New Acquisition: Acorn BBC Master 128 - 01-AMB15-0056907

Make	Model	Serial Number
Acorn Computers	BBC Master 128	01-AMB15-0056907

Overview

• Manufacturer: Acorn Computers.
• Production Years: The BBC Master 128 was introduced in early 1986 and remained in production until 1994.
• Historical Significance: The BBC Master 128 was the successor to the BBC Micro Model B, offering improved memory, processing power, and expandability. It was widely used in educational institutions and professional environments, continuing Acorn's legacy of robust and versatile computing solutions.
• Architecture: The Master 128 featured the MOS Technology 65SC12 processor, which was faster and more power-efficient than its predecessor. It also introduced advanced memory paging mechanisms to support larger applications and higher-quality graphics.

Specification

• Processor: MOS Technology 65SC12 running at 2 MHz.
• Memory: 128KB RAM, with options to expand up to 512KB using sideways RAM modules.
• Storage: Supported cassette tapes, floppy disks, and hard drives via expansion modules.
• Graphics: Motorola 6845 video controller, capable of high-resolution display modes and Teletext output.
• Audio: Texas Instruments SN76489 sound chip, providing three tone channels and one noise channel.
• Connectivity:
  • RS-423 serial port.
  • Parallel printer port.
  • Econet networking interface (optional).
  • Expansion ports for additional peripherals.
• Expansion: Supported second processors, including Intel 80186 and 65C102, for enhanced performance and compatibility with CP/M and DOS Plus operating systems.
• Operating Systems: Acorn MOS, with optional support for CP/M and DOS Plus via second processors.
• Common Faults:
  • Failure of the CMOS battery, leading to loss of configuration settings.
  • Age-related wear on floppy drives, causing read/write errors.
  • Leaking capacitors in the PSU, which can result in system instability or failure.
  • Overheating issues in systems with multiple expansions installed.

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How Did I Acquire It?

Where Did I Get It From?

I purchased it from Ebay where it was sold as For parts / Not Working

How Was It Described to Me?

The seller described it as.

Vintage BBC Master Computer

Battery changed

Fully Working order

There a something engraved on the side( Please see photo)

Good clean condition

Supplier Photos

Supplier Pictures
What did it come with:
Notes:

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Now I have it in my hands

With the exception of a slightly engraved security mark on the side that looks as if it may polish out, the computer itself looks in good condition.
This does of course mean that the PSU has never been recapped and is most likely going to fail at some point in time.
The advert mentions that the battery has been changed but it is better to be safe than sorry so before we do anything we will take the old battery out and replace it as part of the refurb.

Next steps:

• Remove & replace the batter
• Recap the PSU
• Give it a clean - See what we can do about the markings on the side.
• replacea missing foot.
• Investigate options for modern TV, VGA, Possibly even HDMI output
• Options around floppy disk drives and modern alternatives.
• Rom Upgrades

As I get to each stage I'll create a sperate blog post to document my journey.