The KIM-1 turns 50 this year

[Neil Andretti]

But do we have an exact date?

On Hans site it says January 76.

We should celebrate it with a small demo.

I already have a MOS KIM-1 ascii logo and a starfield simulation (somewhere,  I have to search 😂...)

Anyone else want to join?

Happy new year everyone!

[Hans Otten]

January 1976 is the first date the KIM-1 was announced in magazines. So development started in 1975, shortly after the 6502 became available.

Real shipments came in the first quarter of 1976, with 6502 dates indicating it has no ROR instruction. 

So yes, 1976 is the year the KIM-1  started it now 50 years existence. And thanks to Eduardo new KIM-1s are being made.

[Hans Otten]

I date the birth of the KIM-1 to the date of the first KIM-1 User Manual, January 1976.  Very unlikely KIM-1s were sold before that date. 
Of course internal/external tests may have been done, but nothing is known about that.

Since magazines started writing about it in the first quarter, and the lead time of a magazine is minimal a month, it seems a safe guess.

Hans

[Neil Andretti]

here we go: who wants to join?

https://github.com/netzherpes/KIM1-Demo

nils 

[Ronny Ribeiro]

Oh my goodness 🤩 

That's lovely 😍 

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[Eduardo Casino]

Love your little demo, Nils :)

Sadly, creativity isn't one of my fortes, so I don't think I can contribute much.

Cheers,

Eduardo

[GN Liu]

Nils the best!

[Neil Andretti]

 1 step further.... the next version with another effect.

https://github.com/netzherpes/KIM1-Demo

The last thing I would like to add is a scrolltext at the shoutout screen on the LEDs 

[Neil Andretti]

Sorry for spamming: this is my final version. 

https://www.youtube.com/watch?v=aikJvjdEDto

The really ugly sourcefile is at https://github.com/netzherpes/KIM1-Demo 

share the message: 

🎉 HAPPY BIRTHDAY, KIM-1! 🎉 Wishing you — and all of us — a fantastic and hacky Year 2026 🥳✨

Nils 

[Voyageur]

Happy Birthday, KIM-1 !

To mark the 50th anniversary of the KIM-1, here is my modest hardware creation.

A modified replica, created for travel and easy to use. The acrylic case is supposed to protect the plate...

Board format 10 x 15 cm, 32 KB of RAM and/or ROM, an expansion connector for daughter-boards, a speaker and a white LED for debugging purpose. 

Time to connect a 5-volt power supply and ...

... the initial tests are proceeding without any problems.

It's far from perfect, but it replaces my precious PAL_1 computer for traveling and allows me to continue learning the machine language of the venerable 6502...

which is more difficult than using a soldering iron ! 

A+

[Hans Otten]

Fascinating! Great to see a KIM-1 in a compact design! Can you share some more details; like circuit diagram, contents of the 22V10? 

[Marco Rey y Sander]

And please show us the other side....with all the wires 😊

Gesendet von Outlook für Android

---

From: 'Hans Otten' via PAL 6502 computer <pal...@googlegroups.com>
Sent: Sunday, January 25, 2026 10:48:03 AM
To: PAL 6502 computer <pal...@googlegroups.com>
Subject: Re: The KIM-1 turns 50 this year

 

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[Ronny Ribeiro]

Marco was spot on! We would love to see the other side of the board!

Congratulations for the lovely design!

I posted here as a reply in other discussion topic some pictures of a 6502 computer I've put together. It started as a Ben Eater fac simile but I heavily modified and expanded it using a 22V10, 2 x 6522, 6551 and 65C02 @ 5MHz, all wire wrapped because I wanted so much to try this ancient sorcery 😂

Let me grab some pictures of it:

It runs eWoz, Microsoft Basic and BBC Basic, it's definitely not a KIM-1 replica but it shares some of its DNA 😂

Thanks for for sharing your lovely creation!

Happy birthday, KIM-1!

(By the way, I was born at right the same time 😂)

Very best regards to all KIM lovers,

Ronny

To view this discussion visit https://groups.google.com/d/msgid/pal6502/AM8P195MB09009AA19642B81E18A06390F492A%40AM8P195MB0900.EURP195.PROD.OUTLOOK.COM.

[Neil Andretti]

WOW! 

great idea! - So you use the PLD as ROM and address decoder? and in the FRAM the programs are persistant after power cycle?

