` START VOL. 3 NO. 7 / FEBRUARY 1989`

# Clipboard

Compiled by Heidi Brumbaugh

### Virus Update

In Special Issue Number Four of START, the Clipboard ran an item on how to protect your computer and disks against viruses. At that time, we knew of no confirmed viruses on the ST; since then we have seen an ST virus. Because viruses are a serious threat to Atari owners, we recommend you obtain a copy of the public domain program Virus Killer (VKiller) by George Woodside and use it to check all of your disks for viruses. VKiller will give you the option to stamp out any virus it finds.

If you don't have access to the online services, try your local users group or a public domain disk distributor. Read the instructions and warnings carefully; misuse of this program can be dangerous.

### Coincidence or Clevor Planning?

If you look on any ASCII chart, you can see that the upper case characters and the lower case characters are 32 characters apart (ASC("a")-ASC("A")=32). On further consulting the chart, you'll see that the space character has an ASCII value of 32. Coincidence? Not at all.

The binary value of 32 is 00100000. The binary value of A is 01000001; a is 01100001. To swap these two values, all you need to do is flip one bit. A GFA BASIC function to do this is:

Deffn Swap\$(A\$)=Chr\$(32 Xor Asc(A\$))

Call this function using Fn:

A\$=Fn Swap\$(A\$)

Similarly, assign the expression Chr\$(32 Or Asc(A\$)) to a function to convert a letter to lower case regardless of whether it was upper or lower case to begin with. XOR the result with 32 to convert the character to upper case.

Where does the special value of the space come in? This is so you can perform a logical OR on a space without changing its value, useful when you are manipulating a string of words separated by spaces.

### Backups in a Flash

If you have two hard drives and have access to a second ST, here's a quick way to transfer files between the two: Connect the two computers using a null modem cable and boot up Flash on both machines. Set each computer to the highest possible baud rate (19200). Set the same drive and directory path on both ST's, and then use Flash's Ymodem batch transfer set to "*.*". This will automatically transfer all contents of the folder on the computer set to "send" to the same folder on the computer set to "receive." Note: This will only work on version 1.6 of Flash; if you aren't sure how to access the Ymodem batch transfer option, read the disk-based documentation.

This makes it easy to use a second drive as a backup without having to go through any tedious (and time-consuming) floppy disk swaps.

### Gamester Hints:"Virus" by Rainbird

Here's a tip on the new game Virus by Rainbird, thanks to Wolf Griffey in Antics customer service department. When you're seeking the Cedar Ships, try reconfiguring the controls for "natural feel" at the beginning of the game. Also, look for your target using both sound and sight.

### Give it some Slack

If your printer's tractor feed is jamming up after two or three pages, try tightening the left tractor wheel but leaving the right tractor wheel loose.

### DEGAS on Megas

START recently received a phone call from a reader complaining that his new copy of DEGAS Elite wouldn't work on his Mega 4. He said when he called Electronic Arts they told him that they knew about the problem but weren't planning on publishing an update.

This phone call surprised us, primarily because DEGAS works on START's Mega 4 without a hitch. What we discovered, however, was that DEGAS will lock up when you run it if there are too many GDOS fonts installed. Try booting the computer without GDOS (rename it to GDOS.PR_ in the AUTO folder) and then make sure DEGAS works. Try GDOS again, this time editing the ASSIGN.SYS file down until it's small enough for DEGAS to run.

### Desktop Cleanup

You can open a window on the Desktop to a nested directory, or folder, many Ievels down. Clicking on the close box in the upper left corner of the window or clicking on Close under the File menu will bring you the the next level up in the directory. However to close the window completely without clicking through any number of directories, simply click on Close Window under the File menu.

Got an ST trick or tip to share? Send it to Clipboard, START Magazine, 544 Second St., San Francisco, CA 94107.