SymbOS 4.0 released

[darkhalf]

@Prodatron unfortunately I've had issues with my current setup using symbos 4.0 version with my G9K setup. Finally found some time to isolate the problem

Hardware Configuration: CPC464 + Piotrs DDI4 interface (comprising of DDI clone + 512RAM) + Technobytes V9990 board + M4 board 

Software Config:  New M4 SD card and copied the latest 4.0 SymbOS-CPC40-MassStorage straight onto it

Issues: Only displays 'start' button and task bar when running SYMG9K 

Notes: This setup works fine with upto the last V3 revision (I was testing with 15 Oct 24 build prior) 

I've removed the DDI4 and run directly with the M4 and revaldinho's 512MB RAM expansion in different RAM modes and that is fine. 

So the incompatibility is with the DDI4 itself. I've got a DDI1 but borrowed the chip for my 464+ so can't test that one

Also another interesting error was originally I called the card drive label 'SYMBOS' and was getting CODE 33 (folder errors) and I think the label might have been causing this. I reformatted the card and called it something else and the problem went away

[Prodatron]

Hi @darkhalf , thanks for the report!

I've removed the DDI4 and run directly with the M4 and revaldinho's 512MB RAM expansion in different RAM modes and that is fine.

So the incompatibility is with the DDI4 itself.

So 3.x works with a DDI4 but 4.0 doesn't anymore, hm. I will have a look, what might be special with the DDI4...

Also another interesting error was originally I called the card drive label 'SYMBOS' and was getting CODE 33 (folder errors) and I think the label might have been causing this. I reformatted the card and called it something else and the problem went away

Wow, that's a special find!

I didn't know, that a "volume ID" entry in the root directory can have the same name like a file or subdirectory entry in the same directory. It's not possible for a file and a subdirectory having the same name, but for a volume ID it is.

So when SymbOS tries to open a subdirectory it goes through all directory entries and searches for the name. When it finds the name, it checks, if it is a subdirectory. If it isn't, you get this error message, as it assumes, that it is a file.
Now with the knowledge, that a "volume ID" can have the same name like a file or a subdirectory I will have a look if this can be fixed.

[Brocky]

hackaday finally found SymbOS!

https://hackaday.com/2025/07/19/symbos-is-a-funhouse-mirror-look-at-a-future-that-never-was/

[Gryzor]

hackaday finally found SymbOS!

https://hackaday.com/2025/07/19/symbos-is-a-funhouse-mirror-look-at-a-future-that-never-was/

Good thing I searched before posting it myself, though I think it warrants its own thread😁

[Prodatron]

hackaday finally found SymbOS!

https://hackaday.com/2025/07/19/symbos-is-a-funhouse-mirror-look-at-a-future-that-never-was/

Thanks for the link, very nice article!

It's cool that they mentioned the new SymbOS AI client for ChatGPT and other LLMs by @prevtenet; this information was only posted here on CPC-Wiki so far. As it's still beta I didn't put it on the website yet. So it's interesting that they know/read (?) this forum?

[darkhalf]

So 3.x works with a DDI4 but 4.0 doesn't anymore, hm. I will have a look, what might be special with the DDI4

@Prodatron I've done some more investigation:

The problem is this hardware/software combination: AMSDAP board + V9990 board + M4 board + DDI4 board with V4 of SYMBOS. 

It works fine if:
Go back to SYMBOS V3
Remove the DDI4 board
Remove the AMSDAP board (and run standard MX4 board)
Remove the M4 board (and copy the 9K files onto disk and run it from there)
Run in normal CPC video mode (only a problem in V9990 mode)

Also got it working fine with CPC464 standard backplane + V9990 + DD1 + 512MB expansion + M4 board

I've posted previously about AMSDAP and hardware incompatibility issues and SYMBOS, so I suspect  this is another variation 

Attached is a pic of my 464 running V3 fine with this setup