Archive for March, 2022

GeoPlayer

Sunday, March 27th, 2022

GeoPlayer is a commodore 64 program that play wave file. In order to use this program you have to use a Georam memory expansion cartridge and a 1541disk drive emulator like SD2IEC. GeoPlayer may reproduce sound in two manner. The first is using register 0xD018 of the SID (sound interface device 6581 or 8580), the second and the better is using DigiMax that allow to reproduce sound at 8 bit resolutions. The supported sample rate is 8, 11, 16, 22KHz, sample resolution 8 bit (16 bit is supported too but the program make a downsampling during the upload the file in the GeoRam memory. To create compatibile wave file I use audacity or sox (command line program for unix like os).

Other than play wave file tha program have other feature like play .sid file, show koala image, and last but not least an old fully works assembler monitor SuperMon64 written in the late 1980 by famous guys beind the commodore scene like Wozniak, Baum Jim Russo, Bill Seiler and Jim Butterfield.

The routine that play wave file was from Greg Nacu, the the file browser is a ported of GeoUplod by Skoe ( the aouthr of the famous easyflash cartridge).

If you want to try GeoPlayer without real hardware you can use vice64 emulator. In VICE is possible to emulate all necessary hardware devices like GeoRam, DigiMax, 1541 drive etc.

But if you have solder electronic skills, I suggest too build your own devices. You can find DigiMax gerber in the Vanessa archive, and on HuckUp.net website all neccessary file with step by step istructions to to build a NeoRam cartridge (a GeoRam clone).

The GeoPlayer program can be downloaded from CSDB

I made a video that you can see on YouTube at this link

Have fun 🙂

STM32 SID PLAYER

Saturday, March 26th, 2022

Here I post a project that I build some time ago. For you that like SID music, this is a very cost effective and fun solution. The author of the project is Branko Simic (Bakisha) and you can find all source in your github repository. From here you can download my customized version with with a small i2c oled screen that show information about the current sid tune played.

You can compile the source using the official STM32 core that you can install from arduino IDE or using Roger Clark arduino STM32 core. If you use Roger Clark core you can overclock your bluePill (STM32F103C8) at 128 Khz but you have to use an ST-LINK v2 adapter to upload the code

Bellow some pictures that haep in wiring the hardware and compiling the source.

You can view a small video about my stm32 sid player published on youtube

Have fun 🙂