All posts by scc

Hardware

ZIF sockets

If you want to fit a zero insertion force (ZIF) socket you might like to consider this strategy.

Most PCB designs do not allow for ZIF sockets to be soldered directly to the PCB. The holes are not usually big enough for the sturdy ZIF socket pins and there are usually other components too close for the ZIF socket’s larger footprint.

By raising the ZIF socket with an intermediate IC socket or two the ZIF socket is raised clear of most other components and the large ZIF socket pins do not need to fit the holes in the PCB or damage the soldered in IC socket. The ZIF socket pins can be jammed into cheap IC sockets but not turned pin sockets. This method has proven convenient and reliable. I guess it would not stand being shaken around but for development and static systems it is fine.

Software

SCM v1.2 Beta

A new version of the Small Computer Monitor (SCM) is now available.

Version 1.2 adds a framework to enable most configurations to be created with simple text files thus reducing the need to manage so many code files. It also makes it easier to add support for new devices, such as serial interfaces. The increased code size required to support these new features means the fully featured monitor does not fit in an 8k ROM.

SCM v1.2 is currently a Beta release and is not yet being used for ‘production’ firmware.

Software

RomWBW v3.0 Released

RomWBW version 3.0 is now available.

Important points to note about v3.0:

  • The default baud rate for SCxxx products is now 115200.
  • Drive letter assignment is different to earlier releases

Full details, source code, and documentation is available on GitHub.

ROM images for SCxxx products can be found here:

Upgrade instructions can be found here.

This is a very significant milestone for RomWBW. Well done Wayne.

RomWBW v3.0 will be included in new SC131, 130, 126, and 119 kits as soon as the current stock is exhausted.

Hardware

SC132 SIO/0 Released

SC132 is a two channel asynchronous serial port module designed for the RC2014 bus.

This module is based on the Z80 SIO/0 chip which is currently more readily available than the usual SIO/2 chip. It is software compatible with the SIO/2 and thus with existing software.

Details here.

Hardware

Pocket RomWBW System

Today, I finally received the batch of PCBs I’ve been waiting for from China since January 14.

These boards are for my prototype pocket RomWBW system.

Front view.jpg
SC131 RomWBW CP/M Computer

I’ve got a few tweaks and some testing to do and then I intend to offer it as a kit. I plan to offer a choice of case colours and a choice of front and back panel colours.

SC131 circuit board

Specifications:

  • Z180 CPU running at 18.432MHz
  • 512k Flash
  • 512k RAM
  • 2 serial ports
  • MicroSD card slot
  • No further expansion if possible
Next to SC126 for scale
The case is available in several colours
Viewed with top of case removed
View of back panel
Top view next to SC126 (for scale)

Comment

2019 Reviewed

2 Comments

2019 has been a good year for the homebrew retro computer community.

In the RC2014 universe there have been quite a few new releases, including kits:

RomWBW has become widely available on RC2014 related designs bringing a great CP/M environment to the masses.

I’ve also made significant progress this year.

I started selling kits on Tindie in February 2019 but things really got moving in mid-July when I launched SC126 Z180 SBC/motherboard kit. I have now sold 180 SC126 kits. With some sales of the PCB only, and others getting their own boards manufactured, I believe there are now more than 200 of this design out there.

One downside of selling kits is that I have had much less time for new projects 😦

The RC2014 based community now includes many very talented, experienced, and active members. During the last year or two, the sophistication of many community generated add-ons for RC2014 has increased significantly. This ultimately led to Spencer restating his goals for the RC2014. With many of the new RC2014 based activities clearly not consistent with Spencer’s goals for the RC2014, a new google group was formed for those wanting to go further.

So what will 2020 have in store for our community?

I fully expect the level activity to increase and for the limits to be pushed further. Personally, I’m not particularly focused on exotic designs and applications. I’ve always liked the idea that designs and products should improve the experience for the majority, rather than push the limits for the few.

I hope to design some more kits and I know some others are planning their own developments. I’m sure many in the community will be doing great things for their own satisfaction and not to design “products” for others. Some of these we will probably never hear about. Fortunately, there is room for all interests and motivations.

So 2020 is looking like another good year for our community.

Happy New Year,

Steve