Re: device driver source code

["GarberStreet" <willy46pa@comcast.net>]

"Paul Schlyter" <pausch.NO@SPAM.saaf.se> wrote in message
MPG.1c6bfd5e4a238837989681@news.individual.net">news:MPG.1c6bfd5e4a238837989681@news.individual.net...
: In article <GOadnQ-QfaifpJzfRVn-ig@comcast.com>, willy46pa@comcast.net
: says...
: >
: ><aiiadict@gmail.com> wrote in message
: >1107375994.852034.59440@l41g2000cwc.googlegroups.com">news:1107375994.852034.59440@l41g2000cwc.googlegroups.com...
: >:
: >: GarberStreet wrote:
: >:
: >:> I need some source to learn about device drivers from.
: >:> Got any of those???
: >:
: >: device drivers for what?
: >:
: >: IIgs?   I have code somewhere.
: >
: >Yes, IIgs drivers.
: >
: >: IIe?  Prodos?  Dos3.3?  the only
: >: I'd be able to help with is
: >: 6502 without any interface
: >: to prodos.  I've coded many
: >: hardware drivers, but these
: >: are for my own playing with
: >: and don't follow any standards
: >: besides interfacing software
: >: with hardware.
: >
: > If you don't mind someone else seeing them, ok.
: > I just need to see something with labels so I know
: > what is happening. IIe code would be ok, even in
: > DOS. Figured you'd be the most likely to have
: > some that would help me with my own code, being
: > you've built the robot and all.  Anything you don't
: > mind letting out. I will keep it confidential.
: >
: > Apple II Forever, and Apple II Together,
: > Bill @ GarberStreet Enterprizez };-)
: > Web Site - http://garberstreet.netfirms.com
: > Email - willy46pa@comcast.net
:
: Apple DOS didn't have much support for device drivers (i.e.
: logically separate pieces of code which matched a hardware
: interface to a software interface).  The best examples of
: "device drivers" in Apple DOS are probably the code in those
: 256 byte ROM's on the peripheral cards for the Apple II,
: mostly I/O cards of various kinds.  The DOS RWTS can also
: be considered a device driver (there is equivalent code
: in all other Apple II OS'es (Apple Pascal, Apple CP/M,
: Prodos, Apple OS/9, ....), and so can the monitor ROM
: routines for writing to the Apple II screen memory.
:
: Another OS, which was contemporary to Apple DOS but which
: provided much better support for device drivers as well
: as mapping logical devices to physical devices, was
: CP/M.  All flavors of CP/M had a BIOS (Basic Input-Output
: System) where all the drivers for the I/O devices was supposed
: to reside.  The software interface of the BIOS was public.
: CP/M had two kinds of devices: character devices (keyboard,
: screen, printer, and an auxiliary device which often was a
: paper reader/punch in the early days of CP/M but which later
: became a serial port), and block devices (i.e. disk drives
: -- floppy disks, hard disks, RAM disks).  The character devices
: could be mapped onto one another by putting appropriate values
: in the IOBYTE.  Each block device had a "disk parameter table",
: which allowed using disks of widely varying formats and sizes.
:
: So if you want a good example on how to implement device
: drivers, Apple CP/M is a better example than Apple DOS.
: By today's standards, both Apple DOS and CP/M are of course
: quite primitive -- but that's also an advantage because they're
: also simple and much easier to understand.

All good advice, but, that won't help me write a device driver
in GSOS, which is where I want one. I could patch the card's
firmware for a driver in 8-bit, but not having the source for the
card, where would that go. Frankly, I haven't tried to access
the device in question from the bare card as yet. I must get to
that soon. If that works then a driver for GSOS would be trivial.

Apple II Forever, and Apple II Together,
Bill @ GarberStreet Enterprizez };-)
Web Site - http://garberstreet.netfirms.com
Email - willy46pa@comcast.net