Search Posts:

CBM B128-80 Serial Bus


Return to Threads

  CBM B128-80 Serial Bus by Bill Degnan - 04/15/2013 10:19
CBM B128-80 with Fast Bus cartridge
CBM B128-80 with Fast Bus installed to allow a person to switch from a serial-type disk driveand an IEEE drive. In this case I am switching between a CBM 8050 IEEE-type drive, and a VIC 1541 serial drive (on top of the monitor). Click for larger view.

A closeup of the two required components of a Commodore B Series "Fast Bus" system. On top of the B-128 is the Serial Bus Interface converter box. This is the device that switches betweem serial and IEEE drives. A RAM expansion cartridge is installed into the B128, in this case a new 24K RAM cart in bank 15 ($2000-7FFF) and handles the serial bus RAM space. The original carts covered $2000-2FFF (not pictured). The Fast Bus program is loaded from diskette on the 8050. (CBUG 84). Click for larger view.

B-128 Serial Bus Interface
Closeup of the B-128 Serial Bus Interface, which allows a person to toggle between a serial drive and an IEEE drive, or reset the serial port. Click for larger view.

More on this soon.

  B128 Serial Bus Photo by Bill Degnan - 04/17/2013 16:29
CBM B128-80 Fast Bus cartridge pcb
Photo of the PCB of the B128 Serial Bus. Click for larger view.

More photos

  Fast Bus Update by Bill Degnan - 08/12/2013 14:32
Put up set up instructions that came in the box here

Power up test: Perform the following instruction: PRINTPEEK(56321) The number returned should be 59.

CBUG disk #84 appears to have all Fast Bus-centric programs on it.

CBUG articles

Tells you more how the 24K cart plus Fast Bus, and software works.

One thing I learned is that you can actually copy from serial drives to IEEE drives. The system assigns the IEEE devices as 4-23, Serial devices 24-30.

IEEE printer 4-7
IEEE drives 8-23
Serial printer 24-27
Serial drive 28-30



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:

    Challenger 1P

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