 1M | Resistor_SMD:R_1206_3216Metric | R2110 |
| 1 | 2.2 uF | Capacitor_SMD:C_1206_3216Metric | C2233 |
| 1 | 2.2K | Resistor_SMD:R_1206_3216Metric | R1000 |
| 1 | 2111 | Resistor_SMD:R_1206_3216Metric | R15 |
| 1 | 74HCT273 | Package_SO:SOIC-20W_7.5x12.8mm_P1.27mm | U2002 |
| 1 | 74LS07 | Package_SO:SOIC-14_3.9x8.7mm_P1.27mm | U2230 |
| 1 | AS6C8008-55_TSOP | Package_SO:TSOP-II-44_10.16x18.41mm_P0.8mm | U3001 |
| 1 | Conn_01x02_Male | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J2122 |
| 1 | Conn_02x08_Odd_Even | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | J2002 |
| 1 | GAL16V8 | Package_DIP:DIP-20_W7.62mm_Socket_LongPads | U2001 |
| 1 | LM555xM | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U2110 |
| 1 | LP2985-3.3 | Package_TO_SOT_SMD:SOT-23-5 | U2231 |
| 1 | MCP2221AxP | Package_SO:SOIC-14_3.9x8.7mm_P1.27mm | U2120 |
| 1 | Micro_SD_Card_Det | Connector_Card:microSD_HC_Molex_104031-0811 | J2230 |
| 1 | SST39SF040 | Package_DIP:DIP-32_W15.24mm_LongPads | U3000 |
| 1 | SW_Push | Button_Switch_THT:SW_PUSH_6mm | SW2110 |
| 1 | USB_B | Connector_USB:USB_B_OST_USB-B1HSxx_Horizontal | J2120 |
| 1 | Z8-L180-S180-180-PQFP-80 | UL_Z180:Z8018008FSG | U2000 |
Questions
How big is the Z80vga PCB?
It measures 135 × 100 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Z80vga use?
53 parts, built around the 74HCT273D and LP2985-33DBV. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Z80vga KiCad files?
From the anjennings/Tom80 repository on GitHub, at the commit this page was made from: the board is V3/kicad/z80vga.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the Z80vga design in my own project?
Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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