Production Years: The BBC Micro Model B was produced from December 1981 to 1994.
Units Produced: Over 1.5 million units were sold.
Historical Significance: The BBC Micro Model B was central to the BBC's Computer Literacy Project, aimed at increasing computer literacy across the UK. It became iconic in education settings, establishing Acorn Computers as a household name.
Specification
Specifications Overview: The Model B featured a 2 MHz MOS Technology 6502A processor, 32KB RAM, and 32KB ROM.
Operating System: It initially ran Acorn's MOS (Machine Operating System) and supported BBC BASIC language ROM as standard.
Upgradeability: RAM could be expanded to 64KB, and additional ROM sockets allowed for language or utility ROMs.
Storage: The machine supported cassette tape storage, and later disk drives were available via expansion.
Connectivity: It included ports such as a cassette interface, RGB output, user port, printer port, and analog input.
Expansion Possibilities: A Tube connector allowed for co-processors, and an Econet network interface provided connectivity.
Common Faults: Known issues include leaking RIFA capacitors in the PSU, and chip failiour after such a long period of time is not uncommon.
How Did I Acquire It?
Description of the Listing: I found this machine on Facebook Marketplace. It was described as being in good condition, including leads, a welcome pack, and boxed. The seller noted that it hadn't been used in 30 years.
Pre-Acquisition Photos: The listing included images showcasing the system, though the exterior box appeared worn and damaged.
Supplier Pictures
Now I Have It in My Hands
Initial Observations: The machine itself looks clean and tidy, and the polystyrene packaging is intact. However, the outer box is significantly worn and falling apart. It came with the welcome tape but lacked the user guide and welcome booklet.
Inspection Details: Upon initial testing, the RIFA capacitors had leaked, leading to PSU failure.
I decided to replace the PSU and will have a go at repairing the damaged PSU later.
Using an RGB2Scart lead on a suitably old TV set, the picture was found to be firm and solid as shown.below, testing the using TV out gave a similarly good picture.
The BBC was found to have DFS1.2 installed using the 8271 chipset.
However upon attaching to both an appropriate FDD and a gotek disk emulator, any form of disk access gave a 00 18 Interface error.
As I have a spare 1770 ADFS kit, I might just upgrade this machine to that and see how it looks.
My Pictures
Next Steps
Repair and Restoration Plan:
Replace the failed RIFA capacitors in the PSU.
Thoroughly clean and inspect all components for further signs of damage or wear.
Attempt to source the missing user guide and welcome booklet to complete the set.
Lets see what upgrade options we have.....
Goals: Restore full functionality and preserve the machine's original aesthetics for display or occasional use.
Challenges: The PSU failure requires careful attention to ensure other components haven't been affected.
Wishlist: Replacement capacitors, original manuals, and potentially a sturdier outer box for archival storage.
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