HELP NEEDED - BBC Master Compact & SD2BBC Not Working

[troupe86]

Hey all,

I'm a frequent enough lurker around these parts but a seldom poster. I posted on the Acorn enthusiasts group the other with regards to my BBC Master Compact. I picked it up for £20 locally and gave it a good clean up - I'm due to change the RIFA capacitors shortly on it too, but I digress.


I basically sought out a solution for playing games on my Master Compact and thefuturewas8bit's SD2BBC using the Smart SPI ROM seemed like the best option.

I bought the device along with a supplied SD card from thefuturewas8bit and it arrived in good time. I followed all of the instructions for installing it and prepping the SD card to a tee and switched it on. However, the screen (despite saying 'Smart SPI' onscreen) kept saying 'Card?'. Despite me using every conceivable command such as '*CONFIGURE FILE 8', '*CARD*', '*MENU' etc, I still couldn't get the card showing.

I sent an email to thefuturewas8bit who suggested using a different SD card, but even with a slower class SD card and nothing appears to be showing. I have the checked the board visually and there are no dry solder joints on the joystick adaptor so I doubt that's the cause of the issue. I've also taken out ROMS and replaced them again, and that still isn't fixing the issue. I don't think that thefuturewas8bit knows what's going wrong either.

So, to recap...

- Bought SD2BBC for my new Master Compact, but it's not working.
- Follow all of the installations instructions properly and format my SD card - still not working.
- Buy a new slower class SD card, format it and... still not working. New SD card actually locks my BBC Compact up and I cant use the keyboard. The SD2BBC has a solid red light on it when I use the newly purchased SD card.
- Reinstall the supplied SD card from thefuturewas8bit and it doesn't lock my Beeb up - still not working though.
- Take out Interbase and Viewsheet ROMS in case they were interfering. They weren't as it's still not working.
- Use *UNPLUG to cut out the ADFS in case it is interfering with Smart SPI - still not working.

Does anyone have an idea? I've supplied some photos below. I'm fairly novice when it comes to the Beeb so please bear with me... I'm ok with soldering a capacitor or two on hardware but I'm not au fait with the ins and outs of the Beeb.












Thanks!

[richardtoohey]

Probably not relevant to what you are doing, but when I've had Card? messages that nothing seemed to fix, it seemed to be down to a faulty 6522. But that was a BBC B and not Smart SPI etc.

[Ramtop]

May be a good idea to speak to the supplier of the SD interface and ask if they can take it back and test it. Although it does sound like you might have a bad 6522 VIA, which is not trivial to fix as it's soldered in place.

[1024MAK]

Before jumping the gun, my suggestion would be to test the I/O lines used by this device (and provided by the 6522 VIA).

Does a joystick work okay?
Does a mouse work okay (these also plug into the same joystick port, you will need to load some appropriate software)?

Mark

[troupe86]

Before jumping the gun, my suggestion would be to test the I/O lines used by this device (and provided by the 6522 VIA).

Does a joystick work okay?
Does a mouse work okay (these also plug into the same joystick port, you will need to load some appropriate software)?

Mark

Unfortunately I don't have any software to test it. I'd probably need to come up with some form of BASIC program to get it tested. Is there a ready-made program to test joysticks?

The chap behind thefuturewas8bit also contacted me back this morning and he seems to think that it's something in the Compact which is causing the problem. I'm so close to getting rid of it at the moment as I've wasted so many evenings trying everything I feasibly can to get it working.

As for replacing the 6522, that's not socketed as far as I can remember and I wouldn't fancy desoldering it as I don't have a dedicated vacuum soldering station.

[danielj]

Hello - I replied on facebook. Everything points at the 6522. I've not personally seen any Master Compact joystick test routines - you'd have to write something. If that sounds like too much effort, and you don't have a desoldering station, if you're willing to sacrifice the potentially faulty 6522 just use side cutters to snip off the legs, then desolder the legs one by one, clear out the holes and solder in a socket and plop in a new 6522. Of course there's always the possibility that won't fix it :/ - but it's also possible that it'll look like the joystick works OK and the sd card doesn't so you won't be any the wiser (they're using the 6522 in different ways)

d.

[1024MAK]

Funny that you should mention a BASIC test program... see here for a BASIC program to test the user port (which on a Compact, is the joystick port).

Somewhere on the forum there is some links to help with testing a mouse...

Mark

[danielj]

Funny that you should mention a BASIC test program... see here for a BASIC program to test the user port (which on a Compact, is the joystick port).

