serafine

Hi folks! I have an old Atari 800 computer with a 1050 Disk Drive and haven't messed with them in years. I recently set things up and the computer comes on just fine...cartridges boot just fine and games can be played as usual...without cartridges, Memo Pad comes up as expected. When I hook up the 1050, put in a disk of any kind, DOS, blank, bootable files, I get the same result...computer drops into Memo Pad and no disk access occurs (without cartridges), or pops into BASIC with that cartridge installed, but, again, no disk access of any kind occurs. If I have the "READY" prompt in BASIC, and type "DOS" it drops into Memo Pad. If I type a LOAD command with the correct syntax, I get an ERROR 130. What do you suppose is the problem? I have 3 different i/o cables and the results are the same with all three. Do I have a bad circuit board? Keyboard works, sounds and graphics all work. I am puzzled. Thanks in advance for the help!