Is there a vector to clear the screen (from Dos)?

[+Larry]

Easy enough if you are in Basic, but if you are at the MyDos menu, you simply get a "no such item" error.

 

There must be a vector -- anybody know what it is? I need to be able to do a "Run at Address" (MyDos M).

 

Thanks,

Larry

[Rybags]

Not really, although there of course is a block of code in the OS dedicated to clearing the screen but not really covered by a vector.

Although the handler table for E: and S: does contain the address for the OPEN operation - but CIO expects certain value in registers and some of the IOCB Ram-based variables.

 

Like much of the S: handler though, it's a generic routine which is mode independant, ie works on a bitmap equally as it'd work on a text window or full screen.

 

Alternates:

. run at $E474 - performs a warmstart same as if you'd pressed Reset, although that's probably not what you want.

. force a re-open of E: If you have means to modify memory from a Dos option then it might be easy. IIRC MyDos doesn't allow such a thing though. Some variants of Copy command at least in Atari DOS will re-open E:

 

Is this in an operator entered situation, or some sort of Batch mode?

Edited November 3, 2013 by Rybags

[Rybags]

OK, I tried with the floppy version I've got here, no guarantees of stability though.

 

The OPEN vector you need is for the E: device, the table is at $E400 in ROM.

 

Use a utility to get the hex value from $E400, $E401. The Run address you want will be that value +1.

 

e.g. the OS I have with Atari800Win+ gives $FB $F3 so the address I run from is $F3FC.

[+Larry]

Hi Rybags-

 

Thanks, I'll give that a try. I'm "sort of" using a batch -- "Fast Fingers" from Antic to set up the system as I want it.

 

http://www.atarimagazines.com/v2n11/fastfingers.html

 

A neat little utility that runs as an autorun.sys and can automatically do things from Dos or Basic (although for other reasons, I can't clear the screen as I'd wish from Basic).

 

The main purpose of my batch is to activate MEM.SAV since I have no expanded ram in this particular machine, then return to Basic XL/XE. But I'd like the screen to look as if it has been just booted -- no extra "trailings" on the screen from the batch operations.

 

I'll let you know how this goes.

 

-Larry

[Rybags]

OK - I get it, I did something similar that worked to load the AsmEd cart to Ram if you pressed Space during Dos boot.

 

You could modify it, e.g. set the text colour same as background until the automated typing is finished.

and/or just add extra typing such that the Dos menu is shown as normal (doesn't pressing RETURN accomplish that? )

 

I see now... you enter B to run cart but it still has the Dos menu present unlike Dos 2.x which gives a clear screen with READY prompt.

 

You could just add something like "GR. 0" to the typing which should give READY prompt same as if booting normally. Of course that won't work if you have some other language cart inserted.

 

Possibly modify the autotype program such that there's optional extra stuff that only gets entered if the Basic Rom is inserted (just test the 1st 16 bytes @ $A000 or something)

[+Larry]

Hi Rybags-

 

No, doesn't quite work. It clears the screen, but in returning, MyDos puts the menu right back up.

 

I probably am going to have to figure some (non-conventional) way to do this from Basic.

 

-Larry

 

Edit: After trying several more things, I've come to the conclusion that the "cleanest" thing I can do is to leave the system at the Dos menu. That way it will work regardless of the cartridge (or none) that is in the system at the time.

[Marius]

What if you would add a clear screen routine as a binary file to your batch?

[Kyle22]

With any DOS that has the ability to do batch operations, it should be easy. For SDX, just say CLS. You could copy or type a short file to the screen that had esc[clear] in it.

[+Larry]

No, this is MyDos, and it insists on putting back the DUP.SYS menu.

 

For everything I tried (including clear screen routines), I end up with the menu before I go back to Basic.

 

I finally "fixed" this by using a patch to set MEM.SAV. Works perfectly, with no "unintended consequences."

 

Thanks for all the suggestions!

 

-Larry