It’s now time to start prototyping the user interface for my RetroMatic 2000 box. As a reminder, the box will have two functions: a video converter to allow an 8-bit micro to be used on a modern monitor, and a USB stick floppy drive emulator.
The plan is to have each function controlled by a rotary-encoder (with a click button) with feedback via 16×2 LCD displays.
In my last update I experienced problems with the i2c interface on my HD9800 video conversion board. I thought I’d fixed it. Sadly, nothing is quite that simple…
After a week’s holiday (including a very enjoyable visit to Spencer Owen’s Nottingham Monthly Hardware Meetup) it’s time to get back to the Retro Challenge.
Most of the big tasks have now been done, so it was time to make a to-do list of all the little jobs left to do.
In my previous posts I flashed HxC firmware onto a Gotek USB floppy emulator, and tested it with my Video Genie.
I’m now going to delve into the intricacies of the Shugart 34 pin floppy disk interface (emulated by the HxC firmware); the jumper settings on the Gotek hardware; and how to extend the hardware to do some cool stuff :-)
In my last post I managed to flash the HxC firmware onto Gotek hardware, add a display, and test it on my Amstrad CPC 6128.
Next up: get it working with my Video Genie II (a TRS-80 clone).
The second part of my retro computer “helper” is to be a floppy drive emulator, to load files off a memory card or stick. This should be more convenient and reliable than physical disks. It will also allow me to transfer files to more modern computers.
My chosen floppy emulator was the HxC: it seems very well designed, and supports almost any format you can imagine.
My RetroMatic 2000 project has two halves – so far I’ve been working on the first half: a module that converts a weird video signal from a 1980s computer to clean VGA.
Before starting work on the second half (a floppy drive emulator to load software onto these machines), I’ve been having a think about the final aesthetics of my project.
In my last three posts, I prototyped getting an HD9800 video conversion board to accept signals from my old computers and display them reasonably satisfactorily on an LCD VGA monitor.
But there is one major difference between the original video and the VGA signal: scanlines.
After my testing of the HD9800 video converter board, I wanted to experiment with reprogramming the TV5725 video conversion chip on the board.
A number of people have already done sterling work on reverse engineering it to invoke modes not supported by the supplied on-screen controller.
I hope to build on their work :-)
After my initial research and designs, I started ordering components for the video converter part of my RetroMatic 2000.
It’s based around a GBS8200 board (or the HD9800 clone version), with extra circuits to modify the input (clean up the sync signal) and output (generate scanlines).
Here’s a scrapbook from my prototyping phase…