ReCo6502 Second Processor

The ReCo6502 is a remake of the original Acorn 6502 second processor using modern components. Essentially, this reduces it's size and power consumption whilst increasing the speed at which it can operates from the original 3MHz up to a software selectable 14MHz. The available memory of the Second Processor is also increased from the original 64KB to 512 KB.

A ReCo6502 in it's extenral guise

Here with the case off, you can see the low chip count compared to the original Acorn 6502 Second Processor which is the significant factor in the lower power consumption of the Second Processor.

Opening the ReCo6502 second processor

A closer look at the board reveals that it's running a Western Digital 65C816 processor which is running in 65C02 mode to allow compatibility with the BBC Micro.

The ReCo6502 second processor circuit board

New Commands

The ReCo6502 Second Processor introduces a couple of new commands to the BBC Micro being *SETUP and *GoS.

*SETUP provides a high degree of control over the configuration of the ReCo6502 and allows you to choose the clock speed, memory addressing model and whether to load HIBASIC into RAM or not.

*GoS places the computer into Supervisor mode.

Playing Elite

Now the obligatory instructions for configuring the ReCo6502 to play Elite at a sane but faster speed and of course at full speed if you can.

The original BBC Micro CPU runs at 2MHz, the Acorn 6502 Second Processor runs at 3MHz. The ReCo6502 can run at several different speeds up to 14.7MHz so as you can imagine, running at around 7.5 times the speed of the original game and 5 times the speed of the Second Processor version can make the game quite nippy indeed!

So here's how you setup the ReCo6502.

Type *SETUP and press ENTER
Press L for Linear Memory
Press N to disable
Type *SETUP and press ENTER
Press C for Clock speed
Press D for 8.84MHz

After that, the ReCo6502 second processor is set up to play ELITE at a manageable speed of 8.84MHz and it's playable whilst being lovely and smooth too.

To play at break neck speeds, disable the Linear Memory option as above and if it's not already running at 14.7MHz, choose B to run the ReCo6502 at full speed. I find that running ELITE at 14.7MHz is only playable if you have a digital joystick like a Competition Pro rather than the Acorn analogue joysticks as the Competition Pro makes docking a lot easier!

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