Tindie

Name: SC126 Z180 SBC / Motherboard Kit
SKU: 17487
Price: 58.00 USD
Availability: InStock
Rating: 4.82 (22 reviews)

SC126 Z180 SBC / Motherboard Kit

(22 Reviews)

An expandable Z180 motherboard supplied with RomWBW (including CP/M)

Designed by Stephen C Cousins in United Kingdom

2019-07-15T16:51:05.728Z-SC126 v1.0 Assembled - 3x2 - 3048x2032.jpg

2019-07-17T07:56:00.455Z-SC126 v1.0 Accessories - 3x2 - 3318x2212 - with label.jpg

2019-10-22T08:42:41.488Z-SC126 v1.0 Kit Boxed 2 - 3x2 - 2935x1957.jpg

2019-07-15T16:51:05.728Z-SC126 v1.0 Kit Contents - 3x2 - 3729x2640.jpg

2019-07-15T16:51:05.728Z-SC126 v1.0 PCB Image - 3x2 - Green - Top.jpg

2019-08-13T10:57:41.208Z-SC126 v1.0 PCB Image - 3x2 - Green - Bottom.jpg

2019-10-22T08:53:17.705Z-SC126 v1.0 In Use 2 - 3x2 - 4134x2800 - a.jpg

2019-10-22T08:53:17.705Z-SC126 v1.0 With 2 FTDI modules - 3x2 - a.jpg

2019-10-22T08:53:17.705Z-SC126 v1.0 In Use - 3x2 - 3719x2479 - a.jpg

An expandable Z180 motherboard supplied with RomWBW (including CP/M)

The motherboard kit comprises parts to build a Single Board Computer with these main features: Z180 CPU running at 18.432 MHz 512k byte RAM 512k byte Flash containing RomWBW 512k byte Flash contai...

Documentation

The documentation can be found at www.scc.me.uk

Purchasing the PCB only

The bare PCB is available here on Tindie.

Dimensions

The assembled kit is approximately 10cm (4") x 17cm (7") x 6cm (2.5"). It is supplied in a box approximately 23cm (9") x 16cm (6.5") x 2.5cm (1") weighing about 300g (0.7lbs).

Notes

This product is supplied as a kit of parts which require assembly.
It is your responsibility to pay any import duty or taxes charged by your home country.
This product is designed for hobby use and is not suitable for industrial, commercial or safety-critical applications.

Rates to United States of America

Shipping Rate	Ships From	First item	Additional items
Royal Mail: International Standard, no tracking, no signature (WW/M)	GB	$7.29	$2.54

Review Breakdown

Average Ratings

Product: (4.00)

Documentation: (4.00)

Shipping: (4.00)

Communication: (4.00)

David | Jan. 24, 2020

A Great Design, Well Documented, and Simple to Build

First impressions mean a lot. What hit me first about this kit is how compact the design is: at overall dimension of 4" X 6.5" (101 mm X 165 mm), this system is quite compact. It took a couple of days on and off for me to build, but the documentation is clearly written (especially the assembly guide, troubleshooting guide, and user's guide), so making the checks necessary to ensure a successful build before power up are duck soup for anyone who knows how to use a multimeter.

The soldering is somewhat fine work, so having an iron with a finer tip and good heat transfer is imperative. With my aging eyes, use of a stand magnifier was very helpful, but someone with normal vision will find no challenges so long as they are familiar with good soldering and electronic construction techniques. One strong suggestion: READ and FOLLOW the assembly guide. This is the best path forward to a successful build.

There are provisions on the board for such niceties as a remote reset switch, and multiple paths for supplying system power (5 VDC at less than 0.1 a), obvious signs the designer anticipated people building these systems into cases. I definitely have plans for mine.

The included firmware makes this machine truly versatile, able to boot straight to BASIC, FORTH, Z-System, CP/M 2.2, the system Monitor, or from systems stored on any available bootable media (microSD card in my case).

