The CPC Microsystems SBC-65 is a 6502-based single board
computer which is AXY
platform
compliant. The AXY
platform is a standard 6502 microcomputer system specification
that is being developed by a group of homebrew computer enthusiasts. It
includes hardware and system and application software.
Address Range | Comment | SBC-65 Usage |
0000 - 1FFF | RAM1a 0000 - 07FF | 6116 |
RAM1b 0800 - 9FFF | 6116 | |
RAM1c 1000 - 17FF | to backplane | |
RAM1d 1800 - 1FFF | to backplane | |
2000 - 3FFF | RAM2 | to backplane |
4000 - 5FFF | RAM3 | to backplane |
6000 - 7FFF | RAM4 | to backplane |
8000 - 9FFF | RAM5 | to backplane |
A000 - BFFF | I/O1 A000 - A7FF | ACIA @ A000 |
I/O2 A800 - AFFF | VIA @ A800 | |
I/O3 B000 - B7FF | Service Port @ B000 | |
I/O4 B800 - BFFF | to backplane | |
C000 - DFFF | ROM 2 | to backplane |
E000 - FFFF | ROM 1 | 2764/2864 |
LDA #$A5
LOOP: STA $B000
JMP LOOP
I used this to verify board operation. Obviously I had to link this at E000 and set the reset vector to E000 as well. The service port also played a major role in debugging and getting the ACIA working. Since the serial port is now working the service port's role is mainly to strobe a "Knight Rider" style pattern so I can see things are running okay.
Here's a nice screen shot snapped from my old Sparcstation IPX in which you can see the boot screen of the SBC-65, with the R-SYS prompt. This is running through the serial port, /dev/ttyb, using tip. In the background is a simple C source file that boots up and prints the prompt. This is not actually the source that's running you may notice. Also note how the terminal heading has the title "Rabbi 2000 R-SYS Development" - this is because I just run the same terminal window for both the 6502 stuff and the Rabbit 2000 projects - they both plug into /dev/ttyb. This is mainly due to the fact that I have so far only made up one serial cable for the Sun box.
That's all for now folks. Pretty soon, this page will become may more
pages and be better organised, but I didn't want to put in loads of "under
construction" messages, and at the same time I wanted to get something
on-line.