I have several KIM-1 replica’s or clones, and there are more available.

For me a KIM-1 Replica/clone needs a KIM-1 keypad and LED dispaly, a serial TTY interface, and the original KIM-1 software. Some have a layout close to the KIM-1, others look different, but all are functionally equivalent.

The CPU is of course a 6502 at 1 MHz crystal clock frequency. And they have at least the KIM-1 ROM 6530-002, the keypad/LED/TTY monitor.

Since 6530 RRIOT ICs (the 002 and 003 variant) are not available anymore, the same solution as in the other clones is chosen: a 6532 RIOT with a 2K EEPROM and some logic ICs (3) to get a hardware solution that makes it look exactly the same for the KIM-1 ROM software. The PCB is mostly a new design, not the typical 70ties KIM-1 rounded lines PCB design (except the KIM-1 Nachbau and the accurate reproduction by Eduardo Casino).

All this started with a design by Ruud Baltissen, who found out how the 6530 can be replaced with a 6532.

The result is great: it feels, looks and operates as an original KIM-1 with hex keyboard and LED display and TTY serial interface.
First Book of KIM programs run, All KIM-1 software runs, Microsoft KIM-1 Basic and Microchess run, when additional RAM is connected.

• KIM-1 rev D PCB redesign Eduardo Casino
• RC-ONE a KIM-1 clone
• Replace both 6530s in KIM-1
• Ruud Baltissen: Build a KIM-1
• Wozmon in the KIM-1 clone
• Nachbau eines KIM-1
• Micro-KIM
• PAL-1
• Corsham Technologies KIM Clone
• MOS KIM-1 Reproduction
• KIM-1 Nachbau
• KIM-1 Replika
• KIM Uno

Corsham KIM Clone	MOS KIM reproduction
KIM Uno	Micro-KIM
PAL-1 a clone, can be expanded with motherboard, second RIOT, RAM, ROM, Cassette interface	Nachbau KIM-1

KIM-1 Reproduction by Eduardo Casino

KIM-1 MTU baords by Eduardo Casino

Photos by Peter Offterdinger of ralf02 KIM clones and MTU backplane and K-1013 Visable Memory

MTU backplane and K-1013 Visable Memory display designed by Eduardo Casino

Optional add-ons to make the Micro-KIM a real KIM-1, with the second 6530/32 and a 32K RAM card to give enough RAM to run real programs like KB9 Basic.

The expansion connector is made for this. With the expansion board up to four cards can be added.

A 40 pins male connector. Pin 1 is labeled on the board and is near the edge at the upper-left corner
of the connector.

Here he description of the expansion connector. Also see the Circuit diagram.

32K RAM

Circuit diagram of memory expansion

Second EPROM
The Micro-KIM is already prepared for a second 6532. The ROM for it is in place, the address decoding is also available. This card brings the second 6532 with the free I/O and timers to connector.

The revision I have needs a wire to connect the missing ground line to the 74LS04 (tip from azog, Silent Q).

Expansion motherboard

With two expansion boards, both quite essential as shown above and one expansion connector, is not enough.
So the expansion board brings the expansion connector to four connectors, just one on one connected.
As you can see on the Cassette interface for the Micro-KIM page this makes for interesting additions.
The expansion board can be placed in two ways. The first way iverhanging the Micro-KIM for a compact solution. Or hanging outside, which makes attaching wires to expansion boards less risky. Always take care of the right orientation of the expansion boards, notice the ‘1’ on the baords and the exapnsion connector on the Micro-KIM.

The KIM Uno, designed and produced and sold by Oscar Vermeulen, is a very simple “open-source hardware” project that started out as a replica of the classic 1976 KIM-1 computer. Later, Apple-1 compatibility and a 6502 programmable calculator mode were added, plus a built-in ‘early 6502 software gems’ collection.
It costs about $10 in commonly available parts (board & parts without case or power supply), but provides a faithful KIM-1 ‘experience’. An Arduino Pro Mini mounted on the back contains all the logic and memory.

I have two versions: the ‘original’ and the later redesigned version, Software-wise the same, with on the top of the PCB room for power connector (GND, +5V or a 9V battery) and a slide switch. , I use them with an USB cable (the blue one of this page) for power and the serial interface provided.

The software already works on the blue pill STM32 or an ESP32, with manual cabling to the keyboard/display and I expect a new version of the PCB for the ESP32.

The software for the serial interface (you really need a good serial terminal emulator, like Minicom or Tera Term) can be used on any Arduino Uno. After power on  it delivers a simulation of the LED display or the real KIM TTY teletype interface (a bit broken in the current version).

All well described on the pages of Oscar and well worth the money for a ‘6502 SBC’ experience or a Cosmac 1802 with a small LCD.

The default serial output: an animated KIM display

Pressing control keys to perform ST and RS key

Press TAB to get into KIM TTY mode. Make sure to select on your terminal Local Echo and CAPS Lock. Read the KIM-1 User manual how the monitor operates.

The Apple 1 mode, fully functional.

Microchess adapted to serial

The Wozniak/Baum disassembler