CP/M is an 8-bit system that usually only has 64K of RAM available, and most CP/M systems back in the day ran around 2 to 6 MHZ, with the latter being rare. . This design, with its Z180 CPU, is capable of operating all day long from a USB battery pack (I'm using a 10,000 ma-hour pack presently) at 18.432 MHz, so very fast, and very powerful for an 8-bit system.

Be aware that a serial terminal is needed to communicate with this system. The optional serial adapters sold for the board are well worth having, and will make interfacing this system to serial terminal emulator software like minicom or TeraTerm a simple matter.

My kit took about two weeks to get to the Gulf Coast of the United States from the UK, probably because of heightened security associated with current events (U.S. Customs probably suspected it was a noo-kyoo-lur dee-vice...), but most folks get their kits a bit sooner. It was packed well, and arrived with all components in good condition, ready to go.

There is a strong but small community on the net supporting this system and doing interesting things with it. I hope to see you there!

Mark | Dec. 30, 2019

Great kit - a lot of fun!

The last time I built a kit was in my childhood (which was more than a few years ago) so I was a bit apprehensive. The instructions were remarkably clear. The circuit board very well laid out. The periodic tests instilled a lot of confidence. The best part? It arrived in the mail Friday evening, I sat down Saturday morning and by that evening I had a working cp/m machine right out of the 1980s! Everything worked exactly as advertised. Amazed that this cost as little as it does when compared to other z80 kits out there. Really an amazing value.

Wondering what others are doing for cases?

Craig | Dec. 16, 2019

I love it!

I had my kit built in a few hours; within an hour of it being up it was running fuzix.
Thanks to Stephen Cousins for the well designed and documented machine, and to Christopher David Farrar for the write up:
How to create an sd card for booting fuzix on an sc126

In linux do the following steps:

Drop the two image files into a directory or on the desktop.
I chose desktop.

Bring up a bash command prompt.

Change to directoy where you have placed following files:

- c126-0.3.ide
- s32m.z80

enter commands:

sudo dd if=sc126-0.3.ide skip=2 of=/dev/sdb conv=notrunc,fdatasync status=progress

sudo fdisk /dev/sdb

Once in fdisk do the following steps:

- list partitions with p command
- delete any partitions with d command
- create new partition with n command
- specify partition 1 - default
- specify 2048 starting block - default
- specify +64mb or let rest of sd card be used
- change partition type with t command
- specify partition 1 - default
- specify partition type 7e
- write changes to disk and exit with w command

if you create a 64mb partition above instead of using rest of card, you can add
other partitions like a fat16 or fat32. The fuzix should ignore them.

Once back in bash do the following:

enter command:

sudo dd if=fs32m.z80 of=/dev/sdb1 conv=notrunc,fdatasync status=progress

You are finished!!!!! :D

Greg | Dec. 13, 2019

Probably the best retro-kit available

I really like this kit. It is a very capable system on a single board. Less overall pins to solder than some other kits and has greater functionality. Other kits too closely follow the MITS 8800 paradigm: You get it together and you have no storage and limited I/O. The SC126 has mini SD Ram storage. Quality is very high, and the CPU provides integrated peripherals. If you are trying to decide which kit to assemble, look closely at this one.

Ramon | Dec. 2, 2019

The best kit i have.

Easy to solder (i am 50, and the "new" smd formats are dificult without magnifier, but this was really easy (1 hour and half aprox)

The board is really fast running Z80 code.

Now i want to port MPM to this board.

Hans | Nov. 23, 2019

This kit is too good!

It took me an afternoon to assemble this kit, download Turbo Pascal, WordStar and dBase II and run them like it was 1984! Highly recommended!

Michael | Nov. 22, 2019

Excellent board and great documentation

When I was a kid, I had a few home computers, but the one I remember the most was the Coleco Adam (with a Z80 processor). I stayed up late writing BASIC programs and even ventured into CP/M 2.2 and assembler at one point.