Nils

[Hans Otten]

I suppose the FRAM serves as ROM and RAM. The 22V10 will map the FRAM to the right memory pages.

The 2981 is a buffer IC, with  he resistors, the 6532 RIOT and the 74145  and LED displays/keypad

A USB TTL circuit for TTY.  Battery power (regulated 5V) to make it portable.

And all this makes a very compact KIM-1 with a real 6502 and 6532! 

[Voyageur]

Thank you for your comments.

@ Hans : you have all good ! Bravo !

Some other explanations :

The original casing comes from a 'Schumann wave generator' sold on eBay as is.

I therefore decided to use this casing for my KIM1 travel project. It had to be cut down a bit to allow access to the keyboard.

. My version of Memory Map :     cf  the attached file 'MemoryMap.txt'

. the GAL manages all addresses between RAM, ROM and I/O  (from $0000 to $FFFF).

     cf the attached file 'KIM1mod.pld'

     and it's easy to change the addresses with WinCUPL and to adapt to any need...

. the FRAM RAMTRON FM1808 can keep out of power all the contents of the ROM and the RAM

     (here is a 32 KB capacity).

. the speaker is linked to PB7 of the RIOT 6532 (not used for Tape).

. the white LED is linked to PB6 of the RIOT 6532.

. the Monitor location (ROM as specified in KIM1mod.pld)  has the KIM1 6530-002 (I don't plan to use the TAPE storage) and the WozMon.

. the small USB TTL is a CH340E module, non expensive and easy to find a place on a board. I use a  USB C  retractable cable.

. the portable power supply is fit with a 5V Step-Up/Step-Down small module from Pololu and can accept four rechargeable or Alkaline  batteries.

. the KIM1mod's current is less than 175 mA

. the NE555 has the same function as half the 556 in the KIM1 circuit diagram (about the \NMI STOP switch).

. the 20 pin expansion connector accepts any daughter-board equipped with 65(C)22, 6821, 82C55, 6850, or ....

. the RESET circuit is a DS1813-10.

Here is the messy spaghetti dish on the other side of the board =

Please don't laugh at me. I could have been more organized, but the purpose was to make it easy for traveling... the layout of the circuits plays a significant role.

I tried to leave fairly long links made with wrapping wires. So it's less difficult to repair.  And you can see some of green links don't follow the rule....  

I focused on well soldered plots and at the end, I discovered only one mistake with my continuity tester : bad link at the PC/Keyboard switch.

I would like to share the circuit diagram but I am not good with schematics App. Could you tell me which one you use ?

 

A+

[Hans Otten]

Thank you Voyageur! That gives a very good impression of how it is build. 

Nearly all information to replicate it.  Only the 74LS00 , what does it do?

I guess you copied the KIM-1 LED display and keypad circuit, replacing the transistors with the 2981. 

I see the DS1813-10 on the left bottom side of the 65c02? 

And is there a transistor at the USB module?

Great idea to use the FM-1808 for permanent storage. It can be read and written by XGPRO!

A very popular and free PCB design program is Kicad. Available on Windows and Linux. Perfect to enter a schematic.

[Eduardo Casino]

Thanks, Voyageur! I love it, great old‑time DIY look, and there are some clever design decisions in there!

Even though KiCad isn’t particularly hard, it does have its learning curve. If you have anything hand‑drawn, even the wiring diagram you used, I can translate it into KiCad if you wish.

Eduardo.

[Ronny Ribeiro]

It's a great construction, Voyageur! You've color coded the connections and made them compact, perfect for a small design. I like the use of FRAM, I have some in here and I'm gonna give them a try in a breadboard.

I think Hans would publish your design. Accept Eduardo's kind offer and send him a hand drawing. You can learn kicad latter.

I think you have to show your creation off to a broad audience!

Regards,

Ronny

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[Voyageur]

Thanks again !

@ Hans

I used the 'PAL-1 USB Serial Mod', with a NPN transistor, a 74LS00 and some resistors.

I've downloaded and installed Kicad. It seems to be powerful and I will need some time to play with...

@ Ronny

I will do it. Time for me to redraw my diagram and make it more readable...

I use FRAM on some of the Single Board Computers that I've made and I like this technology.

