picmaster wrote on 2025-10-20, 18:22:

Found one interesting issue - there are .ISO files where root catalog is read but you can't access neither files nor directories […]
Show full quote

Found one interesting issue - there are .ISO files where root catalog is read but you can't access neither files nor directories there. And what's very noticeable is the letter's case - filenames have mixed case, not uppercase-only. These are the ISOs:

https://cdimage.debian.org/mirror/cdimage/arc … usinesscard.iso
https://cdimage.debian.org/mirror/cdimage/arc … 386-netinst.iso
(The installation disks also behave the same, but they need jigdo-lite for downloading and I suppose no-one will care)

...

My setup: PicoGUS HW v2.0, firmware v3.7.1, DOS 6.22

Just to be very clear - this is not a heart-breaking issue for me. Just noticed and reported it, in the name of the common good.

I suppose the question is whether they are incompatible with the PicoGUS emulation or with DOS 6.22, the images were made in 2008 and may use features beyond DOS 6.22's capabilities (EG not including 8dot3 backwards compatibility). Did you try a physical drive to see if the images work correctly?

NeoG_ wrote on 2025-10-20, 21:15:

I suppose the question is whether they are incompatible with the PicoGUS emulation or with DOS 6.22, the images were made in 2008 and may use features beyond DOS 6.22's capabilities (EG not including 8dot3 backwards compatibility)

Well, I'm also not excluding cdmke.sys and mscdex.exe from having some related limitations as well. It's a fact that PicGUS is flexible and allows some new unexpected ways to experiment with our retro-systems, and that's when we find these strange behaviors, where the PicoGUS is hardly to be held responsible for these issues.

NeoG_ wrote on 2025-10-20, 21:15:

Did you try a physical drive to see if the images work correctly?

I don't have a Panasonic MKE drive in order to properly reproduce the test case. And also, believe it or not, in my junk pile I don't have a working multi I/O controller to test with IDE cdrom. Damn...

Btw, I tested the same ISO on several virt-manager VMs (debian 12, winxp, win10) and it behaves properly. So maybe the issue is either somewhere in mke driver, mscdex or maybe even the ISO could be generated with improper filename compliance level (e.g. other than Level 1). Maybe I can try same test with DOS 7.1.

Btw, I forgot to say - overall the cdrom emulation is pretty neat, most of the things I tried worked quite well, and PicoGUS is a treasure for some cool experiments!

picmaster wrote on Yesterday, 20:25:

I don't have a Panasonic MKE drive in order to properly reproduce the test case. And also, believe it or not, in my junk pile I don't have a working multi I/O controller to test with IDE cdrom. Damn...

I burned the businesscard iso to a physical disc and tried to read it in my 98SE machine using an IDE drive. The disc reads correctly in windows, but in MS-DOS mode (DOS 7) none of the files can be accessed in the same way you experienced.

Just to follow up on my issue with cracking/popping GUS/SB playback... received a new PicoGUS today and it's the same issue... shall I just assume it's not compatible with VIA Apollo Pro 133 chipset?

wargrip wrote on Today, 14:24:

Just to follow up on my issue with cracking/popping GUS/SB playback... received a new PicoGUS today and it's the same issue... shall I just assume it's not compatible with VIA Apollo Pro 133 chipset?

Plot twist: works fine in XT-Player in GUS mode but Open Cubic Player sounds horrible (volume too low and has the pops/crackles). Maybe I've just been testing it with the wrong thing? Should OCP work with PicoGUS and XM files?

Also Rise of the Triad sounds terrible.