KIM-1 is a small single-board computer based on MOS 6502 microprocessor released by MOS Technology company in 1976. It is considered one of the earliest single-board computers and achieved great success in the 1970s.

KIM-1 consists of two 6530 chips together providing 2K bytes of ROM (Monitor program, 1K bytes per chip), 128 bytes of RAM (64 bytes per chip), and four 8-bit bidirectional IO Ports (two per chip) and two programmable clocks/timers (one per chip). The RAM of KIM-1 is usually called 1K byte capacity, but to be precise, the RAM space it can provide is 1152 bytes (8 1K bits RAM + 128 bytes RAM in two 6530); A 23-key hexadecimal keyboard is used for program and instruction input, and 6 seven-segment LED displays can completely display the address information and data information of the 6502 CPU; KIM-1 also provides the connection capability of the TTY terminal and tapecorder to store and load programs.

PAL-2's difference

First, PAL-2 is a kit, you can assemble it, test it and run it all by yourself —— an unique experience！

The PAL-2 addressing mode is completely implemented in accordance with the design of KIM-1, so it is compatible with most programs developed on KIM-1.

PAL-2 has 2K bytes ROM (complete KIM-1 Monitor), 65K bytes RAM, two 6532 RIOT chip on board, provides a full KIM-1 experience except the audio part. In addition, PAL-2 also provides TTL serial port to support terminal operation and KIM-1 compatible expansion ports for future upgrade.

The PAL-2 is essentially a PAL-1 SBC integrated with 32K RAM and a second RIOT on a single PCB, providing you with a more complete and convenient KIM-1 experience. Additionally, the PAL-2 has redesigned the layout of the LED and keyboard areas to more closely resemble the original KIM-1 structure. Beyond upgrading the keyboard design, all micro switches used in the PAL-2 are sourced from Omron or Diptronics, significantly improving reliability, stability, and ease of use compared to the PAL-1.

In addition to high-quality micro switches from top-tier manufacturers, all major components of the PAL-2 are sourced from leading brands, from the PCB to resistors, ensuring an upgraded assembly and usage experience. Even if you choose to display it in a picture frame, it would still be a great option!

Improvements have also been made in areas that aren’t immediately visible. Compared to the PAL-1, the PAL-2 PCB uses Taiwan-made Nanya TG135 material, lead-free HASL, high-definition silkscreen printing, protective paper packaging, and other high-quality enhancements.

What is included

The PAL-2 Kit includes mainboard PCB, ICs, pre-programmed EEPROM, passive components, sockets & headers.

Print version BOM, Schematic and Parts layout.

A USB-to-TTL converter (USB-C)

What is NOT included

You need a USB-C data cable compatible with your current computer, USB 2.0 version is sufficient.

Some jumper wires.

Users Group

For building, debugging, communication with other PAL-1/2 users - Google Groups

Document

User Manual (en)

Schematic

Interactive BOM

Recommend site

Nils' load and go repository

Jim's Repository

Hans' knowledge base