COMMODORE VIC-20 SD2iEC + 35KB (27+8) RAM EXPANSION CARTRIDGE

Hello,

This is a tested and working project. (Tested on a NTSC Commodore VIC-20 plugged to a C64 PSU)

COMMODORE VIC-20 SD2iEC + 35KB (27+8) RAM Expansion Cartridge is an Easy DIY project, all components are through hole, marked on the PCB, Easy to solder, Easy to make ;)

This PCB is a combination of two independent projects, one of them is SD2iEC (Commodore disk drive emulator) and the other is Commodore VIC-20 35KB (27+8) RAM Expansion Cartridge. They can be used separately or both together.

This, "Commodore VIC-20 SD2iEC + 35KB (27+8) RAM Expansion Cartridge" PCB is also available for SMD ATMEGA644P and ATMEGA1284 in TQFP package, you may prefer to use either DIP or TQFP package. DIP package is easier to program and easier to solder, but TQFP package AT644P or AT1284 are usualy cheaper and easy to find than DIP package models.

More information about Commodore VIC-20 35KB (27+8) RAM Expansion Cartridge:

https://www.pcbway.com/project/shareproject/COMMODORE_VIC_20_35KB_27_8_RAM_EXPANSION_CARTRIDGE_a2f375ab.html

More information about SD2iEC (Commodore disk drive emulator):

https://www.pcbway.com/project/shareproject/SD2iEC_COMMODORE_64_DISK_DRIVE_EMULATOR_POWERED_from_USER_PORT_MICRO_SD_VERSI_c56a9f83.html

Many thanks Ruud Baltissen from Netherlands for VIC-20 35KB (27+8) RAM Expansion Schematics.

Please choose "Edge connector YES and Bevelling Yes (45°)

COMPONENTS for RAM EXPANSION part:

62256 DIP28 (32KB STATIC RAM)

6264 DIP28 (8KB STATIC RAM) (You can use 62256 or 4364)

74LS21 DIP14

2PCS. DIP28 WIDE IC SOCKET

DIP14 IC SOCKET

8P DIP SWITCH (You can use 2x8 Pin 2.54mm pitch male header and 8pcs. jumper caps)

8 PCS. 1/4 WATT 10K OHM RESISTOR

3 PCS. 100nF CERAMIC CAPACITOR

220 μF 16V ELECTROLYTIC CAPACITOR

RIGHT ANGLE TACTILE BUTTON (For RESET Button)

COMPONENTS for SD2iEC part:

6 pin Micro SD Card Module (will be placed to the bottom side)

3mm RED LED

3mm BLUE LED

2 PCS. 470ohm - 1K 1/4watt RESISTANCE (value changes leds brigtness)

10K 1/4watt RESISTANCE

8 Mhz Passive Quartz Crystal

1N4148 DIODE

2 PCS. 22pf or 33pf ceramic CAPACITORS

100nF ceramic CAPACITOR

6pin MALE DIN CONNECTOR

6PIN MALE HEADER

1PCS. HEADER JUMPER CAP

3 PCS. RIGHT ANGLE TACTILE BUTTON

6 PCS. 30cm MALE-FEMALE DUPONT CABLE

Micro SD CARD (4GB will be enough)

2 PCS. 2PIN MALE HEADER

ATMEGA1284 or ATMEGA644 (DIP40 or TQFP)

DIP40 WIDE IC SOCKET (if prefered to use ATMega DIP40 )

You will need a programmer for ATMEGA

If you have a programmer capable of testing IC chips, such as the 74LS series and static RAM chips, you should remember to test them before soldering. Some chips may be defective. (TL866 Minipro Programmer can test some logic ICs and static RAM chips)

In order to protect your electronical devices, always turn off your Commodore before connecting or disconnecting the cables or any other device.

** If you want to use SD2iEC not inserted to the VIC-20 cartridge port then you need to provide DC +5V power to the PCB. (DO NOT CONNECT EXTERNAL POWER SOURCE TO THIS PCB WHILE IT IS INSERTED TO COMMODORE VIC-20! )

While transfering data (reading or writing) from SD cards it should not be interrupted like power-off or Reset systems. Otherwise that may damage SD cards.

Gerber files can be changed at any time. Before paying for the PCBs, be sure to update your orders!

As you can see I have uploaded many projects and I am still working on new projects. If you have any questions, please look for answers online. Unless I specify explicitly, all my projects are tested and confirmed to work under normal circumstances before being shared. I'm sorry I didn't have enough time to answer all the questions.

Use this PCB at your own risk !

Have fun

Thank you.