Fast forward to 2018, when I started following the retro computer scene. I watched ebay for some classic computers, but I wanted something that I could build myself. So I searched around for a kit based on the Z80. I eventually found Steve's Small Computer Central website which led me to his Tindie store. I bought myself the SC126 a few weeks ago. I chose it over the SC130 because it has Small Computer Monitor in addition to ROMWBW, even though it's a more complicated kit to assemble.

He shipped it the same day I ordered it and it arrived in the USA a week later. The kit was packaged well in a compact box with a great parts list with images of all of the parts on it and a link to the build instructions. After checking that I had all the parts, I printed out the instructions and started soldering. I must warn beginner and intermediate hobbyists, you should follow his testing procedures carefully. I thought I knew what I was doing and started poking a live 5v wire around the resistor on the power LED and managed to blow it. I should have read the instructions first.

Aside from the blown power indicator LED (which was completely my fault), the kit ran on the first power up.

I've already spent hours playing with the onboard LEDs and writing code in BASIC as well as C using the great z88dk and the newly minted SC130/SC126 capabilities it offers. I also ordered the SD card reader so that I can have "hard disk" storage with CP/M. I'm having a total blast with this kit.

I'm looking forward to ordering some PC boards from the various community designs that are out there for the bus and even designing my own at some point.

That leads me to documentation. Steve's documentation is incredible. I've not only been able to easily build this kit, but I've also learned a lot about how the board addressing and the Z80 processor works from his website.

The community around these boards is friendly and welcoming and they've got some amazing ideas. I'm probably going to buy the SC130 just because I want to build another kit. This one is a lot of fun.

Ross | Nov. 3, 2019

Great little kit, exceptional documentation.

A great little through-hole kit that can be put together on the kitchen table in a couple hours or less into a working 8-bit computer that has the same retro user feel (but smaller and faster) as the early 1980's homebrew and commercial machines. The online documentation is exceptional- user's guide, circuit description, detailed assembly instructions, ROMs- all of it right there.

Richard | Oct. 28, 2019

Amazing kit, a must buy for tinkerers!

Fantastic kit, and incredibly well documented. I found this to be a "medium" skill level assembly, but if you're patient and follow the instructions you will have no issues. Check out the documentation on the website first to ensure you are comfortable assembling. Great price, worked flawlessly, would definitely purchase from seller again!

Martin | Oct. 25, 2019

Very well put together kit for Z180

The documentation is excellent, it was very easy to put together correctly. Worked on first try. I highly recommend this kit for anyone wanting to get into Z80 type RC2014 echo system of retro computers. /Martin

Randy | Oct. 25, 2019

Great kit design with great instructions for a low price

This kit was mostly easy to assemble, even with the large number of solder points, but low parts count. Some of the ground-plane solder points took a lot of time to get hot enough for solder to flow, as they nearly fully surrounded with copper. Having two vertical expansion slots plus one horizontal backplane expansion slot is fantastic and I've had great success with multiple RC2014-style cards inserted. SD card adapter and serial adapter worked without any problems and I had a fully-functional serial CP/M system in very little time. The included parts sheet is very useful and the online assembly instructions were clear and organized well, and included testing instructions along the way to verify critical points (much appreciated). Shipping took a little long (from UK to US), and there wasn't an option for a tracking number that I saw, so it was a bit of a wait, but the box was well packed and arrived in great condition. I'm looking forward to more kits from this Maker. Fantastic value for the price!

Donald | Oct. 11, 2019

Fun new dev board

I'm enjoying using the new SC126 development board based on the Z180.
My only complaint is that the manual needs to be gone through with a fine-tooth comb so ppl know which jumper does what. Just because the SC130 has been released recently is NO excuse to not go back and clean things up. Thanks.

