Will | June 12, 2022

Fantastic Kit and great Maker

For PAL-1 - A MOS 6502 powered Computer Kit

Bought my PAL-1, and when it arrived, I soldered it up and when I ran into issues, I got quick help. The Kit was flawless and once I straightened out my mistakes, worked beautifully. If you are looking for a great 6502 trainer that is reminiscent of the KIM-1, this is the ticket.

I got the PAL-1, the motherboard expansion, and the 2nd RIOT at the same time. The PAL-1 was the most labor intensive to put together, but the motherboard had its share of soldering - lots and lots of pins :). The 2nd RIOT took about 5 minutes. All of the kits had all of their parts and went together smoothly. They all pretty much "just worked".

Response from KJXZZ | June 13, 2022

So glad you liked the kit~ Thanks for your review!

Dominic | Dec. 1, 2021

It's a real KIM

For PAL-1 - A MOS 6502 powered Computer Kit

Assembled and tested a hello program in two hours. Very nice. I collect KIMs but prefer replicas for everyday use.

I made an assembly video and will post it to YouTube.

Great features include the sturdy PCB. large, positive click feeling keypad keys.
Large digits, rs232 serial port integrated into the board. Just right size. Easy assembly, not an emulated KIM.. this is real hardware and clearly designed with care.

Minor design quibbles.... The kbd/serial selector should be a SPST switch, not a jumper. I'd like to see an on/off switch (nice but not necessary) and the keys are labeled at the bottom and this confuses me while searching for the right key to press I keep getting the wrong row because my eyes expect the label to be above the key. I'll label the keys myself to solve that.


I hope you make and sell thousands of these.

Shipping was five weeks to USA.

Response from KJXZZ | Dec. 1, 2021

Thank you for your review!

May a version E of PAL-1 is needed to optimize the two jumpers (replaced with two switches). I will try a version E after current version D PCB sold out.

David | Nov. 17, 2021

David | Oct. 16, 2021

Great kit with great detail BOM documention

For PAL-1 - A MOS 6502 powered Computer Kit

Great kit that was easy to build using the BOM that came with the kit. Just need some more parts for the PAL-1 that I didn't buy the first time. And I just need to brush up my programming skills from the past to have some fun with this kit

Response from KJXZZ | Oct. 16, 2021

Thank you!

Hope you can get back a lot of fun from the past with the little kit.

Christian | July 29, 2021

Best 6502 kit on the market!

For PAL-1 - A MOS 6502 powered Computer Kit

I've been building a lot of 6502 and Z80 computers lately, and PAL-1 is the best 6502 kit I've found. This is a clone of the MicroKIM which is itself a slightly miniaturized but still true to form KIM. The board runs the actual KIM ROMs, no emulator here.

Construction is simple, parts are well labelled and high quality. I bought RIOT/RAM/ROM/Motherboard/Tape kit and it all went together very quickly. I don't think I'm going to use the tape adaptor but it's nice to have.

Response from KJXZZ | July 29, 2021

Thank you for your review!

Real hardware with vintage software feels great!

Peter | May 20, 2021

Excellent kit

For PAL-1 - A MOS 6502 powered Computer Kit

Great kit. Good price. Took a while to get here. Well presented. Quality parts. Easy to build. Worked first time.

Response from KJXZZ | May 21, 2021

Thank you for your review!

Happy hacking 6502!

Theo | March 12, 2021

High quality kit and great fun to build

For PAL-1 - A MOS 6502 powered Computer Kit

Good quality printed circuit boards, easy to solder with nice fitting of components and clear labeling.
Worked first time, so that was a fun experience without any frustration. I like the big buttons and the large LED displays.
I have pasted a strip of red Lee color filter over the displays because they were rather bright for my eyes, and they look great.
The new user manuals are fine and in the download I found lots of KIM-1 and 6502 documentation.
I included the optional motherboard with RAM and RIOT in my order, and they were also fun and easy to build.
Have not done much programming yet but so far so good and I would recommend this kit for any retro-computing fan that would like to have some 1970's KIM-1 experience.

Response from KJXZZ | March 17, 2021

Thank you for your review!

Wish this KIM-1 clone will bring you a happy experience.

Guus | March 12, 2021

Board is fine and worked just from the start.

For PAL-1 - A MOS 6502 powered Computer Kit

Very nice implementation. Board worked right away.
Assembly was fast and all components do fit just fine.
I mounted a heartsink to the voltage regulator.
Will replace the CPU by a 65C02 later on, just because I can. :-)

Hints for improvement:
- Put a protection diode across the voltage regulator. This may be needed if the board gets power from the expansion connector.
- Make a footprint to accomodate both the small (Square) oscillator and the bigger one. This way, another frequency can be fitted easier.

Response from KJXZZ | March 17, 2021

Thank you for your review!

About the 65C02 upgrade, the SST switch will not function normally, you can check this picture on hans' site: http://retro.hansotten.nl/wp-content/uploads/2021/01/Single-Step_Fix.jpg to fix the SST problem while using 65C02.

