Just dragged my Atari 800 and 810 out of storage fro 30 years. The 800 powers up and I am getting video and sound out,
I connected the 810. It powers up and goes through its startup procedure. But is I power up the 800 with no cartridge the disk does not load. If I insert the BASIC XL cart and type DOS the Atari goes right to the memo pad.
I disconnected the SIO cable from the drive and tried looking for data and clock out with n\my scope but I see no transitions
Data Output: Low and remains low
Command: High and stays high
Clock Out:: : High and stay high.
I did a continuity test of the cable and it looks good.
The 810 is not connected. Is there something that needs to be jumpered that tells the computer there is a device on the serial port before it sends data?
Edit: I see that data out is open collector. I added a 10k pull up to 5V. Still no data out. . Just remains high. Trying to figure out how to send data out. I did it before,built my own Rs232 interface, but that was 30 years ago.
Edited by spinnaker15136, Sun Apr 21, 2019 12:23 PM.