Response from Stephen C Cousins | Oct. 17, 2019

Thanks for the feedback.
Jumper settings are described in the SC126 User Guide. I just checked this document and it does describe the function of each of the jumpers. I did, however, find one mistake which I have now corrected.
I have also added a link to the user guide in the section of the assembly guide where it illustrates the initial jumper settings for testing the board. Hopefully, that will make it more obvious where to find further details.

Randall | Sept. 23, 2019

Just get one!

Really cool little Z180 System. The Assembly guide is full of detail making it a very simple systems to build. Even if you soldering skills are less than perfect or your knowledge of electronics limited, I can recommend this kit.

All the documentation on Stephens web site is amazing, everything from the schematic to the firmware and software is easily acessible. References to the source for the software and for the firmware is included and makes tweaking up your SC126 very easy.

It took me roughly 3 and a half hours to build and get it running and once it was up it took little effort to flash the latest software to the flash ROM. And the old floppy drive and RC2014 floppy controller I have, worked perfectly almost out of the box, so to speak.

Great project, awesome kit and a joy to play with.

Thanks Stephen.

Wesley | Sept. 12, 2019

What a great computer

I've bought and built a lot of RC2014 stuff, and this board is just a standout. Good design, really well thought-out, and I have to appreciate how much it does with so few chips. I mean, there's a lot of chips on this board - but it essentially functions as 6 cards (CPU, Clock, RAM/ROM, Serial, Storage, RTC) in a regular RC2014 system, while still providing extra features. And only using 6 pieces of glue logic, and comes with a bunch of software ready-to-go, and did I mention it's *fast*?
Extra credit given for the documentation. Especially the provided inventory sheet, for organizing the components prior to installation. Other sellers take note!

Tuukka | Sept. 10, 2019

Great product at low price!

The kit arrived fast, and was very easy to assemble. A few hours after opening the package I was up and running the RomWBW CP/M - of course it depends on your soldering skills, but the board is easy to solder and silkscreened on both sides. I was prepared to flash the monitor roms myself, but even that was not necessary since the kit included ready to run flash chips!

Assembly instructions are very good - follow those and you just can't get it wrong. Some experimentation was needed in getting an SD card formatted and running CP/M, it was not crystal clear whether you should use the WBW or SCM monitor ROM. But carefully reading all documents resulted in success.

Even a one liner documentation comment on the ROM-drive CP/M programs would be useful. Some info can be found on RomWBW github page, and some by just running the programs. I installed an xmodem file transfer program, and only shortly after that noticed there was XM.COM already on the rom-drive.

Anyway, half the fun is finding out what you have. And with this kit, you have plenty to discover!

Response from Stephen C Cousins | Sept. 11, 2019

Thanks for the feedback. I've now added a note and a few links at the end of the assembly guide. There is information on my site about preparing an SD card etc. but I can see how you were left without guidance at the end of the assembly. Hopefully, the additional notes and links will help.

Chris | Sept. 5, 2019

This project was a pleasant one day build and worked first t

I loved building this project and it worked on first try. I also added a smbaker floppy controller to it which worked flawlessly after a re-configuration and rebuild of the romwbw software.

Jim | Sept. 5, 2019

A really nice project

This is a really well thought out and executed kit. It took just a week for it to arrive in the Southwestern United States from the U.K.

Upon opening the box, you'll find a great chart that has pictures of each part and the quantity you should have. My kit had NO missing parts. The assembly instructions are on the maker's website - and they are wonderful, step by step, clear directions. The on-board 8 LEDs were pretty, but functional - each ROM has a different startup pattern. Quite useful to know on first power up that you got it right.

Since the project contains two ROMs, the SCC Monitor and RomWBW, you can chose which to boot. RomWBW contains CP/M 2.2 and a Z-system variant so you can be up and running CP/M in no time. You'll need to source a small micro-SD card for storage, but this is pretty easy. I had a 64K card in the parts bin that worked just fine.

The board and parts are good quality. The board is silk screened on both sides to make it easy to locate and place parts. All in all, this was a pleasant project that went together quickly and worked the first time.

