MMFS2 troubleshooting

[andrewh]

I have a Model B which has had no end of problems. However, I did have MMFS2 working on it a few weeks ago.

Now the computer has been repaired, I cannot get MMFS2 working. At power on, I get:

BBC Computer 32K
Model B MMFS2 Turbo
Card?

It does not respond to anything other than BREAK, when the last line changes to "BASIC" and all is well. However, *DCAT no longer works and just says "Card?". *DABOUT reports version 1.55.

Embarrassingly I can't remember which way the board plugs into the user port, but it doesn't make any difference. Have I broken it by putting it in the wrong way? Or is there something else going on?

[james]

Embarrassingly I can't remember which way the board plugs into the user port, but it doesn't make any difference. Have I broken it by putting it in the wrong way? Or is there something else going on?

That's what I did to mine. Plugged it in the wrong way round and it never worked again.

[andrewh]

Oops. Which way would have been the right way? I have failed to Google this repeatedly.

[vanekp]

which MMFS are you using, a photo may be handy to know which way it should go in and which MMFS we are talking about.

[itsmeedoofer]

Hey,

First post here, please be gentle

As part of the repair, you didn't have the user via replaced did you, ic69 ?

Just had a similar issue, back from repair, TurboSPI didn't work, just got card?

Turns out the 6522 thats was used in the repair (probably) had the shift register bug. I swapped the system via, ic3 with this one and it started working...

Just a thought....

Doofer

[Wheel_nut]

Embarrassingly I can't remember which way the board plugs into the user port, but it doesn't make any difference. Have I broken it by putting it in the wrong way? Or is there something else going on?

If you are using an IFEL Turbo adapter, it is impossible to insert the adapter incorrectly because the Connector is keyed to the socket,

A picture of the adapter would help diagnose your problem though I agree with Doofer's suggestion that it may be the 6522 Shift Register problem.

Robin

[andrewh]

Here is the card:

The connector is not keyed.

It's possible IC69 was replaced, I honestly cannot remember. The two 6522s are identical so I don't think there's much point swapping them and I don't have a spare. Is there any way I can find out if they have the bug?

[itsmeedoofer]

Hi,

Just for reference this 6522 had the SR bug.

And this one didn't

[Wheel_nut]

Here is the card: IMG_3463.jpegIMG_3460.jpeg

The connector is not keyed.

Hmmmmm.... That is not an IFEL Board and to my knowledge, only the IFEL Board uses Turbo so check whether you should be using the MMFSv2 TURBO ROM. That would account for the Card? error that you are seeing.

- Robin

[james]

Your photo appears to suggest the board itself says you need the U version of MMFS (though it’s not clear): https://github.com/hoglet67/MMFS/wiki/Release-structure

The second level of the folder structure has several entries, one per interface type:

U - Standard User Port (&FE60 on the Model B/Master or &FCB0 on the Electron) - Non-Turbo interface

But in your first post:

BBC Computer 32K
Model B MMFS2 Turbo
Card?

There’s also an earlier thread which mentions SD a card formats for this interface https://www.stardot.org.uk/forums/viewtopic.php?t=26058

[andrewh]

Ha, that's unfortunate. As part of the repair I was also given the Turbo ROM. If I use the correct ROM (that I had working with this card a few weeks ago) then I get:

BBC Computer 32K
Model B MMFS2
Card?

So same effect.

This is my 6522:

[vanekp]

from what you where saying you may have plug it in upside-down and damaged it at this point which would explain the non working MMFS, as you say the ROM is the one that worked with it before and I assume the SD card is also the same one that worked with it before and take it the SD card is still good.

[andrewh]

I bought a new interface and all is now well. This one I cannot insert the wrong way round!

Is it expected that filenames in *DCAT appear as the old DOS 8.3 format, eg ELITEA÷1.SSD instead of the full name?