SD Padial on Panasonic FS-A1

Paragon (1134)

16-08-2023, 22:10

Hello,

In recent years, I've been using my SD Padial (RIP) cartridge a lot with my Philips NMS-8250, and everything worked fine (the SD card format is the one I like most on both MSX and PC).

Lately, I mostly use a Panasonic FS-A1 (64 KB RAM and no disk) and I can't seem to use the SD Padial cartridge.

I have several questions.

MSX-DOS 1:
1) If the SD card plugged in the SD Padial contains the COMMAND.COM and MSXDOS.SYS of MSX-DOS 1, should the SD card be able to boot even on the FS-A1? (requirements seem fulfilled)
2) Or if not, should the SD card be formatted in FAT12?
3) If so, how?

MSX-DOS 2:
From what I understand, I'm missing 2 things to use MSX-DOS 2 on the FS-A1: The DISK-BASIC 2.0 ROM and at least 128 KB of memory.
4) Is that all it takes?
5) Can we find cartridges that combine these two elements (like the Japanese MSX-DOS 2 cartridges back in the day)? (I don't intend to use a complex and expensive cartridge like the C2 for this).
6) If I plug a FlashROM with DISK-BASIC + a RAM cartridge into a slot expander, should it work?

Thanks,

By sdsnatcher73

Enlighted (4288)

16-08-2023, 22:18

The issue is most likely just the lack of memory mapper. DOS1 should work but needs a FAT12 partition to boot from. Your NMS8250 also has no DISK ROM 2.0, the SD Padial (I don’t know the interface myself to be honest) most likely has a Nextor kernel (it may be a bit older version), but any Nextor or MSX-DOS2 will require a memory mapper of 128kB minimum. So all you need to add is a memory mapper cartridge in slot 2…

By gdx

Enlighted (6429)

17-08-2023, 01:56

aoineko wrote:

In recent years, I've been using my SD Padial (RIP) cartridge a lot with my Philips NMS-8250

RIP?

aoineko wrote:

Lately, I mostly use a Panasonic FS-A1 (64 KB RAM and no disk) and I can't seem to use the SD Padial cartridge.

What is your Padial SD? Do you have removed the FS-A1 firmware?

https://www.msx.org/wiki/Padial_SD_interfaces

By aoineko

Paragon (1134)

17-08-2023, 07:46

gdx wrote:

RIP?

Here

aoineko wrote:

What is your Padial SD? Do you have removed the FS-A1 firmxare?

Not sure of the exact model. The cartridge was sell in a box.
It was a new one bought about 4-5 years ago. There are significant changes between revisions?

And yes, I removed FS-A1 firmware.

By gdx

Enlighted (6429)

17-08-2023, 09:51

Can you take pictures to try to recognize it?

aoineko wrote:

And yes, I removed FS-A1 firmware.

So one less potential problem.

By aoineko

Paragon (1134)

05-09-2023, 22:55

I bought a Homer II 1024 KB memory cartridge but my SD Padial still don't boot on my Panasonic FS-A1 (I tried both slot 1 & 2 combination). SD Padial starts up without a hitch with the Philips NMS 8250 (without any other cartridge).

How do I know if the Homer II 1024 KB is working properly? My SCC+ SD MegaFlashROM won't boot either if the Homer II is inserted (it works fine on the FS-A1 without the Homer).

Any idea how to test that the Homer II 1024 KB cartridge works using BASIC?

EDIT: SD Padial start up on Panasonic FS-A1 with a MSX-DOS 1 disk. Are you sure a mamory mapper cartridge should be enough to start MSX-DOS 2 disk?

By aoineko

Paragon (1134)

06-09-2023, 09:08

It seems that the Homer II 1024 KB cartridge does not work well with the Panasonic FS-A1.
Do you know of a memory expansion cartridge that is compatible with the FS-A1?

By gdx

Enlighted (6429)

06-09-2023, 09:49

I recommend memory expansions that use SRAM. I use the Musical Memory Mapper on my FS-A1. It works well but it doesn't seem to be selling anymore.

By aoineko

Paragon (1134)

17-09-2023, 14:33

I did some new tests.

With TestRAM, I was able to check that my 1 MB Homer II memory-mapper cartridge works properly on my Philips NMS 8250.
My MSXgl "s_dos2" sample also detect and handle the Homer II properly.
The problem seems to be specific to the Panasonic FS-A1.

I managed to start the SD Padial on the Panasonic FS-A1 with an SD card containing MSX-DOS 1, so the problem is limited to MSX-DOS 2 and its need for a memory mapper.

Any idea why the Homer II cartridge won't work with the FS-A1?
It blocks the start-up of the SD Padial or MFR SCC+ SD.
I've tried flashing TestRAM on an MFR 512K cartridge, but the FS-A1 also freezes if the Homer II is inserted in the MSX (TestRAM ROM works fine without the Homer II).

gdx wrote:

I recommend memory expansions that use SRAM. I use the Musical Memory Mapper on my FS-A1. It works well but it doesn't seem to be selling anymore.

Why would it work better?
Do you know of a model I could buy?

EDIT: Does the FS-A1, which has no internal memory mapper, have the same problems as an MSX1? Or is the MSX2 BIOS supposed to handle mappers even if the MSX doesn't have one?

By gdx

Enlighted (6429)

18-09-2023, 10:27

aoineko wrote:

Any idea why the Homer II cartridge won't work with the FS-A1?

Hard to say without the circuit diagram. The RAM may be too fast, Signals are not connected correctly or the FS-A1 is not very tolerant of signals that are a little offset. It may also be the unused bits of the mapper that causes the problem.

aoineko wrote:

Why would it work better?

Because they're easier to make. No /RAS no /CAS signal and no risk of data loss during a CPU pause.

aoineko wrote:

Why would it work better?

If I remember well, the FS-A1 has an internal memory mapper register that works up to 1024kB but without effect on RAM.

By aoineko

Paragon (1134)

24-09-2023, 00:35

Just to let you know that I bought a Homer 1 512KB cartridge and that one works fine with the FS-A1. Apparently it's SRAM based so that would confirm the problem with the Homer II 1MB which is PSRAM based.

Now I can use the SD Padial in MSX-DOS 2 mode on my Panasonic FS-A1! \o/

However, I discovered an annoying little detail: the SD Padial warns the user of disk emulation changes by flashing the CAPS LED... except that the FS-A1 has no LED at all (apart from power-on).

I like the FS-A1's compact design, but the lack of LEDs or reset button make it not the most practical MSX.