Nick Brok
This version is expandable and has the following specs:
- 48 Kbytes RAM $0000-$BFFF
- 16 Kbytes ROM $C000-$FFFF *
- 256 Bytes I/O
- One serial port 115200 Baud 8N1
- On board 8 bits Parallel I/O port
On the bus two extra addresses for I/O are predecoded.
On board I/O
- Serial ACIA 68B50 $CF00
- Paralllel I/O $CF20
*IOSEL is active from $CF00-$CFFF
Predecoded:
- CSAUX $CF60
- CSPIA $CF40
For other info look at Scrumpel8a/8b project.
Here an example screen output of my dos09 operating system for the 6809
The OS is running in 16K RAM from $8000 to $BE00 and knows only one disk of 1.3 MB.
Christopher Ramage
Keith
Trevor Johansen Aase
Unfortunately no one could help me with some FAT Filesystem Code in 6809 assembly. (I found some, but those where written in C.) I've written a simple OS on my own. Because of the less memory I have for the OS (16KBytes of RAM 32K for program-space) it's using only one slice of the CF-card. In that slice I can place 1,3MB of data. I use big buffers for file allocation (2560 sectors) and the root directory (8 sectors). The OS can be used, but it's not earning any prizes. :-(