It looks like my Radeon X1300 graphics card has faulty video memory. 8-bit and 16-bit screens have vertical lines in them, eight and four pixels apart, respectively. After performing a memory test, bit five of every of every eighth byte remains set to one, regardless of what is written. This defect is invisible in 32-bit truecolour mode since that bit is part of the invisible alpha channel. The Visiontek Radeon X1300 that I have has a 64-bit memory bus, i.e., eight bytes wide. Thus, this behaviour is consistent with a single data line being faulty; possibly a bad solder joint or something similar. Unfortunately the memory chips are fine-pitch ball grid arrays, so it is not something that I could fix. An x-ray machine would be required to even check if a solder joint was bad.

Today (13 October 2008) I have successfully opened a screen using the Picasso96 RadeonHD driver. There are still a few issues to sort out. For example, the colour look-up tables are not set, resulting in some funny colours. Also, the 16-bit screen-modes do not display correctly. Nevertheless, this is an important milestone. It is now possible to open screens (including workbench) via this driver. Being just a frame-buffer driver, there is no hardware acceleration for graphics, meaning that all rendering must be performed by the CPU. As a result, dragging windows can be sluggish. Interestingly, compositing does work, but switching it off speeds up the system.

The skeleton RadeonHD.chip driver has now progressed enough that the screen mode preferences editor now lists screen modes for the Radeon HD card. This is another small but important step toward a working driver.  At present, these functions simply output debug information in order to let me know that they are being called. Thus, one cannot actually use any of these screen modes since the functions that perform that task have not yet been implemented.Nevertheless, this is good progress.

Since receiving the developer material for Picasso96, I have built a skeleton driver: RadeonHD.chip. At present this skeleton does absolutely nothing; it fails on initialization of the graphics card. However, the system will correctly identify a Radeon HD graphics card and load the RadeonHD.chip driver. This is, thus, a small baby step toward a basic frame-buffer driver (which will be the first milestone). 

I now have access to all the required developer documentation and source-code for developing a Picasso96 driver. There is quite a volume of information to wade through. The goal now is to work toward a simple framebuffer driver; no hardware acceleration, just a framebuffer. 

A generous donor has provided me with a Diamond Radeon HD 2400 pro PCI card. I am pleased to announce that, with a small amount of coding, the Radeon HD driver can now initialize this card, and open a screen. This card uses the RV610 chipset and is one generation newer than the Radeon x1300 that was originally used as test card. Now that two cards from different generations have successfully been initialized using the code, it should be fairly easy to add support for more. In fact, many R5xx and R6xx cards should work without any changes to the code.

Today marks the first milestone in the RadeonHD for Amiga OS 4 project. A Radeon X1300 graphics card has successfully been programmed to open a 1280x1024 true-colour screen and an image has been displayed. The graphics card was a VisionTek Radeon X1300 256MB PCI card that has been plugged into one of the PCI slots in my Amiga-one for over half a year now. With this success, I am now confident that I can, in time, write a proper Amiga OS 4.x driver for this card. Thus, this project is now revealed on this website for the first time.