Philippe | Feb. 10, 2021

Excellent! A good source of old fashioned fun!

For PAL-1 - A MOS 6502 powered Computer Kit

Soldering everything took me about two hours.

Some soldering pads are really, really close together (all the transistors), and I managed to create a short. Even though I identified and fixed the problem relatively quickly, that seems to have damaged the 6532. I got a few hours of fun, but eventually the 6532 gave up the ghost (only the last two digits where showing and the board was pretty much unresponsive). I bought a new RIOT from a local vendor (thank God for those dusty shops that still have stock from the 80s) and the board is now running properly.

My biggest gripe is the the DB9 serial port. It is a pain. I understand striving for historical accuracy, but some things like RS-232 are better left in the past where nobody is missing them. I spent a small fortune on cables, RS-232 level shifters, gender changers, and null-modem adapters before I could find a solution that works with the PC that I use as a terminal. I suggest to include pads on the PCB to solder a USB to serial adapter permanently. That would give instant, no grief USB connectivity and power and would save a few components including the power regulation section and the DB9 connector. The only incentive to keep RS232 over a DB9/DB25 connector would be to connect vintage equipment, and the components for that could be sold to interested parties as a separate kit (and include a real level shifter to achieve real RS232 levels).

As far as documentation and design files, it's all very minimal and cannot really qualify as open source. There is definitely room for improvement.

Thank you M. Liu. I hope you take constructive criticism well ;-) Whenever you come up with v. 2.0, let me know!

Response from KJXZZ | Feb. 24, 2021

Thank you!

The 6532 chip, which hard to find nowadays, comes from recycle/refurbish supplier.

Even though I always check the working status before packaging each kit, there is still a certain probability get a flaw chip, such as long-term stability.
If I can shipping you another package in the future, I can send you another 6532 for backup.

The serial port is for historical accuracy, your suggestion may apply on a brand new 8-bit computer in the future.

Regarding documentation, you can find a lot of documentation at http://retro.hansotten.nl/6502-sbc/, hope you can find what you need.

Thank you again for your useful comments!

Jim | Jan. 24, 2021

Great little kit!

For PAL-1 - A MOS 6502 powered Computer Kit

My first computer was 6502 based (OSI C1P) and this has been fun to play with. The kit went together fairly easily, but there are no step-by-step instructions so it isn't for the beginner. But if you've done some building, this one is fairly easy to figure out. As has been mentioned, the pads for the transistors are a bit close together. When I first powered up, the right digit was dead. I looked a the schematic and then remembered I had a solder bridge with one of the transistors that I thought I'd cleaned out. Turns out I hadn't cleaned it good enough and a few minutes with the solder sucker and the soldering iron had things working as they should. Buttons have a nice feel to them. The voltage regulator runs a bit warm even at 6 volts (and really warm at 7 volts), so I'll probably add a heatsink (I have a collection of salvaged ones, so why not..). The design is similar to a previous clone, but I like the way the LEDs are down near the keypad. They are large and bright. Overall a great kit!!!

Response from KJXZZ | Feb. 24, 2021

Thank you!
I'll try to create some "video manual" for the system.

and, transistor pads are upgraded in REV. D.

Tim | Jan. 16, 2021

Very nice kit.

For PAL-1 - A MOS 6502 powered Computer Kit

As I said, a very nice kit (high quality PCB, well packed etc). It took me about five/six hours to build and was pretty straight forward. A bit tricky for a beginner. The only fiddely bits were the transisters which had very close pads, I would lay them out with a little more space (even if the builder has to spread the legs a little they would still be easier to solder). I also like the chunky tact switches.

I've had a few hours play with the kit and it's a very good replica of the KIM-1. The missing second RIOT chip means that a lot of the vintage hardware projects can't be easily replicated. I would suggest that a little expander kit would be a good idea for this. I might try and find a chip online and build it fo myself (the extender bus is good for this).

I keyed in a few programs and all worked as expected. I also used the serial interface (using Tera Term on my PC) and all worked well. I found original manuals, articles etc. online very easily and there is lots of interesting stuff if you want to explore a very interesting point in micro-computer history. I myself started in the business around 1979/1980 but all my early experiences were with Z80 based computers (Nascom 2 & CP/M) so I was interested in digging into an early 6502 board.

Just a few notes on my review/scores.

Product - *****
See above.

Shipping - *****
Shipped the day after I ordered it. Took 4 weeks to get here but I kinda expected that (from China, Covid, Christmas etc.)

Documention - ***
Ok, I had no problems but I have a lot of build experience. Beginner might find it tricky. Build order guide and a few more pictures would help.

Communication - ****
Good, there was a littlle hand written note in the box. I sent an email to seller to let him know I enjoyed the kit etc. and he replied.

In summary, I would recommend this kit and think it's good value at this price.

Response from KJXZZ | Feb. 24, 2021

Thank you for your LONG and USEFUL review!

The expansion kit manual is written according to your suggestion of documentation.