Category: Amateur Radio

All things Amateur Radio

Z80 CP/M “Retro” Computer

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In the early 80s I built a homebrew CP/M computer system utilising the Ferguson Big Board.  This system allowed me to “cut my teeth” as a software developer in Assembler and C programming languages that significantly influenced my 42-year career in Information and Communications Technology.  In fact, it is fair to say that Microsoft software development platforms and languages allowed me to raise a family and pay off a mortgage.

Now in retirement, I decided to satisfy my nostalgia for CP/M computers and software development and build a “retro” CP/M computer system.  I chose the Z80-MBC2 design using five ICs which implements the following on a 92mm x 92mm printed circuit board:

  • Zilog Z80 CPU with 4 or 8 MHz selectable clock
  • 128 kB of bank-switched static memory
  • 115,200-bps (USB) serial I/O for the console
  • 16-bits of general purpose parallel I/O
  • Real Time Clock (RTC) module
  • Micro SD Card Module

One of the ICs is an Atmel ATMega32A microcontroller which implements a universal I/O subsystem, ROM emulation (EEPROM), and reset and clock generation for the Z80 CPU.  The I/O subsystem includes 16 x 8 MB virtual disk drives available for the CP/M operating system that are hosted on a Micro SD card.

I also added the optional uTerm board which provides a DEC VT100-like terminal using a VGA monitor and a PS/2 keyboard and is powered by a 9V plug pack which supplies power for both boards.

 

I repurposed an old enclosure that once contained a modem from the 80’s for use with my Z80-MBC2 and uTerm boards and added an image of the IMSAI 8080 computer front panel in homage to that era of 8-bit computing.

I had to join multiple pre-terminated wires to form a gooseneck in the wiring so that the front panel could be removed and lowered to allow the top cover from the enclosure to be slid on or off.

I used an SD card reader extension cable and used double-sided tape to mount the card reader on the back panel.  I also had to make short power, VGA, and PS/2 Keyboard adapter cables to bring the 9V supply, monitor and keyboard connections to the back panel as well.
 

Z80-MBC2a
Z80-MBC2b
Z80-MBC2c
Z80-MBC2d
Z80-MBC2e

I have configured the system to run the CP/M Plus (Version 3, Banked) operating system by default, and have installed the Digital Research macro-assembler/debugging tools, Microsoft assembler, linker, librarian and cross-reference utilities, Hi-Tech C and BDS-C compilers, WordStar 4.0, dBase II 2.43 and any other useful bits of 8-bit software available from the huge, publicly available software archives where CP/M titles have now been released to the public domain.

I am quite pleased with the results and am now looking for a new project. 🙂

FTRestore 1.9.5 Released

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There is an updated version v1.9.5 of FTRestore available for download.  This version is the first general release that adds support for the FT-891 and FTDX5000 model transceivers.  This version also corrects an issue with the Check for Updates… process that resulted after a change in website service provider.

I do not have access to either an FTDX5000 or an FT-891, so all beta/functional testing has been done by other remote users.  All defects identified during that testing have been fixed, but FTDX5000 and FT-891 owners should still consider this release experimental at present.

You can download the new release from the FTRestore page.  The Check for Updates… item on the Help menu will not work in previous versions of FTRestore, but will work again once this new release is installed.

The documentation has been updated as version 1.9.5.1.

QSO Relay v1.9 Released

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The latest release of QSO Relay (v1.9) is now available for download from the QSO Relay page, or by selecting the Check for Updates… option on the QSO Relay menu if you already have an earlier version installed.

This version is a corrective update that contains the following fix:

  • Fixed an error where the ADIF header in the Last QSO API packet sent by JTAlertX v2.50.0 or later was not being parsed correctly.

I apologize for any inconvenience caused.

73 Chris
VK2BYI

FTRestore 1.9 Released

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There is a new version v1.9 of FTRestore available for download. This release adds the DVCODE column to the Chirp CSV import file layout that was added to Chirp subsequent to FTRestore v1.8 being released.

You can download the software from the FTRestore page, or by selecting the Check for Updates… item on the Help menu if you have a previous version of FTRestore installed as well.

The documentation has been updated as version 1.9.0.2.

Ham Radio Deluxe v6.4.0.866 and QSO Forwarding

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Since release 6.4.0.886 of Ham Radio Deluxe, several changes have been made to the QSO Forwarding features in Logbook.  One new feature is a UDP datagram listener for the N1MM Logger+ Broadcasts feature that was first implemented in WSJT-X version 1.9.0. which allows direct, automatic logging of QSOs from WSJT-X to Logbook.  This new feature is great for those users running just WSJT-X and HRD Logbook or other loggers with N1MM compatible interfaces.

For those users like myself who routinely use JTAlertX and possibly QSO Relay, using this new listener allows for an alternative configuration that I have managed to get working.  However, I don’t recommend using it with JTAlertX for a few reasons:

  • JTAlertX continues to support direct logging to HRD Logbook using the Logbook API;
  • it requires a more complicated set of application settings which offers no real advantage;
  • it makes using QSO Relay mandatory and I am happy for it to remain an option.

So, to provide further explanation and to avoid confusion, I have written a paper that describes various scenarios and the configuration options required to successfully implement working configurations.

Alternative Configuration Options
Download 439 KB

In summary, if you are using JTAlertX (with or without QSO Relay), no need to change anything.  If you are using QSO Relay, make sure you are running the latest version (v1.9 as of 2019-10-19).

QSO Relay v1.8 Released

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The latest release of QSO Relay (v1.8) is now available for download from the QSO Relay page, or by selecting the Check for Updates… option on the QSO Relay menu if you already have an earlier version installed.

This version is a corrective update that contains the following fix:

  • Fixed an error where the ADIF header in the Last QSO API packet sent by JTAlertX v2.12.8 or later was not being parsed correctly.

I apologize for any inconvenience caused.

73 Chris
VK2BYI

FTRestore 1.8 Released

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There is a new version v1.8 of FTRestore available for download.  This release adds support for DCS tone mode and code selections for FT-991(A) transceivers, adds partial support for the FTDX5000 model transceiver and fixes a bug in Memory Channel worksheet for the FTDX3000 where the PKT-FM mode was missing from the Mode drop down listbox

You can download the software from the FTRestore page, or by selecting the Check for Updates… item on the Help menu if you have a previous version of FTRestore installed as well.

The documentation has been updated as version 1.8.0.3.

FTRestore 1.7 Released

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There is a new version v1.7 of FTRestore available for download.  This release addresses  the changes in the MAIN/TFT firmware upgrades for the FT-991 and FT-991A released 2017-10-17, which reduced the number of menus from 154 to 153, including changes in menu function for menu numbers 88 through 153.

You can download the software from the FTRestore page, or by selecting the Check for Updates… item on the Help menu if you have a previous version of FTRestore installed.

The documentation hasn’t changed and remains at version 1.6.0.2.

FTRestore v1.6.5 Released

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There is a new version v1.6.5 of FTRestore available for download.  This is a minor corrective release that addresses a bug in the Menu Settings dialog.  The grid column widths were being altered each time a menu worksheet was opened, resulting in grid columns spanning multiple pages in the print layout. The default grid column widths are now preserved, and all columns fit on a single page width in the print layout.

You can download the software from the FTRestore page, or by selecting the Check for Updates… item on the Help menu if you have a previous version of FTRestore installed.

The documentation hasn’t changed and remains at version 1.6.0.2.