4 layers56.1 × 57.1 mm
MCL86jr
MicroCoreLabs/Projects
Ted Fried's MicroCore Labs Projects - FPGA CPU cores and emulators for the 8088, 8086, 8051, 6502, 68000, Z80, Risc-V, and also Typewriter and EPROM Emulator projects.
66 parts534
4 layers81 × 46 mm
XTMAX PCB
MicroCoreLabs/Projects534Ted Fried's MicroCore Labs Projects - FPGA CPU cores and emulators for the 8088, 8086, 8051, 6502, 68000, Z80, Risc-V, and also Typewriter and EPROM Emulator projects. MCL51, MCL64, MCL65, MCL65+, MCL68, MCL86, MCL86+, MCL86jr, MCLR5, MCLZ8, MCL6809, XTMax, MCL8080+
- Size
- 81 × 46 mm
- Copper layers
- 4
- Thickness
- 4.69 mm
- Parts
- 14
- Nets
- 108
- Pads
- 302
- Tracks, vias
- 889, 166
- Pours
- 4
- Routed
- Yes
- KiCad
- KiCad 6 (file 20211014)
- Created
- 11 Aug 2019
- Updated
- 28 Aug 2026
Overview
XTMAX PCB is an open-source printed circuit board by MicroCoreLabs, from the MicroCoreLabs/Projects repository on GitHub. It is a 4-layer board of 81 × 46 mm with 14 parts on 108 nets, routed with 889 tracks and 166 vias.
It is built around the SN74LVC244AN, TEENSY 4.1 and SN74LVC245AN. Its parts include 7 ICs, 4 capacitors and 3 connectors. It belongs with the retro computing and games boards and the NXP (LPC, Kinetis, i.MX RT) boards of this library.
Main components
3
SN74LVC244AN
PDIP-20-40℃~+125℃ 1.65V~3.6V 2 24mA 24mA 3.9ns@3.3V,50pF 4 40uA 74LVC Tri-State Unidirectional PDIP-20 Buffers, Drivers, Receivers, Transceivers ROHSTexas InstrumentsBuffers, Drivers, Receivers, Transceivers
TEENSY 4.1
Development Boards & Kits - ARM ModuleSparkFun ElectronicsUncategorisedSN74LVC245AN
DIP-20UncategorisedTexas Instruments
README
README.mdTed Fried's MicroCore Labs Projects
My blog which has some details on these projects: www.MicroCoreLabs.Wordpress.com
My YouTube Channel with some videos of the stuff in action: www.youtube.com/channel/UC9B3TaEUon-araO2j7tp9jg/videos
Boards:
MCL6809 - Motorola 6809E emulator which runs on a Teensy 4.1 and can be used as a drop-in replacment
MCLZ8 - Zilog Z80 emulator which runs on a Teensy 4.1 and can be used as a drop-in replacment
MCL86+ - Intel 8088 emulator which runs on a Teensy 4.1 and can be used as a drop-in replacment
MCL86jr - IBMPCjr Accelerator which boosts performance to IBM PC/AT speed
MCL65+ - MOS 6502 emulator which runs on a Teensy 4.1 and can be used as a 6502 drop-in replacment
MCL64 - MOS 6510 emulator which runs on a Teensy 4.1 and can be used as a drop-in replacment in the Commodore 64
MCL68+ - Motorola 68000 emulator which runs on a Teensy 4.1 and can be used as a drop-in replacment
MCLV20_Max - NEC V20 drop-in replacment CPU which uses the MCL86+ board
MCL8080+ - Intel 8080 emulator which runs on an ATTiny85 and has a SPI interface as the local busEmulated Processors:
MCL68 - Motorola 68000 Emulator written in C
RISCV - Simple and compact RISC-V RS32I implementation written in C
MCL65 - MOS 6502 written in CMicrosequencer-based processors:
MCL65 - MOS 6502
MCL51 - Intel 8051
MCL86 - Intel 8086/8088Other processors:
MCLR5 - Quad-Issue Superscalar RISCV
Lockstep Quad Modular Redundant System Misc:
Wheelwriter - FPGA based Printer Option for the IBM Wheelwriter 5
Wheelwriter2 - Arduino Leonardo based Printer Option for the IBM Wheelwriter 5
Brother Typewriter - Arduino Leonardo converts Serial RX to a Brother Word Processor
EPROM Emulator - Small PCB which uses Teensy 4.0 to emulate up a 64KB 27C512 EPROM
MCL64_Tester - Extensive, menu-based, tests for the Commodore 64 motherboard
MCLZ8 TRS-80 Emulator - Emulates a TRS-80 Model 1 inside of a Teensy microcontroller board
MCL_TRS_NABU - Emulates a TRS-80 Model 1 using the MCLZ8 which runs inside of a NABU Personal Computer
Turbo NABU - Uses the MCLZ8 to run simple C code on the Teensy to control the motherboard resources of the NABU Computer
MDA Video - Project which uses an Arty Z7-20 SOC FPGA board to diaplay BMP images to an MDA display
IBMPC_68000 - Uses the MCL86+ board to emulate a Motorola 68000 which runs inside of an IBM PC as-if they selected this processor in 1981
MCL65_Apple1 - Converts an Apple II into an Appke 1 by emulating the BIOS PROMs, system memory, and performing some I/O conversion
XTMax - 8-bit ISA card containing a Teensy 4.1 which can emulate RAM, ROM, and peripherals
For questions email me at www.MicroCoreLabs.com
Parts
14| Qty | Value | Footprint | References |
|---|---|---|---|
| 5 | SN74LVC245A | Package_SO:TSSOP-20_4.4x6.5mm_P0.65mm | U1, U3, U4, U7, U8 |
| 4 | 10 uF | Capacitor_SMD:C_0402_1005Metric | C1, C2, C3, C4 |
| 1 | Bus_ISA_8bit | isa_ted:isa | J1 |
| 1 | Conn_02x01 | Connector_PinHeader_2.54mm:PinHeader_2x01_P2.54mm_Vertical | J3 |
| 1 | Conn_02x31_Odd_Even | Connector_PinHeader_2.54mm:PinHeader_2x31_P2.54mm_Vertical | J2 |
| 1 | SN74LVC244 | Package_SO:TSSOP-20_4.4x6.5mm_P0.65mm | U5 |
| 1 | Teensy4.1 | Teensy:Teensy41_Ted_Modified | U2 |
Questions
How big is the XTMAX PCB PCB?
It measures 81 × 46 mm and has 4 copper layers, 4.69 mm thick.
What parts does the XTMAX PCB use?
14 parts, built around the SN74LVC244AN, TEENSY 4.1 and SN74LVC245AN. 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 XTMAX PCB KiCad files?
From the MicroCoreLabs/Projects repository on GitHub, at the commit this page was made from: the board is XTMax/PCB/XTMAX_PCB/XTMAX_PCB.kicad_pcb and its schematic MCL68+/PCB/MCL68.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the XTMAX PCB design in my own project?
Its repository states no licence, so its author keeps all rights: ask MicroCoreLabs before reusing the design.
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