gvw1@ihuxp.UUCP (George V. Wilder) (06/21/84)
I am trying to learn how to write drivers for this CP/M(tm) card, which runs in an Apple(tm) //e. I have some information--the OEM information that one can get from PCPI--but I am looking for sample drivers that other people have written; and in general I would be interested in sharing notes with other users. I will be developing a graphics driver that will work with the Double Hi-Res mode that the Apple //e has. George V. Wilder ihnp4!ihuxp!gvw1 (312) 979-1937 -- George V. Wilder ihnp4!ihuxp!gvw1
gvw1@ihuxp.UUCP (George V. Wilder) (08/07/84)
The PCPI Appli-Card(tm) is a versatile CP/M(tm) card for the Apple II (or IIe). Using the OEM software that can be obtained from PCPI, one can write special purpose "drivers" that down load into the Apple at boot time. The card comes with a standard set of drivers for controlling the console, printer, etc. Supposely these drivers can be relocatable or can be loaded into an absolute location at boot time. Now to my question for those of you who have a PCPI Appli-Card... I have been able to write a relocatable driver that allows one to call a subroutine in the apple. Yes I know that there is a general command for doing this, but sometimes values have to be placed in the X, Y, and/or A registers before calling the subroutine (eg., calling some of the graphics subroutines in the Applesoft ROMs)--and that's what my driver does. My question is: I am trying to make the driver so that it loads in an absolute address (eg., at $4000 just above Hi-Res page 1). I cann't get it to work--my system hangs when I boot it with this driver installed as an absolute loading driver (It works great as a relocatable driver.). Can anyone give me a hint??? Thanks! George V. Wilder ihnp4!ihuxp!gvw1 1 (312) 979-1937 -- George V. Wilder ihnp4!ihuxp!gvw1