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Upgrading My BBC Micro With a 6502 Second Processor – Is It Really Faster?

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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...
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Upgrading My Beginner 5-Axis Arduino Robot Arm – MG996R Servo + Record & Playback

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After building my original beginner-friendly 5-axis Arduino robot arm , I wanted to go back to the project and make a few improvements. I didn't want to completely redesign the robot. The original arm was intended to be relatively simple to build, understand and modify, so I wanted to keep that idea. Instead, this version concentrates on two major upgrades: A stronger MG996R servo for the shoulder joint A new Arduino program that can record a sequence of movements and replay them automatically I also had to modify several of the 3D-printed parts to accommodate the larger shoulder servo. Updated Shoulder Joint The result is essentially Version 2 of my original robot arm. New to the project? You can find my original beginner 5-axis robot arm build here: LINK TO ORIGINAL ROBOT ARM POST LINK TO ORIGINAL YOUTUBE POST Why these changes? 1. MG996R Shoulder Servo The original arm used an MG90S servo at the shoulder , this servo was struggling with the weight of lifting objects. The torque...
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How to Build a 5-Axis Robot Arm with an Arduino (Beginner Friendly)

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Fully Assembled Robot Arm Building a robot arm might sound like an ambitious first robotics project, but it doesn't have to be. With a 3D printer, an Arduino Uno and a handful of affordable hobby servos, you can build a fully functional five-axis robot arm while learning the fundamentals of mechanics, electronics and programming. This project was designed with beginners in mind. There are no custom PCBs, expensive components or specialist tools required. Instead, the focus is on building something that is easy to assemble, easy to understand and, most importantly, easy to improve. Like any engineering project, this robot didn't work perfectly the first time. In fact, solving the problems taught me just as much as building it. Rather than hiding those mistakes, I've included them here so you can avoid the same issues when building your own.           By the end of this guide, you'll have everything you need to build your own robot arm and a solid foundation ...
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Installing Superior Software Speech! on the BBC Model B

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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...
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Installing a Sideways RAM Board in the BBC Model B

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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...
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