Q: Ever since I moved up from my old Amstrad 1512 to a 386 I have been annoyed by the way Num Lock comes on when the PC is started up or re-booted. I still use the numeric keypad in preference to the additional cursor key block. Is there any way Num Lock can be turned off automatically?

A: As far as I know, not even the latest version of DOS allows you to set the state of Num Lock on start-up. However, there is a short program you can create which, when run from AUTOEXEC.BAT, turns Num Lock off. Depending on whether you use MS-DOS or DR DOS, type one of the listings shown here into a text editor and save it as a plain ASCII file called NUMOFF.LST.

MS-DOS (Debug) version:

a100
XOR AX,AX
MOV DS,AX
MOV AL,BYTE PTR (417)
AND AL,DF
MOV BYTE PTR (417),AL
XOR AH,AH
INT 21

rcx
10
nNUMOFF.COM
w
q

Then type:

DEBUG < NUMOFF.LST

All being well, you will now have a program called NUMOFF.COM. Test it by pressing Num Lock to bring the keyboard light on, and type NUMOFF. The light should go off.

30 years later, this still isn’t trivial in GNOME… But the book authors get kudos for creativity in finding out how to send someone a working and useful binary via the medium of dead trees.

Q: I post files containing DTP pages and graphics on floppy disks to a bureau for printing. Recently I produced a file that was too big to fit on the disk and I know that I will be producing more in the future. What’s the best way round the problem?

A. There are a number of solutions, most of them expensive. For example, both you and the bureau could buy modems. A modem is a device that allows computers to be connected via a phone line. You would need software, known as a comms program, to go with the modems. This will allow direct PC-to-PC transfer of files without the need for floppy disks. Since your files are so large, you would need a fast 9600 baud modem [Ed: approx 1 kilobyte per second] with MNP5 compression/error correction to make this a viable option.

In this case, however, I would get hold of a utility program called LHA which is widely available from the shareware/PD libraries that advertise in PC Answers. In earlier incarnations it was known as LHarc. LHA enables you to squash files into less space than they occupied before.

The degree of compression depends on the nature of the file. Graphics and text work best, so for you this is a likely solution. The bureau will need a copy of LHA to un-squash the files before it can use them, or you can use LHA in a special way that makes the compressed files self-unpacking.

LHA has a great advantage over rival utilities in that the author allows you to use it for free. There is no registration fee, as with the similar shareware program PKZip, for example.

Every time they brought out a new, larger hard disk, they used to predict the end of the need for compression…