Loading from Floppy (BBC Micro)

to load content from the floppy drive first connect the ide and power to the underside of the computer the bbc micro uses 5 1/4" floppy discs a great guide to using floppy discs is by cumana https //archbee doc uploads s3 amazonaws com/j28kvka0c jxcfzcoqq29 6npg6 miomliepvic8mo7 20250404 131105 pdf floppy discs can be formatted into 40 or 80 track for the bbc micro your floppy disc drive must support 40 or 80 track or read and write each time sometimes you get a unit that only reads 40 or 80 tracks, and others have a switch on the back to switch between 40 and 80 listing contents of floppy commands may vary depending on which version of dfs or adfs you are running type cat and press enter to list the contents of the floppy disc running floppy disc boot often floppy discs will have a !boot file this is designed to be run easily like executing a default exe on a computer to run the !boot file, press shift + break this will run the intended startup from the floppy disc if it has a boot file formatting disc to format a disc make sure to remove the write protect notch from the disc for the side you want to write on the discs are dual sided so there is a write protect notch for each side when looking at the disc with the exposed disc at the top, the notch on the left is for that side of the disc remove the tape/notch so it is writeable in this photo, this side of the disc is protected by the tape, but the other side (so the right side notch) being open means the other side is writeable depending on what roms you have installed in your micro, you might need to load up the format utility first type help to see what roms are loaded if you have dfs 1 20 for example it doesn't have the format utility however, dfs 2 2x has it built in but requires you to upgrade your micro with a 1770 kit replacing the 8271 disc interface chip with one that supports double density discs the dfs 2 2x checks if it detects the 1770 disc interface, if it does not it disables itself and doesn't show the master 128 model of micro had dfs 2 2x as default, the 1770 interface and so supports formatting out of the box the common way to format on a bbc micro b (not the master 128 or upgraded b models with 1770 interfaces) was to add a disc doctor rom to your rom sockets this come with the form command find attached the manual for disc doctor we will use this syntax as it is supported by all models of micro https //archbee doc uploads s3 amazonaws com/j28kvka0c jxcfzcoqq29 fkyoqx5ic6pn2z3jmcrj7 20250406 111727 pdf example syntax usage here formatting 40 track disc to format a 40 track disc, have the disc inserted with the write protect tab clear/removed and type the following form 0 40 this will format the drive 0 (default floppy drive), in 40 track mode if your disc is write protected it will fail at the first sector with format error to format as an 80 track disc make sure your floppy disc is setup in the 80t position or the drive is an 80t some drives are 40t or 80t only, others have switches to go between each mode form 0 80 listing files on disc to see what files are on the floppy disc simply type cat standing for catalogue this will list the contents of the disc here we can see files named !boot , ca , !help and so on the l after each name means it is a locked file that cannot be modified making floppy runable or executable notice in the image above the option 2 (run) by default, formatted floppy discs are option 0 to make the floppy runnable (meaning to call a command when you press shift + break ) you can set the floppy to one of these 4 modes by calling the opt command with specific numbers this then executes the specific command when you press shift + break opt 4,0 > no boot opt 4,1 > load !boot opt 4,2 > run !boot opt 4,3 > exec !boot i won't cover all these options here but you can then create a !boot file to be loaded, run or execute saving to & loading from disc firstly, write your program, then use the save "filename" command to save the program in memory to the floppy disc, called filename loading back is just as easy and overwrites the program in memory call load "filename" to load the filename from disc here is an example of making a new program, saving it to disc, clearing the program in memory and loading it back, then running it fault codes althought not always guaranteed, as the drive could be bad or disc bad in general, here is what the fault codes often mean error 08 (clock error) during a disc read operation a clock bit was missing error 0a (late dma) during a disc transfer the processor did not respond fast enough, most likely due to a faulty disc interface card error 0c (id field crc error) the cyclic redundancy check derived from the data read back differed from that stored on the disc error 0e (data crc error) the cyclic redundancy check derived form the data read back differed from that stored on the disc during a disc read error 10 (drive not ready) during a transfer the disc stopped rotating often caused by a badly inserted disc error 14 (track zero not found) controller failed to find track zero often an unformatted disc error 18 (sector not found) controller failed to find required sector either a corrupted or an unformatted disc this can also be an error with the floppy disc interface ic 8271 on micros, or 1770/1772 on master 128 models or upgraded micros