AppleII-VGA markadev

Toysoft·AppleII-VGA_markadev·AppleVGA/AppleVGA.kicad_pcb

About the AppleII-VGA markadev PCB

AppleII-VGA markadev is an open source RP2040/RP2350 PCB design by Toysoft, published on GitHub under the MIT license. It is a 2-layer board measuring 172.7 × 69.1 mm, with 33 components from 16 distinct parts.

Its main chip is the Pico, from the RP2040/RP2350 family. Other key parts include the 74LVC245, 74LS07 and UA78M33CKCS. By type, the board carries 17 resistors, 6 ICs, 6 capacitors, 2 connectors, 1 switch and 1 diode.

It belongs with the displays & leds designs in this gallery.

From the project

https://github.com/markadev/AppleII-VGA

This project is a VGA card for Apple II computers to ouput a crisp RGB signal to a VGA monitor instead of having to rely on the composite output. This is accomplished by snooping the 6502 bus and creating a shadow copy of the video memory within a Raspberry Pi Pico, then processing the raw video memory contents to output a "perfect" signal.

+------+ +-----+ +-----------+ | 6502 |_____________| RAM || Composite | | CPU | System \ +-----+ | Video Gen | +------+ Bus | +-----------+ | +-----------+ \| Raspberry |______________\ | Pi Pico | 640x480 VGA / +-----------+

AppleII-VGA markadev, from the project README — From the project README

Main components on the AppleII-VGA markadev

74LVC245 74LS07 UA78M33CKCS Pico

AppleII-VGA markadev bill of materials (BOM)

33 components, 16 distinct parts — part numbers from the project's BOM.

Qty	Part	Footprint	Refs
3	74LVC245	DIP-20_W7.62mm_Socket	U1, U2, U3
1	74LS07	DIP-14_W7.62mm_Socket	U4
1	UA78M33CKCS	TO-220-3_Horizontal_TabDown	U5
1	Pico	RPi_Pico_SMD_TH	U6
1	AppleIIBus	AppleIIBus_Edge	J1
1	VGA	PinHeader_1x08_P2.54mm_Vertical	J2
1	SW_Push	SW_PUSH_6mm_H5mm	SW1
1	D_Schottky	D_DO-41_SOD81_P10.16mm_Horizontal	D1
5	0.1uF	C_Disc_D4.3mm_W1.9mm_P5.00mm	C1, C3, C4, C5, C6
1	0.33uF	C_Disc_D4.3mm_W1.9mm_P5.00mm	C2
3	330	R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal	R1, R2, R3
3	500	R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal	R4, R7, R10
3	1K	R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal	R5, R8, R11
3	2K	R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal	R6, R9, R12
2	47	R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal	R13, R14
3	10K	R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal	R15, R16, R17

AppleII-VGA markadev design files

The KiCad project lives in the Toysoft/AppleII-VGA_markadev repository on GitHub; these links point at the commit this page was built from.

AppleII-VGA markadev: common questions

What microcontroller does the AppleII-VGA markadev use?

The AppleII-VGA markadev is built around the Pico, from the RP2040/RP2350 family.

How big is the AppleII-VGA markadev PCB?

The AppleII-VGA markadev measures 172.7 × 69.1 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the AppleII-VGA markadev?

33 components, from 16 distinct parts, with part numbers taken from the project's own BOM. The full bill of materials is listed on this page.

Where can I download the AppleII-VGA markadev design files?

From the Toysoft/AppleII-VGA_markadev repository on GitHub, which has the KiCad layout, the schematic and the BOM; the links under Design files point to each one.

Can I use the AppleII-VGA markadev design in my own project?

Yes, under the terms of its MIT license, which Toysoft chose for the repository.

Can I test firmware for the AppleII-VGA markadev without the hardware?

Yes. HardLabs builds a simulation of the board from its netlist and BOM, so you can run and debug RP2040/RP2350 firmware against it before you order a PCB.