6530 replacement board

Christer from Sweden built an Eduardo Casino designed KIM-1 replica. And as we know, the 6530 replacement is an issue.
Not only for replica’s also for broken original KIM-1s.

So he designed his own, more compact original looking adapter.
He created this adapter because I wanted something that would work and look a little more unobtrusive than the other adapter boards that are available but still look somewhat genuine (no FPGA). The design is inspired by the Corsham 6530 replacement board but made way smaller by using SMD components and stacking the 6532 on top of the adapter board.

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A newer design promised to be much more compact.

KIM KIM-1 which is what?

MOS Technology started development of the 6530 RRIOT very early after/during the 6501/2 development. All in 1975.

The first version of the Hardware Manual has this mention of KIM and TIM:

The KIM and TIM were mentioned as Keyboard and Teletype Input Monitor, indicating these are the 6530-002 and 6530-004 RRIOT IC’s. Indeed these ICs were sold later on.

The KIM-1 computer was developed later, with the KIM RRIOT and the 6530-003 audio cassette interfacing ROM using the KIM 6530-002 RAM and I/O ports.
The KIM-1 was not called -1 as first version, but for the 1K RAM included on the computer.
First shipping of the KIM-1 started in early 1976, then the first articles in the magazines and advertisements appeared.

So KIM is the 6530-002 RRIOT IC, KIM-1 is the computer around the KIM and 6530-003.

KIM-1 replica KIM-1000 with CHIPz modules, 6530 reDIP

Mark J Koch (https://github.com/CircuitMonkey/mos-kim1-replica, ‪@markjkoch.bsky.social) is designing a not so common KIM-1 replica, the KIM-1000,
with building blocks he calls ‬CHIPz modules.

He posted photos of his first versions, it is at this moment (October 2025) a work in progress.


As you can see on the photos the CHIPz modules on a ‘motherboard’ are recognizable KIM-1 blocks:
– application and expansion connector on motherboard, with ‘bus watchers’.
– keyboard and display, all KIM-1 keys, SST switch and the six LED displays. Standard KIM-1- (a 7442 instead of a 74145).
– CPU with 65C816, not the 65C02 one would expect here.
– Control logic, with clock, Reset and NMI, memory decode K0-K7, some glue logic for RAM R/W etc. Missing is the usual TTY and audio cassette glue logic. So no serial terminal!
– SRAM module 32K, mapped to all lower address except the KIM-1 holes 1400-1FFF
– 6530-002 and 6530-003 reDIPs

reDIP 6530

One of the building blocks will be the 6530/6532 redIP. More information on that 6530 replacement here.


The reDIP RIOT is an open source FPGA board which combines the following in a DIP-40 size package:

-Lattice iCE40UP5K FPGA
-1Mbit FLASH
-5V tolerant I/O
-The reDIP RIOT provides an open source hardware platform for 6530 RRIOT / MOS 6532 RIOT replacements.

All FPGA header I/O is 5V tolerant, and can drive 5V TTL.

KIM-1, were IC sockets used?

Before I saw the last revision, Rev G, I had never seen an original KIM-1 with IC sockets. All ICs were soldered right into the PCB.

Now I have a KIM-1 Rev G and a photo by Dick Dral of his KIM-1 Rev G with white IC sockets.


So the last iteration of the KIM-1 did have IC sockets.

Not only did Rev G come with sockets, they used not only white sockets, black ones too (Thanks Santo Nucifora).

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Images of the 6530s I have

Over the years I have acquired quite some 6530 ICs. Either as IC or built into a KIM-1, Jolt or Chessmate.

On this page I show these 6530s.

Note the timestamps: 1976 to 1982. MOS Technology, Synertek, Rockwell.


First Edition

Rev A

Rev B

Rev D

Rev E

Rev F Rockwell

Rev F

Rev G

Rev G

Digitus

3x Jolt

011 2x

024 3x

Chessmate

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6530 hardware emulator in FPGA in 40 pin DIP

Imagine a true 6530-002 and 6530-003 replacement , the RRIOTs of the KIM-1

Now with modern FPGAs you van do that: a 40 pin PDIP replacement: the reDIP RIOT is made for that purpose.

Here is the code for the reDIP to make it a 6530-002 or 6530-003:

Github with gateware for Commodore MOS 6530 RRIOT

Since the 6532 is in fact a subset of the 6530 (no ROM, more RAM), it seems not too difficult to make a 6532 replacement this way.

The reDIP RIOT is an open source FPGA board which combines the following in a DIP-40 size package:

Lattice iCE40UP5K FPGA
1Mbit FLASH
5V tolerant I/O
The reDIP RIOT provides an open source hardware platform for 6530 RRIOT / MOS 6532 RIOT replacements.

See here the github for this project

https://github.com/daglem/redip-riot

6530 hardware emulator in FPGA in 40 pin DIP

Imagine a true 6530-002 and 6530-003 replacement , the RRIOTs of the KIM-1

Now with modern FPGAs you van do that: a 40 pin PDIP replacement: the reDIP RIOT is made for that purpose.

Here is the code for the reDIP to make it a 6530-002 or 6530-003:

Github with gateware for Commodore MOS 6530 RRIOT

Since the 6532 is in fact a subset of the 6530 (no ROM, more RAM), it seems not too difficult to make a 6532 replacement this way.

The reDIP RIOT is an open source FPGA board which combines the following in a DIP-40 size package:

Lattice iCE40UP5K FPGA
1Mbit FLASH
5V tolerant I/O
The reDIP RIOT provides an open source hardware platform for 6530 RRIOT / MOS 6532 RIOT replacements.

See here the github for this project

https://github.com/daglem/redip-riot

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KIM Clone Rev 5

After almost a year (2019)of on-again, off-again, development we finally have a new revision of the KIM Clone.

It has everything the previous versions have, but with a few improvements people have asked for (or I wanted):

Expansion bus connectors! This was widely requested. Includes most processor signals, address and data buses, along with bank decoding lines. This is intended to plug into either a prototype board (more on this later) or a motherboard (in the works).
More jumpers to enable/disable blocks of RAM from being decoded. K1-K4 each have jumpers, and 8K blocks for the entire memory map have another set of jumpers. This allows blocks to be disabled on-board, then mapped to a user-supplied circuit.
Power on reset. Not a major feature, but I didn’t like having to press RS every time I turned on my KIM-1.
Power connector and the power switch moved to the top edge of the board.

KIM-1 Clone Rev 5 User manual
KIM-1 Clone Rev 5 User manual, other version

KIM Clone Rev 4

The first version that support expansion connectors.

KIM-1 Clone Rev 4 User manual

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KIM Clone Rev 3

Changes between Revision 2 and Revision 3 Boards

Revision 3 boards had a number of minor changes to fix know issues on Revision 2 boards. No new features or capabilities were added.
– IC19 was removed
–IC18 changed from 74AVC1T45 to 74LVC1T45
– IC16 changed to 74LS00
– IC7 and IC8 changed to 74LS145
– R37 and R38 changed to 470 ohms
– C18 was added
– IC17 had power routing fixed

KIM-1 Clone Rev 3 User manual