[Coco] Howto for Altera DE1?
Gary.Becker at amd.com
Mon Jun 28 23:43:03 EDT 2010
The large disk you downloaded from the Yahoo group is for the old version on the Xilinx board. In that version, the serial port was directly used by the 6809 processor. It also used a modified version of Disk BASIC ROM instead of the normal ROM. Depending on what you want to do, there are several options for boot disks. But before you decide which disk to use, I need to make sure you are using the correct FPGA file. The one on the Yahoo group only supports the standard floppy disk controller. If all you want to do is get NitrOS9 running, use the standard CoCo3 6809 boot disk. It is a 40 track double sided disk. This workd well with the standard FDC FPGA and the DW3 server. The CoCo3FPGA runs in "legacy" mode and the disk controller appears to all the software to be a standard floppy disk controller. If you want to go to the next level, then you will need to get a newer version. Aaron mentioned he could send it to you. I am not 100 percent certain that that version will work at 115200 bps. I just fixed an issue with my code where it would only run at the faster speeds. I plan on uploading a newer version, but I have been busy and have not had the time to finish it yet. Hopefully later this week. With the newer version, run the becker disk as Aaron has suggested. He says it will also work with the DW3 server, but I have not tried it. If you switch to the newer DW4 server, it might take a newer version. There have been some changes that made the 2.01 version unusable. Aaron knows more about that than I do. When you use this disk, you need to be very careful that you use the correct disk driver / descriptors. Both the DW driver is loaded with descriptors for /dd. /x1, /x2.... The standard FDC controller is also loaded with descriptors /d0, /d1, and /d2. If by accident you try to use the standard FDC disk, the FPGA board will lock up. It is not designed to be run in both DW mode and standard FDC mode at the same time.
As Mark McDougall mentioned, these types of issues are expected. This project is still in early stages of development and there is zero documentation. Before I release an official version, I will put together a complete user manual. It will be similar to the one for the earlier version on the Xilinx board. I am impressed that you have made it this far this fast with no documentation. Thanks go to Aaron and Mark.
On Mon, 28 Jun 2010, Aaron Wolfe wrote:
>> If I wait, sometimes I'll see one or two sectors more being read. But the
>> display never changes.
> I've not tried it with DW3 but it should work to get booted at least
> (the internet and other DW4 stuff obviously won't work, but the driver
> negotiates with the server to determine whether to load this). If I
> get time I will try it on DW3. You're limited to 115k on DW3 so make
> sure your serial speed is set accordingly.. doubt you'd get that far
> if it was wrong though.
I wouldn't think so, no. Both SW8 and SW9 are off, so that's 115k baud
according to a note from Gary. SW2 and SW3 are on to select MPI slot 4.
All others off.
> Gary's disk controller checks the disk size every couple seconds. If
> you haven't waited long enough since inserting the disk, it might be
> thinking it's a different size than it really is?
I have the disk mounted before the board is programmed. Nothing is
changed after that point.
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