Run a Z80 CPU at up to 20MhzDesigned by Dino Boards in Australia
A Z80 CPU module supporting speeds up to 20Mhz - but with the required wait states and clock control to ensure compatibility with existing software and RC2014 modules. What is it? This module is desi…Read More…
A Z80 CPU module supporting speeds up to 20Mhz - but with the required wait states and clock control to ensure compatibility with existing software and RC2014 modules.
This module is designed to replace your existing RC2014 CPU and Clock Modules and give you the full power of a Z80 running at 20Mhz, yet still be broadly compatible with original software and your other RC2014 modules.
For a RC2014 configured to run a full MSX configuration, you typically need to run your CPU at just 3.5Mhz, as software written for the platform at the time, would assume your system was clocked at this speed. If you attempt to run programs at a higher cpu clock speed, you will probably get video corruption, I/O problems -- it just wont work!.
But these days, its possible to buy a brand new Zilog Z80 chip, rated at 20Mhz (Z84C0020PEG). For me in the mid 80s, that would have been an unimaginable speed!
We achieve compatibility by applying a combination of hardware wait states (pausing the CPU for a bit) and automatically slowing the clock down to the 3.5Mhz for short periods of time when the CPU is interacting with your other modules.
A 3 way slider, soldered on the front of the module, gives you total control of the CPU speed. Using this switch, you can at any time switch into 1 of 3 modes:
Despite the extra wait states and clock slow down, I have found a typical speed improvement of between 4 and 5 times faster - even for software the does lots of interactions with the V9958, you can still see a very large improvement.
These are a series of boards that I am developing to achieve MSX compatibility for RC2014 systems.
The idea is that you can build each board one at a time, test it and play with it under RomWBW - and then once you have the set - load up some MSX/MSX2+ games!
The V9958 board is the first in that series.
More details can be found on my hackaday project
The full kits includes everything you need (PCB, capacitors, IC sockets, connectors, and the ICs). The 2 PLD chips are flashed with logic to control the wait and clock slow down logic.
Also included is a 20Mhz and an alternative 16Mhz oscillator.
I have tested running at 20Mhz on my specific back-plane and set of modules without any problems. But due to differences in combination and configuration of RC2014 kits - you may find with your specific situation, there are signal degradation issues at 20Mhz that may cause non-reliable operation. With the supplied 16Mhz alternative oscillator, you should be able to achieve good operation, but at a slightly lower speed.
|2||470 Ω (3.4mm)|
|1||10k Ω Bussed x 6|
|1||SP3T Slide Switch|
|1||16 Mhz Oscillator|
|1||20 Mhz Oscillator|
|1||7.3728 Mhz Crystal|
|2||Right Angle 20x2 Header|
|1||40 POS IC SOCKET|
|1||24 POS IC SOCKET NARROW|
|1||20 POS IC SOCKET|
|1||16 POS IC SOCKET|
|4||14 POS IC SOCKET|
|1||8 POS IC SOCKET|
You need a RC2014 build. This can be configured with MSX modules or other modules.
I have tested on a conventional RC2014 build and with the MSX Modules.
This modules replaces your RC2014 CPU and Clock Modules.
Please note that this is a kit, produced by a non-professional (me) for hackers, DIYers' and retro lovers, to tinker with. I will do my best to answer any support questions you may have.
No country selected, please select your country to see shipping options.
No rates are available for shipping to .
Enter your email address if you'd like to be notified when Turbo CPU Module Designed for RC2014 can be shipped to you:
Thanks! We'll let you know when the seller adds shipping rates for your country.
|Shipping Rate||Tracked||Ships From||First Item||Additional Items|
We recognize our top users by making them a Tindarian. Tindarians have access to secret & unreleased features.
We look for the most active & best members of the Tindie community, and invite them to join. There isn't a selection process or form to fill out. The only way to become a Tindarian is by being a nice & active member of the Tindie community!