BBC Master 128 MMFS Card?

[peterb999]

Hi all,

It's been a couple of years since I last used my BBC Master. I have a MMFS card which worked fine when I last used it.

However, when I turn it on now and use *. I get an error message saying Card?

I've tried different SD cards and made sure they are formatted in FAT32 and got the BEEB.MMB file in the root of the card but still get the error.

Any ideas?

Thanks

[geraldholdsworth]

Faulty VIA chip?

I've got a Master that does the same, but the interface works fine on my other Master. Haven't got a chance to swap the chip yet - a job still to do.

[peterb999]

Thanks for the reply.

My Master has the has the triple OS switch and it wouldn't work on any of them. However, I tried typing *CARD in all three and it worked in one of the modes and I could read from the Micro SD card again.

Think I need to read up a lot and fully understand how it all works.

[geraldholdsworth]

That rules out the VIA chip then, which is good.

There are different versions of MMFS for different machines. I'm assuming that the one it works on is the Master OS, while the other two are BBC OSes?

What I've done is to source another flash ROM, and put MMFS into both versions on my OS switcher (I'm only going from 3.2 to 3.5).

From the text file at https://github.com/hoglet67/MMFS/releases:

MMFS Model B/B+: normal ROM version of MMFS (PAGE=&1900)
MMFSDBG Model B/B+: - with extra logging enabled (PAGE=&1900)
MMFS2 Model B/B+: - for a second user port at &FE80 (PAGE=&1900)
MMFS3 Model B/B+: - for a second user port at &FEA0 (PAGE=&1900)
SWMMFS Model B/B+: - uses sideways RAM as workspace (PAGE=&0E00)
SWMMFS2 Model B/B+: - for a second user port at &FE80 (PAGE=&0E00)
ZMMFS Modem B/B+: - ROM bootloader into sideways RAM (PAGE=&0E00)

SWMMFS+ Model B+only: uses 12K of private workspace (PAGE=&0E00)

MAMMFS Master: normal ROM version of MMFS (PAGE=&0E00)
MAMMFS2 Master: - for a second user port at &FE80 (PAGE=&0E00)
MAMMFS3 Master: - for a second user port at &FEA0 (PAGE=&0E00)

EMMFS Electron: normal ROM version of MMFS (PAGE=&1900)
EMMFSDB Electron: - with extra logging enabled (PAGE=&1900)
ESWMMFS Electron: - uses sideways RAM as workspace (PAGE=&0E00)
ZEMMFS Electron: - ROM bootloader into sideways RAM (PAGE=&0E00)

[tricky]

Did your CMOS lose its settings?
I'm not sure if this can cause card?

[Ukwebb]

However, I tried typing *CARD in all three and it worked in one of the modes and I could read from the Micro SD card again.

Pretty certain the ROM itself is only suitable for one model of BBC, either BBCB or MASTER - So it should work in one of the mode settings - remember to power off when you change that switch too otherwise it wont properly take effect

[peterb999]

Many thanks for all the replies.

My MMFS ROM is for the Master so I guess this is why it doesn't work on the OS1.2 version.

My multirom is V2.0, V3.5 and V1.2. I'd have thought it would have worked on the V2.0 as well, but it doesn't

If I bought another ROM from ebay specifically for the BBC Model B and input it into one of the spare ROM slots would this mean that it would work on all the 3 different versions of OS?

I could have sworn that the chip used to work in V1.2 mode, but my memory is not what it once was, haha.

[Ukwebb]

The os.2.0 is what what the B+ and 1.2 is what was the BBC B

If you were to put in the model B and Master roms in together they would conflict. you would need to remove one for the other depending upon your OS switch. not ideal

[tricky]

You might be able to do something automated with SmartSPI as the same version works in all beebs, but doesn't have all of the features of mmfs and has a big that stops it writing correctly to some cards. Maybe it could load a program to auto detect the OS and load the appropriate mmfs into sideways ram before disabling smart spi and selecting mmfs.

PS on a Master, a gotek is a good option, but I don't know what happens with different filling systems then.

[Coeus]

My MMFS ROM is for the Master so I guess this is why it doesn't work on the OS1.2 version.

As far as I know, the reason for a Master specific version is not because of a difference in the hardware to access the card as I believe the VIA is at the same address. The difference is that the Master has some high workspace called HAZEL that allows the native Master filing systems to avoid taking up normal user memory. That is how it is possible to have PAGE (OSHWM) at &0E00 with discs (either DFS or ADFS). The Master version of MMFS is written to take advantage of this high workspace too so PAGE can be &0E00 with MMFS but the way the DFS code on which MMFS is based is written, a particular version has to be assembled for high workspace or low workspace - it can't dynamically adapt.

Then, when running on OS 1.20 or even OS 2.00, the HAZEL workspace is not enabled by default so the Master version of MMFS will find anything it tries to store in its workspace is not remembered and it won't work properly. It is hard to work around this because, when running under MOS 3.20 or MOS 3.50 the HAZEL workspace is normally accessible except when the VDU drivers are used, when it is paged out and VDU code executes from the same range of addresses. So the filing systems don't have code to page in the HAZEL workspace as required.

The solution I have adopted on my Master is to do as Gerald did and re-program the ROM on the multi-os so MMFS is one of the ROMs in the set that gets switched when you change OS. That means I can have a Master version of MMFS in the two Master OS banks (MOS 3.20 and MOS 3.50) and a BBC B version of MMFS in the OS 1.20 bank. For the OS 1.20 bank you can put it where you like. For the Master banks I have put mine in place of View, though that requires a little messing about - MMFS is not the full 16K and the View ROM has some OS at the end of it (either code or relocation tables) so you have to merge the two to make a new ROM image for that bank. The easier ones to replace are ViewSheet and EDIT.

See https://mdfs.net/Info/Comp/BBC/SROMs/MegaROM.htm for the layout of the Master MegaROM.