Somewhere on the forum there is some links to help with testing a mouse...

Ah, there we go

d.

[troupe86]

Funny that you should mention a BASIC test program... see here for a BASIC program to test the user port (which on a Compact, is the joystick port).

Somewhere on the forum there is some links to help with testing a mouse...

Mark

Please excuse my ignorance, but I should be fine just plugging a joystick in and moving it to check inputs against that BASIC program, right? I don't fancy rigging up a Frankenstein experiment. Besides, I don't have any spare wires to hand.

[troupe86]

Hmm, there seems to be a problem with that BASIC input test program...

I can't seem to access the ~ key properly. It comes out as a division symbol. After going through the symbol shift on my Compact keyboard, some of the symbols come out differently; for example, the { [ key comes out as '1/4'.

Unsurprisngly, there's a fault when I try to run the BASIC program as it claims 'No such variable at line 30', due to the wrong symbol.

[Kazzie]

Hmm, there seems to be a problem with that BASIC input test program...

I can't seem to access the ~ key properly. It comes out as a division symbol. After going through the symbol shift on my Compact keyboard, some of the symbols come out differently; for example, the { [ key comes out as '1/4'.

Unsurprisngly, there's a fault when I try to run the BASIC program as it claims 'No such variable at line 30', due to the wrong symbol.

That'll be because Mode 7 displays the Teletext character set, which has a few characters that are different to ASCII. The characters are stored correctly in the machine, they just look a bit odd. You can either carry on regardless, or switch to one of Modes 1-6 to see the ~ as intended.

[troupe86]

Hmm, there seems to be a problem with that BASIC input test program...

I can't seem to access the ~ key properly. It comes out as a division symbol. After going through the symbol shift on my Compact keyboard, some of the symbols come out differently; for example, the { [ key comes out as '1/4'.

Unsurprisngly, there's a fault when I try to run the BASIC program as it claims 'No such variable at line 30', due to the wrong symbol.

That'll be because Mode 7 displays the Teletext character set, which has a few characters that are different to ASCII. The characters are stored correctly in the machine, they just look a bit odd. You can either carry on regardless, or switch to one of Modes 1-6 to see the ~ as intended.

It definitely won't run the program because the wrong character has been entered into the BASIC program. Any idea how to switch Modes to see if it fixes it? Thanks!

[danielj]

Just type "MODE 6" and LIST to see what you'd entered

d.

[CMcDougall]

just do this for 33p , worked on mine
viewtopic.php?f=3&t=6001&p=83100&hilit= ... PSU#p83100

[troupe86]

Ok, so changing the mode to mode 6 definitely worked with regards to getting the BASIC program typed in.

I ran the program and the joystick movement indicated input as follows:

Resting (centre) - FF
Up - F7
Down - FB
Left - FD
Right - EF
Button - FE

However, I noticed that there was a weird pulsing interference under the characters (see picture):

Interference around characters.

And when I hit break, I noticed this error come up on screen 'Bad sum on channel 3':

'Bad sum on channel 3'

Any idea what the problem could be based on these new findings? It seems to be that I keep going down dead ends in trying to find out what is wrong with the computer. I just want to play some games from my SD card.

By the way, thanks everyone for your help thus far!

[troupe86]

just do this for 33p , worked on mine
viewtopic.php?f=3&t=6001&p=83100&hilit= ... PSU#p83100

Haha! That looks pretty great! Did you not need an internal ROM chip as well?

[1024MAK]

I can’t see your pictures/photos. Why not use the attachment button below the text entry/edit box to upload them to the forum?

Mark

[troupe86]

I can’t see your pictures/photos. Why not use the attachment button below the text entry/edit box to upload them to the forum?

Mark

Aha! Fixed it!

[1024MAK]

So those results show that all the 6522 VIA pins used to detect inputs on the joystick port, from a joystick, are working correctly. However, this is not a full test. There are two other input pins (CB1 on pin 5 and CB2 on pin 9), plus you can’t test if the system can output valid logic levels using an input only device like a joystick. The probability is that the 6522 VIA chip is okay, as in most cases they either are fine or go completely bad. But we currently can’t eliminate this as the problem

For reference, the pin-out of the joystick port can be found in this document.

However, I noticed that there was a weird pulsing interference under the characters (see picture):

That will be the curser being constantly moved. Unless an instruction is issued telling the OS to turn it off, wherever the current print position is on screen, it will print a curser. But when the print position keeps moving, you get this affect. That’s normal, so no need to worry about it.

