What is this? 1ChipMSX and SG-1000

Supporter (6)

15-12-2016, 18:06

The second link on this website contains a link to a MSX program and some firmware file. I do not understand Japanese and the Google translation doesn't help either. This could be a way to modify the 1ChipMSX to play SG-1000 games with the provided program. Here is a video on YouTube showing everything in action: https://www.youtube.com/watch?v=Grf3rXQkRhc

By gdx

Enlighted (6104)

16-12-2016, 00:43

It's easy to program the 1ChipMSX to make it an SG-1000 but not to make it an MSX and a SG-1000 at the same time. Moreover the FPGA can only be programmed a certain number of times.

By gdx

Enlighted (6104)

16-12-2016, 11:20

Apparently He gives a ZIP that contains a VHD file to add the emulation of the sound chip SN76489 for the OCM based on the Altera DE0 and a SG-1000 game loader for MSX-DOS2.

http://www.geocities.jp/parallel_computer_inc/SG1K.zip

By cons, be careful because the I/O port used for the SN76489 is the same as for the Moonsound.

By pcfreak324

Supporter (6)

16-12-2016, 14:36

Thank you gdx for the information.

I wasn't aware of the fact that the 1ChipMSX can only be programmed a certain number of times. Is it because the flash chip that stores the programming only has a limited number of write cycles?

I'm searching for a way to play SG-1000 games either on my MiST FPGA with the MSX core or on the 1ChipMSX. I do know that the Playsoniq can be used to achieve the same results but for me it causes sound interference. Therefore I would prefer a way to reprogram the FPGA.

Is it possible to edit the file "EMSX_TOP.QSF" so that the I/O port used for the SN76489 sound chip doesn't interfere with the I/O port used for the YMF278B (OPL4) sound chip? If so, which text line(s) must be edited (with Notepad)?

How can the FPGA be reprogrammed?

By gdx

Enlighted (6104)

16-12-2016, 15:43

The OCM do not mix the sound input of the cartridge slots with the internal sound output so it often causes problems, or it is the filter of the Playsoniq is not effective.

By RetroTechie

Paragon (1563)

16-12-2016, 21:13

gdx wrote:

Moreover the FPGA can only be programmed a certain number of times.

Huh? Article talks about the Altera DE0 board. Which uses a Cyclone III FPGA, which (like most FPGA's) is SRAM-based. So FPGA config can be changed as often as desired.

Default config is stored in a serial Flash chip (Altera EPCS device) which according to datasheet has:

Quote:

Reprogrammable memory with more than 100,000 erase or program cycles

For the original 1chipMSX it's the same. In other words: re-configure your FPGA board as often as you like. The on-board SD card socket will likely wear out first!

Btw for development, you may not want to re-program the boot flash anyway. Easier to leave a programming cable attached, and re-configure the FPGA ('s SRAM) only. A power off / power on cycle, and the default config from serial Flash is back.