Master ADFS problems

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jubber
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Master ADFS problems

Postby jubber » Fri Nov 10, 2017 2:36 pm

Hi - I've just bought a BBC Master, and it seems to be in pretty good condition. Needed to desolder a cursor key, and two of the rom sockets don't work, but MMFS and a new battery seem to fix everything else. I can even play Dunjunz using some Cumana drives and DFS.

However, I got hold of a Welcome disk for the machine, which claims to be ADFS - and that I can't read. I can switch to ADFS (Ctrl-A Break) and *. will show the directory - but any attempt to CHAIN"$.Clown" for instance will report Error 50.

Might this mean I simply need to clean the disk drive? It works for DFS disks, but perhaps the extra density is an issue. Or maybe those Cumana drives can't handle ADFS, although *. working is encouraging. It could also be that I simply don't know the correct procedure for using ADFS. I'm not even sure how to check the second drive - *DRIVE 1,2 or 3 doesn't make the second drive light come on with *.

Any advice much appreciated.

Robin

crj
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Re: Master ADFS problems

Postby crj » Fri Nov 10, 2017 4:08 pm

When you say two of the ROM sockets don't work, are you aware that you must move LK18 west to use socket IC41 and LK19 to use IC37? By default, banks 4-7 are sideways RAM.

As for the floppy drive problem, have you got any other ADFS discs you can try? Instinctively, it feels unlikely that a head cleanliness problem would affect ADFS but not DFS. Unfortunately, it may be that the Welcome disc has just aged badly. /-8

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CMcDougall
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Re: Master ADFS problems

Postby CMcDougall » Fri Nov 10, 2017 5:35 pm

ADFS is a problem :x :lol:

to do *Drive 0/1/2/3 it is *MOUNT 1 to get Drive1, try your disc in other drive for your Clown game, but doubt it as it loads ok....
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jubber
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Re: Master ADFS problems

Postby jubber » Fri Nov 10, 2017 6:23 pm

Two great hints - thanks guys!

I'll try *MOUNT 1 on the other drive.

I also didn't know about the rom socket link. I did see those link pins when adding mmfs to the machine, and briefly wondered what they were for. If I set them so that the two rom sockets work - does this turn my Master 128 into a Master 64 (for want of a better description)? Will the few games that use shadow ram still be able to access what is left?

Cheers,

Robin

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danielj
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Re: Master ADFS problems

Postby danielj » Fri Nov 10, 2017 6:49 pm

Yup, setting the links will remove your sideways ram. I'd leave them intact - as you rightly say, you don't want to end up with a Master 64 :) The preferred solution with the master is to use a rom cartridge.

d.

jubber
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Re: Master ADFS problems

Postby jubber » Fri Nov 10, 2017 7:23 pm

I'm guessing nobody makes master cartridges any more - so if I want to add roms to the Master, I'd need some sort of circuit board with a rom socket on it. I can burn eeproms, but what I know about electronic circuitry would fill the world's smallest manual.

Peering inside the Master's cartridge slots I can see 22 connectors in a line. Roms use 28 pins, so I'm not sure how the two things are meant to interface together.

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danielj
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Re: Master ADFS problems

Postby danielj » Fri Nov 10, 2017 7:34 pm

There are 22 on each side iirc - 44 in total :) - http://chrisacorns.computinghistory.org ... AN/014.pdf
You can get one of these from Dave: viewtopic.php?f=3&t=5555&p=51496
Or one of these: viewtopic.php?f=3&t=5672&p=52685

ROM cartridge will allow you to plop ROMs in, battery backed RAM will let you load your own from disc and they'll stay (due to battery). There are other solutions, but these are probably the easiest two in the first instance :)

d.

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BeebMaster
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Re: Master ADFS problems

Postby BeebMaster » Fri Nov 10, 2017 9:11 pm

Is it possible you have a single-sided disc drive? An 80-track Master 128 Welcome disc has all the data on the "second" side of the disc which can't be read by a single sided drive. The 40-track version uses the "first" side. It's the same disc, but there is a utility on the disc which allows you to change between the two which works by pointing the catalogue entries to a different locations for 40 and 80 track.
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daveejhitchins
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Re: Master ADFS problems

Postby daveejhitchins » Sat Nov 11, 2017 10:33 am

CMcDougall wrote:ADFS is a problem :x :lol:

to do *Drive 0/1/2/3 it is *MOUNT 1 to get Drive1, try your disc in other drive for your Clown game, but doubt it as it loads ok....
Col. I believe this is your tamest post with "ADFS" within it . . . =D> :lol:

Dave H :D
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jubber
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Re: Master ADFS problems

Postby jubber » Sat Nov 11, 2017 11:26 am

I'm not sure how to tell if the drive is single sided. It has CUMANA written on the front, and a couple of switches at the back that can change between 40 and 80 track modes.

I'm mainly after the setup utility - so I may try and copy that onto BEEB.MMC, and leave ADFS in the past, where it belongs. The disk size is nice, but it doesn't even contain a format command on the rom - which is a real blunder imo

crj
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Re: Master ADFS problems

Postby crj » Sat Nov 11, 2017 2:12 pm

jubber wrote:I'm not sure how to tell if the drive is single sided. It has CUMANA written on the front, and a couple of switches at the back that can change between 40 and 80 track modes.

With DFS, try to use drives 2/3. Those are the flip sides of drives 0/1 in DFS.

Meanwhile, if you have a 40/80 switch, try the Welcome disc with it in the other position.

crj
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Re: Master ADFS problems

Postby crj » Sat Nov 11, 2017 2:16 pm

BeebMaster wrote:Is it possible you have a single-sided disc drive? An 80-track Master 128 Welcome disc has all the data on the "second" side of the disc which can't be read by a single sided drive. The 40-track version uses the "first" side. It's the same disc, but there is a utility on the disc which allows you to change between the two which works by pointing the catalogue entries to a different locations for 40 and 80 track.

Good call! That rings a bell.

I mis-remembered the Welcome disc as simultaneously supporting 40-track and 80-track. (Which isn't impossible, read-only, if you sacrifice some storage space and get cunning with the layout.) If it was flipped between 40-track and 160-track by writing a new track 0, that does change matters...

jubber
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Re: Master ADFS problems

Postby jubber » Sun Nov 12, 2017 12:51 am

Hah! Finally, I've worked it out - many thanks for all your replies. The left hand 40/80 switch affects the right hand drive, and vice versa. This also explains why drive 1 was lighting up when *drive 0 was used, and vice versa. Somewhere inside the Cumana double disk drive, somebody presumably made a slight error in the wiring.

Thanks again for all the suggestions - they pointed me in the right direction!


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