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The latest version of this code is always at http://sweh.spuddy.org/Beeb/TubeHost/ This is a Unix TubeHost filesystem written in perl based around JGH's HostFS concept http://mdfs.net/Software/Tube/Serial/ http://mdfs.net/Software/Tube/Serial/HostFS.txt In this model, the HostFS ROM makes "Tube" like communication but using the RS423 serial port instead. Since RS423 is a single channel in each directions, commands are embedded in the datastream. Essentially the HostFS passes standard BBC calls (eg OSBGET, OSARGS, OSFSC) and data structures across the channel, and all the complicated processing is performed on the remote server (aka TubeHost or Host, for short). Now this design (whilst slightly idiosyncratic - eg in how file data is transferred) is very clever and flexible. Ultimately it's up to the Host as to how to present a filesystem. *COMMANDS are also interpreted by the Host. In JGH's reference code he has a BASIC TubeHost server (and a precompiled Windows .exe from it). This has an ADFS look and feel; it's a hierarchical filesystem, with *DIR enter subdirectories, and "." as the directory separator and so on. His code translates Host<->Beeb filenames and presents them in a form native to the Beeb. I took a more DFS-like approach, taking ideas from MMB structures. In my system we have a single level tree (eg $HOME/Beeb_Disks). Each Unix subdirectory becomes an available disk which can be "inserted" into a drive (using the *DIN) command. There are 10 drives available (0->9). If the Unix directory is numbered then we assign this disk to a slot of that number; any unnumbered directories are assigned sequential numbers So, for example, on Unix: % ls Beeb_Disks 0.Mr_Ee 1.test1 10.test10 TAPES We would see this on the Beeb: >*DCAT Disks available: 0: 0.Mr_Ee 1: 1.test1 10: 10.test10 11: TAPES "TAPES" was assigned "11" because it was the next free slot. The rationale behind this structure was to make SSDs easier to handle. Using MMB_utils ( http://sweh.spuddy.org/Beeb/mmb_utils.html ) we could extract the contents of an SSD into a directory and now it shows up on the Beeb exactly as it should. % cd Beeb_Disks % beeb getfile ~/Cylon_Attack.ssd Cylon_Attack Saving $.Ca as Ca Saving $.Cylon as Cylon Saving $.!BOOT as !BOOT % ls Cylon_Attack !BOOT !BOOT.inf Ca Ca.inf Cylon Cylon.inf And now: >*DCAT Disks available: 0: 0.Mr_Ee 1: 1.test1 10: 10.test10 11: Cylon_Attack 12: TAPES >*DIN 5 Cylon_Attack >REM could also have done *DIN 5 11 'cos the assigned number was 11 >*I. :5.*.* $.Cylon L FF1900 FF8023 00237E $.Ca L 001100 00257D 004900 $.!BOOT 000000 000000 000025 >*DRIVE 5 >*TYPE !BOOT 10CLOSE#0 20*FX21 30CHAIN"CYLON" RUN > We can see the load/exec/locked attributes have been mainted, due to the INF files (which should be bbcim compatible). When TubeHost starts up, any disks with numbers 0->9 are pre-loaded into slots 0->9. You can see the current disks loaded: >*HSTATUS D Disk 0: 0.Mr_Ee Disk 1: 1.test1 Disk 2: Disk 3: Disk 4: Disk 5: Cylon_Attack Disk 6: Disk 7: Disk 8: Disk 9: Current drive: 5 Current directory: $ (:5:$) Current library: :0.$ Functions handled ================= 0x0C => 'OSARGS', Y=0, A=0 return current filesystem in A (Also handled in HOSTFS ROM) Y=0, A=1 return rest of command line (Handled in HOSTFS ROM) Y=0, A=255 sync all open files Y!=0, A=0 Get PTR# Y!=0, A=1 Set PTR# Y!=0, A=2 Read length (EXT#) Y!=0, A=3 Set length (EXT#) [ see note ] Y!=0, A=255 Sync this file 0x0E => 'OSBGET', Y=filehandle, read byte from file into A, C set if EOF before read occured 0x10 => 'OSBPUT', Y=filehandle, write byte from A into file 0x12 => 'OSFIND', A=0, close file Y A=40, openin A=80, openout A=C0, openup 0x14 => 'OSFILE', 00 SAVE 01 rewrite load/exec/attr 02 rewrite load 03 rewrite exec 04 rewrite attr 05 read catalog entry 06 Delete 07 Create empty file of defined size FF LOAD 0x16 => 'OSGBPB', A=1 write bytes to new ptr A=2 write bytes to current ptr A=3 get bytes from new ptr A=4 get bytes from current ptr A=5 Read disks title, boot opts A=6 read directory name A=7 read library name A=8 read files from directory 0x18 => 'OSFSC', 00 *OPT [ see note ] 01 CheckEOF 02 */ 03 *command 04 *RUN 05 *CAT 06 New filesystem (handled by HOSTFS ROM) 07 Handles (handled by HOSTFS ROM? Done here as 0x80-0x9F just in case) 08 *command alert (dropped by HOSTFS ROM) 09 *EX 0A *INFO 0B *RUN for library [ see note ] COMMENTS ========= OSARGS Y!