Karl Albert | Sept. 3, 2019

Power without the price.

If you are new to Z80/Z180 based soldering projects, this kit is not for you. The seller is offering another kit SC114 Z80 motherboard (https://www.tindie.com/products/tindiescx/sc114-z80-motherboard-kit-for-rc2014/) which is perfect for beginners. This kit is also very useful when building more modules as it will help with any troubleshooting.

The SC126 kit arrived quickly and came nicely packed in a card box, containing all the parts in neat plastic bags. With the package came also a poster showing all the included parts. Detailed assembly instructions and documentation of the kit is on the sellers home page. The system is relatively powerful compared to kits that cost far more. The heart of the system is the Z180 processor, which is basically a Z80 processor but with a lot of extra features like, a memory management unit (DMA), a counter-timer-clock (CTC) unit, and two serial ports. The system has also I2C and SPI ports, and a real-time clock. With a simple jumper, the system can run two bootloaders, the ROMWBW and SC-monitor, giving access to CP/M. Another nice feature is that is can be used to write to flash memory. And with the expandability, it is all in all a very capable system. Assembling this kit can be a challenge for beginners, but the instructions are very good and contain also troubleshooting guide.

Highly Recommended.

Michael | Aug. 30, 2019

Brilliant value SBC kit.

Good thoughtful design, well documented with instructions for testing at several stages of the assembly. High quality PCB, all components provided. Recommended for all but the absolute beginner (who might find the SC114 a good first project). Great price!

John | Aug. 27, 2019

Very Good!

I found this SC126 ver 1.0 to be a first class kit very easy to assemble and worked fist time! And the software supplied also very good!
My interest is purely nostalgic! Way back when, a local company had a problem the were paying £35.00 for a IBM formatted 8 inch disk, to solve there problem I purchased an old S100 computer with 2 X 8 inch drives and a VT100 terminal with CPM 2.2 ( lost the makers name!), I sold the formatted disks for £15.00, soon paid for the computer!
The S100 had disc’s for CPM 2.2, Wordstar, Supper Calc and others, this was my start on CPM, I found it fast and very useful, once I got used to the keyboard short cuts!
I purchased a Ampro Littel Board Z80 CPM 2.2 small PCB fits on a 5.25 inch floppy drive, very good PCB one of the best things was the ability to read lots of 5.25 inch formats.
Some years later moved to IBM PC.
I now would like to experience CPM 2.2 once more.
John Worden

Leif | Aug. 26, 2019

Great product but not for the beginner in soldering

Had been looking for a Z180 based product quite some time and was considering the RC2014 with an addon board. But then this showed up and with brexit coming it was best to act quickly.

Delivery was quick. 8 days from UK to SE of which I suspect the most was here in Sweden. It was posted the same day as ordered.

Took good time to read all the instructions available on the homepage before doing any soldering. Good instructions even if I choose to do things in a slightly different order. The only thing I miss is a bit more information on the included software. But it could be just that I have not looked close enough. There is plenty of information on ROMWBW, CP/M and ZSDOS on the internet. You just need to filter to find what's relevant and what's not for exactly this product.

The kit is complete down to the last little resistor and even includes some rubber feet. PCB was of high quality as far as I could tell. But one thing that might make this unsuitable for beginners in soldering is the thermal reliefs for pins connected to the ground plane. Some of these gave me a real problem and I consider myself as experienced.

Now, if there only was a matching graphics card to mount piggyback to this board....

Response from Stephen C Cousins | Sept. 11, 2019

Thanks for the feedback.
I think you are correct, there needs to be more information about the included software. There is quite a bit on my website, especially about the Small Computer Monitor, but I need to add more to better explain the rest. I also note the point about how this documentation needs to relate to specific products.
The issue of thermal reliefs is an interesting one, thanks. I'll try to improve this on any updates to SC126 and on future designs.