Graham Dearsley

One other thing about Atari BASIC, you don't need the LET. If your program line doesn't start with a keyword then LET is assumed so "10 A=5" will do. If you do use a LET then Atari BASIC will allow you to use a reserved keyword as a variable name but DON'T ?

You can OPEN any device that has an entry in the device handler table, its held in RAM so it can be added to and the device letters and entry address for the built in devices are copied there at system boot or reset. There is no D device until you boot from a DOS disk, thats why you get non existent device errors if you forgot to boot DOS. DOS loads its file management system as device handler "D:" and adds it to the table. Just thought i'd mention it ?

Glad that's what you wanted ?

I think the book your looking for is The Atari BASIC Reference Manual.

An example to open a file for output would be. OPEN #2,8,0,"D:MYFILE.TXT" You can replace the 8 for different open modes. 4=Input 12=Input/Output 9=Append Do not open the same file for Output again unless you want to erase it ! You can send a record to your open file with. PRINT #2;"NAME" If you want tab spaces between your records replace the semicolon with a comma. You use INPUT #2,A$ to read records.

Another reason not to use mode 8 artifacting for colors is that it just dosn't work on PAL tv's. People in the UK with an Apple II had to buy an NTSC monitor if they wanted color because the Apple II can only do color high res using artifacting. Look up the Apple ll graphics system, I think you will think its a bit rubbish like I do ?

Yep, In 1981 I used to do the same for my DLI and VBI routines, write the assembly out on paper and then look up the codes in the back of the Programming the 6502 book. Then I got the assembler/editor cartridge. Oh the bliss of being able to jump to a label ?

I think that just 1 colour is enough for the rainbow routine but it has to be independent of the background colour if you don't want that to be a rainbow as well ?.

Yep again, so you can ?

Yep GR.0 only gives you shades of the background colour for your text. You could use DLI's to change the background colour on every line but obviously that changes the background colour ?. If you can put up with double width characters then GR.1 gets you 4 colour text and then you CAN use DLI's to change just the text colour on every line.

It is a pity that the OS user manual was never comprehensively updated for the XL/XE OS. There is a supplement but it doesn't cover everything. There is also an internal document that describes the PBI and how it handles loading drivers into the space normally occupied by the floating point package, if you can find it, but it was never published officially.

And the OS user guide will give you the AUX codes to use for things like OPEN for input, output, append etc.

And just for anyone who is still in any doubt. With the POINT command in Atari BASIC, the X and Y variables MUST BE VARIABLES, a number will not do ???

I found the Type A Tune program at the end of the BASIC Reference Manual interesting when I finally looked at it after several years ?

The Atari 8 bit articles on Wikipedia are very odd indeed, one day you can read them and they will be quite good, but if you come back a week later you can find that someone has edited them with complete rubbish. Go figure but I am beginning to suspect C64 fans ?