@ Eduardo

I gladly accept your generous offer. If you can transform my diagram into a KiCad project, that would be great !

Do I post it here or send it to you ? 

A+

[Eduardo Casino]

@Voyageur, whatever you prefer, but I’m sure people here would love to see it too ;)

[Voyageur]

and here is attached the schematic. Hope it could be useful.

Regards

A+

[Hans Otten]

Thanks for the circuit diagram! Makes everything clear. 

I am now writing a page on my website about this.

One question. You wrote you have KIM ROM -002 and wozmon.  

How did you write that to the FM1808? EPROM programmer?

You have a binary?

All in all an awesome development!

[Eduardo Casino]

OK, first version. I still need to check a couple of details with @Voyageur, but I think it’s mostly OK. Comments are welcome :)

I’m in the middle of a project right now, but (with Voyageur's permission, of course) would there be any interest in a PCB?

On Tuesday, January 27, 2026 at 9:15:11 AM UTC+1 voyage...@gmail.com wrote:

[Voyageur]

Hi, 

To write to the FM1808, I use the TL 866-II Plus or the XGecu T48. Quick and easy...

I attached the complete dumb of the FM1808 in binary.

I just modified the 6530_002 in 'INIT1 :' value to transfer to PBDD

INIT1      ldx     #0
                stx     PADD            ; PA0..PA7 = input
                ldx     #$FF             ; was #$3F   PB0..PB5 = output,  B6 & PB7 = input
                stx     PBDD            ; now PB0..PB7 = output

                .....

so I can manage the speaker (PB7) and the white Led (PB6). 

And the white Led is off during normal use of the board, except for RESET or High level to PB6 added in my code.

The Woz Monitor comes from your website. The Start value is $1AA0.  (2400 or 4800 Bauds are OK for me).

There is plenty of free memory in RAM or ROM user.

Thank you, Hans 

A+

[Voyageur]

@ Eduardo,

I am impressed by your speed and the quality of the KiCad document. 

I definitely need to learn how to use this software !

And you have my agreement for any further development.

I'm the first to be interested if there's a future PCB.

Thank you

A+

[Voyageur]

Eduardo has found a problem in my file 'KIM1mod_CircuitDiagram.pdf'

Here is the modified version :

Thank you Eduardo 

A+

[Eduardo Casino]

Version 2.

There was a mistake in my schematic with some of the signals on the expansion connector. I’ve also tweaked the symbols and placements a bit, and managed to reduce the use of global labels, so it should be more readable now.

@Voyageur, I’m assuming the DP pins on the displays are tied to GND, right?

Eduardo

[Luciano Veronese]

Awesome stuff, thanks for sharing.
Regarding the displays, I am noting that they are both tagged as 3461AS, but the latter is a 4 digit display module. Probably the 2 digit module has a different SKU

And Edoardo, given you have created the Kicad schema, are you planning to build a PCB as well?
Thanks
Luciano

[Eduardo Casino]

Yes, my bad, the small one is a 3621AS. Copy‑paste error when making the symbols :) It’s corrected now.

As I said, I’m in the middle of another project at the moment, but now that I have @Voyageur’s permission, I’ll design the PCB at some point and work out with him how to share it.

Eduardo

[Hans Otten]

Eduardo,

- The 2 digit seven segment should have '3621AS'  as label, connections are OK.

- Pin 7 of the 555 (discharge) should not be connected to 2 (Trigger)  and 6 (Treshold), but go to NMI only.  

Hans

On Wednesday, January 28, 2026 at 1:40:26 PM UTC+1 lver...@gmail.com wrote:

[Eduardo Casino]

Oops, sorry. When dragging things around in KiCad you have to be very careful with the wires, as it sometimes does things like this. Corrected!

The 3621AS was already spotted by @Luciano and fixed in the previous version.

Thanks to both of you!

[Luciano Veronese]

Awesome, it seems that in the future I will have another KIM-1 in addition to the 2 of your replicas I built :-) 
Thanks!

[Hans Otten]

I have collected and documented KIM_1 MOD with the latest information information in this thread.

Hope that is allright?

KIM-1 Mod a portable KIM-1 made by Voyageur – Retro Computing

Hans

[Luciano Veronese]

Very cool stuff, thanks Hans!
When Eduardo generates the Kicad pcb... we can have fun replicating this nice replica
Thanks