Make It With Matty

I've added an original Acorn 6502 Second Processor to my BBC Model B. Connecting it is easy. The interesting question is what it actually does. The external unit contains another 6502 processor running at 3 MHz and 64 KB of its own RAM. It communicates with the BBC through Acorn's Tube interface, allowing programs to run on the second processor while the BBC handles things such as the display, keyboard and storage. Rather than just showing the installation, I wanted to answer one question: How much faster does it make the BBC Micro? Test 1 – Raw BASIC Performance First I wanted a simple CPU-heavy test. 10 MODE 7 20 CLS 30 PRINT "BBC 6502 CPU BENCHMARK" 40 T%=TIME 50 FOR R%=1 TO 5 60 FOR I%=1 TO 100 70 X=SQR(I%)+SIN(I%/50)+COS(I%/25) 80 NEXT 90 NEXT 100 E=(TIME-T%)/100 110 PRINT "TIME = ";E;" SECONDS" I ran exactly the same program first on the BBC Model B alone, then again with the 6502 Second Processor enabled: - the BBC Model B alone the BBC wit...

Speech! is one of the most impressive software achievements ever released for the BBC Micro. It generates understandable speech using nothing more than the BBC Model B's standard sound hardware, no dedicated speech synthesiser required.  In this project, I'll install the Speech! ROM into my BBC Model B, explore how it works, and hear the machine speak for the first time. Programming the ROM I found two archived versions of the Speech! ROM: An 8 KB image A 16 KB image ROM LIBRARY After comparing both versions, it turned out that they contained the same speech engine. The larger ROM was simply padded to fill a 16 KB ROM image. Since my Sideways ROM board uses AT28C256 EEPROMs , I programmed the 8 KB ROM into the EEPROM, repeating it across all four 8 KB banks so that it could be selected correctly by the ROM board. Burning the ROM Programming was carried out using my TL866II Plus Universal Programmer . Installing the ROM Installing the ROM was straightforward. I place...

The BBC Model B is one of the most expandable home computers ever made, with a wide range of hardware upgrades still available today. In this project, I'll be installing a Sideways RAM board into my second BBC Model B and using its built-in diagnostic commands to verify that the installation has been successful. Installing the Board Before fitting any upgrade, I always take the opportunity to inspect the inside of the machine. My usual checklist includes: Dust buildup Loose ICs Corrosion Leaking capacitors Damaged PCB tracks Previous repair work Fortunately, this BBC Model B was still in excellent condition. Installing the Sideways RAM board is fairly straightforward. Unlike a traditional Sideways ROM board, this upgrade plugs directly into the 6502 CPU socket , with the processor then fitting into the socket on top of the board. Several flying leads are connected to the motherboard to provide the additional control signals required by the board. Although the installation isn't...

In my previous post, I installed a Sideways ROM/RAM board into my BBC Model B. That upgrade gave me several additional ROM sockets, allowing me to expand the machine with extra software without constantly swapping ROM chips. It also gave and extra 32k RAM. Now it's time to put that upgrade to good use. In this guide, I'll be programming two ROMs that I think every BBC Model B owner should consider installing: Advanced ROM Manager (ARM) – a powerful utility for managing your Sideways ROM board and Sideways RAM. BASIC Editor (EDIT) – a much friendlier editor for writing BBC BASIC programs. I'll be programming both ROMs using my TL866II Plus Universal Programmer and XGpro  software before installing them into the BBC Micro. Finally, I'll demonstrate one of ARM's most useful features by switching between the original Acorn DFS and Turbo MMFS filing systems. What You'll Need For this project I used: BBC Model B Sideways ROM Board Two AT28C256 EEPROMs ...

The BBC Model B is one of my favourite retro computers. Even over 40 years after its release, there are still plenty of upgrades available that make using it even more enjoyable. One of the most useful upgrades is a Sideways ROM board , which allows you to install several ROMs at once instead of being limited to the standard motherboard sockets. In this post, I'll walk through installing one into my BBC Model B and show the finished result. What is a Sideways ROM? The BBC Model B stores much of its operating software in ROM (Read Only Memory) chips rather than loading everything from disk. These ROMs can contain things like: BBC BASIC Disk filing systems Utility software Programming languages Diagnostic software As you begin expanding your BBC Micro, you soon run out of ROM sockets. A Sideways ROM board solves this by providing additional ROM sockets, allowing multiple ROMs to remain installed at the same time. Why Install One? Although the BBC Model B is an inc...