=0, A=3 Set length (EXT#) - Neither B nor Master support this; the code is there but I dunno if it'll work OSFILE 07 Create empty file of defined size - appears to work. OSFSC 00 *OPT - "*OPT 5" sets debug level on host. "*OPT 6" sets speed delays (see below) No other *OPT value does anything 0B *RUN for library - not sure how to verify this one works! OSGBPB A=5 Read disks title, boot opts - disk name truncated to 12 chars if necessary A=8 read files from directory - This appears to work. Note that Unix filenames may be long and BBC programs may expect 7 or 10 character limits; not a bug in TubeHost but in Beeb programs A full Tube Host should also handle other types of calls (eg OSRDCHIO). These are not handled by this program; we are a pure filesystem server and not a generic Host application. Calls *NOT* handled: 0x00 => 'OSRDCHIO', 0x02 => 'OSCLI', 0x04 => 'OSBYTELO', 0x06 => 'OSBYTEHI', 0x08 => 'OSWORD', 0x0A => 'OSWORD0', *COMMANDS ========= can be prefixed with a ! if a ROM or OS commands conflicts *HSTATUS [DF] Displays status of Host, including what disks are in what slots, current directory/library status, and what files are currently open. "D" limits to disks/directories; "F" limits to open files *DCAT Shows what disks (Unix subdirectories) are available *DCREATE diskname Creates a new Unix subdirectory *DIN drive disk Inserts "disk" into drive *DOUT drive Ejects "disk" from drive *DRIVE drive *DIR dir As per DFS *HRESET Causes TubeHost to re-exec itself, which effectively resets it to startup mode (default disks, default directories, no open files etc) *INFO filespec *DELETE file *RENAME file1 file2 *ACCESS file [L] As per DFS *DMP file Test emulation of *DUMP performed on Host side *FOO count Debug command; sends "count" number of X's to the screen Running ======= This is pure perl code. To talk to a serial port you need the Device::SerialPort module. I'm not sure if I'm making any hard assumptions around Unix/Linux so this may work on other platforms. ./TubeHost [-s|-u] device [speed] "-s" ==> serial device (default) "-u" ==> Unix domain socket device ==> filename to connect to speed ==> Baud rate (only for serial; 9600 default). "Unix domain socket" is for VirtualBox users and BeebEm. It's possible to configure VirtualBox so the client OS (Windows, for example) has its serial port mapped to a Unix domain socket. Then BeebEm can connect its serial port to the client OS serial port. In this way TubeHost can talk to HostFS inside BeebEm inside Virtualbox. It's how I did my debugging! *OPT6 ===== Now HostFS and TubeHost is totally reliant on a clean serial channel. I've found, in testing, that sending data too quickly can cause characters to be lost, and thus corruption. I've seen this with both real serial ports and the VirtualBox emulated serial port. It's unclear if the issue is in HostFS or in my serial cable and the Linux/Virtualbox serial emulation. To work around this the serial send routines have delays built into them; after "A" characters have been sent, delay for "B" microseconds. The default is "A=1,B=1", which causes a 1ms delay after each character sent. Throughput on a 9600 baud connection works out around 720cps. Not as fast as floppy, but a lot faster than tape :-) These values can be tuned with "*OPT6". Convert AB into hex; &AB (or A*16+B) and pass to *OPT6. So the default is, effectively, *OPT6 17. If you are finding communication issues you can use *OPT6 and "*FOO" to help tune these timings. Once you have good values then you can, of course, hard code them into the script.