SB BBC @ GBR Oldie hints/tips #144-148 Hints and tips from the archives of Wakefield BBC Micro User Group... 144. ADFS *COPY syntax ~~~~~~~~~~~~~~~~~ The *COPY syntax on the ADFS is different from that on the DFS, and is a bit obscure. You must specify the filename to be copied, including the directory and/or drive specification if they are not current, and then the directory and/or drive specification of the destination, (ie just the pathname). For example, suppose I want to copy a file called "Fred" from the current drive (0) and directory to the root directory on the other drive (1). This would be achieved with *COPY Fred :1 If I needed to include full pathnames, and I was copying from a sub-directory "NAMES" on drive 0 to a sub-directory "PEOPLE" on drive 1, then it might look something like *COPY :0.$.NAMES.Fred:1.$.PEOPLE . You can of course include the wildcard characters "#" and "*" in the filename if you are copying a group of files. You cannot change the filename when copying in this way, but you can by using the same syntax with *MOVE, and adding the new filename after the destination pathname. *MOVE also has the advantage that you can add -ADFS-, -DISC- etc at the beginning of the pathnames to copy between filing systems, but it has the disadvantage of being appallingly slow. For copying between filing systems, those of you with the Advanced Disc Toolkit are better off using *XFER instead, as it is far faster. 145. Plotting ellipses ~~~~~~~~~~~~~~~~~ By referring to the list of PLOT commands on page 232 of the Master Welcome guide, you can easily work out how to draw rectangles etc., using similar methods to drawing triangles. However, drawing ellipses is a bit more tricky. You must first 'visit' the dead centre of the ellipse, as you might expect. You must then visit the point where the ellipse cuts a horizontal line drawn through the centre. Since the Y-coordinate of this point is by definition the same as that of the centre, it doesn't matter what Y-coordinate you put in the MOVE, DRAW or PLOT command you use to visit the point, as the true value is assumed automatically. The horizontal line cuts the ellipse twice, but it doesn't matter which of the two points you choose. Finally, you should use the ellipse PLOT command, eg 197, to specify the highest point of the ellipse, ie the point with greatest Y-coordinate. (Alternatively, it can be the lowest point of the ellipse.) Anyone with access to the Acorn GXR manual should find no difficulty with the Master's extra PLOT commands, otherwise you need to see the Master Reference Manual part 1, which is at last available. 146. VDU terminator ~~~~~~~~~~~~~~ There is a new terminator for the VDU commands, which sends 9 zero bytes. Thus, VDU23,1,0;0;0;0; can be replaced with VDU23,1| . It doesn't matter if too many zeros are sent, as they will have no effect. 147. Character founts ~~~~~~~~~~~~~~~~ If you insert the ADFS Welcome disc and type *thin, *Italic or *7by8 , the screen ASCII character set is modified with interesting results in Modes 0 to 6; Cancel with *FX20 . For a comparison of all 3 of these founts, enter Mode 3, (but not Mode 131 or SHADOW modes), and type *LOAD LIBRARY.Fonts 4000 You can also modify some of the ASCII characters from 128 to 255, so try typing FORc%=128TO255:VDUc%,32:NEXT both before and after typing *EXEC LIBRARY.Pfont 148. ROM sockets ~~~~~~~~~~~ In addition to the two external cartridge sockets, which can support 4 ROMs, there are 3 spare internal ROM sockets. The only one which works initially is the centre one, (labelled IC27), and this corresponds to ROM slot 8. The rearmost socket, labelled IC37, corresponds to ROM slot 7, but this is normally configured as sideways RAM, (SRAM). To use if for a ROM, shift the nearby link LK19 to the right. The remaining socket at the front is labelled IC41, and corresponds to ROM slot 5, which is also normally configured as SRAM. To bring this into use, shift the nearby link LK18 to the right. Note that in gaining slot 7 as ROM, you lose SRAM slots 6 and 7. Similarly, in gaining ROM slot 5, you lose SRAM slots 4 and 5. This because each slot supports up to 16k, but ROMs can be from 8k up to 32k, and might need to occupy two slots. This means that you won't be able to run BAS128, which needs all 4 slots as SRAM. I've had Disc Doctor, Wordwise-Plus and Printmaster all happily installed and working. When the plug-in cartridges are used, slots 0 to 3 are available for ROMs, so there should be no need to sacrifice SRAM. 73 Rick G4BLT @ GB7WRG