And when I hit break, I noticed this error come up on screen 'Bad sum on channel 3':

Not sure what’s going on here. But if the Smart SPI ROM does not like what the test program did, it may have have got confused. Is everything normal if you use [CONTROL-BREAK] or if you switch off, then switch back on?

Any idea what the problem could be based on these new findings? It seems to be that I keep going down dead ends in trying to find out what is wrong with the computer. I just want to play some games from my SD card.

Well, the testing so far is indicating that the Master Compact is likely okay (but keep in mind what I say above). You have tried two different cards and got different results. It’s unlikely the device itself is faulty if it is brand new, but that is still a possibility. So although we are slightly further forward, we don’t seem to have worked out what the problem is yet.

Ideally, it would be good if the SD2BBC could be tested on another machine.

Mark

[troupe86]

So those results show that all the 6522 VIA pins used to detect inputs on the joystick port, from a joystick, are working correctly. However, this is not a full test. There are two other input pins (CB1 on pin 5 and CB2 on pin 9), plus you can’t test if the system can output valid logic levels using an input only device like a joystick. The probability is that the 6522 VIA chip is okay, as in most cases they either are fine or go completely bad. But we currently can’t eliminate this as the problem

For reference, the pin-out of the joystick port can be found in this document.

However, I noticed that there was a weird pulsing interference under the characters (see picture):

That will be the curser being constantly moved. Unless an instruction is issued telling the OS to turn it off, wherever the current print position is on screen, it will print a curser. But when the print position keeps moving, you get this affect. That’s normal, so no need to worry about it.

And when I hit break, I noticed this error come up on screen 'Bad sum on channel 3':

Not sure what’s going on here. But if the Smart SPI ROM does not like what the test program did, it may have have got confused. Is everything normal if you use [CONTROL-BREAK] or if you switch off, then switch back on?

Any idea what the problem could be based on these new findings? It seems to be that I keep going down dead ends in trying to find out what is wrong with the computer. I just want to play some games from my SD card.

Well, the testing so far is indicating that the Master Compact is likely okay (but keep in mind what I say above). You have tried two different cards and got different results. It’s unlikely the device itself is faulty if it is brand new, but that is still a possibility. So although we are slightly further forward, we don’t seem to have worked out what the problem is yet.

Ideally, it would be good if the SD2BBC could be tested on another machine.

Mark

Thanks for the reply! I'll be honest, I was getting the 'Bad sum on channel 3' message the odd time ever since I tampered with the ROM chips internally. I might have reseated them in the wrong sockets again. The SmartSPI is definitely in the correct socket though. The message sometimes shows up when booting the machine, but normally disappears after a couple of repeated boot cycles.

Unfortunately I don't have another Master Compact to test the SD2BBC and SD card in. If someone else has one, and is willing to test the SD2BBC along with the SD card for me, I could post it to them and pay for return postage too.

[CMcDougall]

ehhh, where did my post go about : bad sum err3 is dumb ADFS looking for a boot disc, it's not IBMBIOS / IBMDOS.com
+ don't throw it out, as I don't have a spare Mcompact
I could try your overpriced 33p board if you wish, mine is at hand at moment as bedroom is half decorated, no carpet shops
Just send a PM & will reply.....

[troupe86]

ehhh, where did my post go about : bad sum err3 is dumb ADFS looking for a boot disc, it's not IBMBIOS / IBMDOS.com
+ don't throw it out, as I don't have a spare Mcompact
I could try your overpriced 33p board if you wish, mine is at hand at moment as bedroom is half decorated, no carpet shops
Just send a PM & will reply.....

Typical... I go to send a PM but I don't have the board privileges to do so yet.

It seems to be one stumbling block after another. Hah! If you are on Facebook at all, please send me a PM there. My name is Richard Troupe and I'm a member of the Acorn Computer Enthusiast group.

[CMcDougall]

found & PMd :

[troupe86]

I can't believe I've only just noticed this now, but it seems like one of the joystick port pins has been pushed in a bit too far. I looked over the joystick port etc and I honestly didn't notice it before. The only explanation for missing it is that I've been extremely busy and stressed whilst working from home.

I wonder if this is what is causing my issues?

I ran that BASIC program and the joystick seemed to respond OK, but I wonder if that particular pin that has been pushed in is used for data reading and transfer with the SD2BBC device?

[CMcDougall]

looking at the diagram I linked to before, that's pin8 which is 0/gnd, so long nose pliers, pull it out to same length as rest, then should work !!

[DutchAcorn]

Also have a good look at the female plug, it may be the cause of the pushed back pin.