Search Posts:

Cassette Signal Issue

View Entire Thread

Return to Threads

  by Bill Degnan - 07/21/2018 11:07
Juergen writes:
> Inquiry Contact Information Name: CMGB
> Email: cmuseumgb- at -gmaildot com Comments:
> In regards to blog post titled Rockwell R6500 (AIM 65):
> I am one of the founders of the Computer Museum in Basel (CMBB/CMGB). We have 2 AIM 65 units that seem functional. However, we're experiencing problems with the cassette drive when trying to read back. We tried to record using cassette recorders and also a modern PC through line in and the audio signals are clearly recognizable (from pin M). A connection to pin L and using the corrected program to test readback from "micro_11_apr_1979_text_syn_read_program_AIM65.pdf" only displays the "N" on either AIM 65 system. The cassette interface potentiometers are sealed in one of the units by the manufacturer and have never been changed as far as we can tell. Is there anything we could try to get reading from tape to work? We are running our of ideas. Is there any way to visualize the incoming signal through a small program other than the one from the magazine?
> Kind regards from Basel
> Juergen

My reply:

My first thought is that the power isn't right, the cassette needs an extra line I believe 12V, but I have to check. I have these notes: Corrections to Guide which talks about the cassette test routine being in error. I assume the PDF you're referencing corrects this.

I don't know where micro_11_apr_1979_text_syn_read_program_AIM65.pdf is located (on this site?) so I will have to consult an original copy of the magazine and get back to you.



Buy a Commodore Computer Poster

Popular Topics and FAQs

  • Commodore B Series Tips and Tricks
  • Aerocomp TRS 80 M 1 Expansion Unit DDC
  • Items Wanted
  • Lobo Max 80
  • Zenith Z-19-CN
  • Prototype PET 2001 photo
  • Using Toggle Switches to Analyze Memory
  • Commodore Disk Archive Project
  • PET 2001 Prototype at Gametronics 1977
  • Jim Butterfield Photo
  • IMSAI 8080 With Processor Tech. Cutter
  • Secrecy is the keystone of all tyranny
  • Cromemco System Three
  • Northstar Horizon - Boot Problem
  • Computer History and Restoration Links
  • Commodore BX-256-80 - 8088 Co-processor
  • S-100 board testing with Z-80 ICE
  • Donner 3500 - an early portable computer
  • Digital (DEC) PDP 11/05 NC Assembly
  • Univac 1219 rescue
  • Fido BBS listing node list 6-13-1986
  • PDP 8e
  • MITS 88-2 SIO (2SIO) for BASIC
  • Visual Technology Inc Model 1050
  • Amiga 2500 Restoration
  • The Evolution Of IBM Computers
  • Replacement teletype print hammer head
  • Archiving and Copying Software 101
  • Computers Built 1940 - 1950
  • CBM B-520 (a.k.a B256-80 or B500 256)
  • RCA COSMAC Microkit
  • Commodore 64K C-116 Mods
  • MITS 8800b Turnmon 9600 baud
  • Catweasel, 8in and 5 1/4
  • Raspberry Pi as Gateway to Internet
  • Digital PDP11 late 1969 early 1970
  • PDP 11/40 72 inch cabinet model
  • PDP 11/40 Industrial 11 model
  • Digitial MicroVAX 3100 30 System
  • Digital VAX 4000-200
  • Commodore 64 / 1541 DRIVEKNOCK
  • Booting the System Using RL02 drive
  • PACS: Reflections by Kathleen Mauchly
  • Tele-Graphic Computer Systems Inc.
  • Commodore B Series SID Jukebox?
  • Installing Core into PDP 11/40
  • Setting Up OpenVMS 7.1 DNS CLERK
  • Felt-Tarrant Comptometer Model J
  • NextStation Color
  • Digital Rainbow (PC100-B2)
  • 1970 Compusad Compulogical Tutor
  • Archiving Papertapes Using DSI NC 2400
  • 1976 P.C.C. Features the MAI JOLT 6502
  • 1961 Beckman DEXTIR Computer
  • UNIVAC 1 and UNIVAC File Computer 1
  • Past Issues:

    tricord m4050c logoplate

    This image was selected at random from the archive. Click image for more photos and files from this set.