Personally Id like to see big cheers for Colin and his continued support for the Sam :) Im just itching to get mine plugged in :D
Adrian -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Colin Piggot Sent: 14 July 2006 10:31 To: Adrian Subject: Mayhem Accelerator Update ( This is a cut down version of the article taken from the news in issue 15 of Sam Revival... ) Mayhem Accelerator Update ------------------------- Fantastic news because the long awaited prototype of the Mayhem Accelerator is now complete! Of course there have been ups and downs along the way, including something going 'pop' while I was testing the last piece of circuitry that I mentioned in the last issue! Yes, I had blown the prototype, not sure how and it wasn't a fault I could easily trace, it's not the first major fault during it's long development, but when so close to completion it was a disappointment. The prototype was already in a pretty fragile state as a lot of it was held together by thin wires for quickness as more and more modules had been added over time and dismantling parts to investigate the problem often resulted in repairing broken links. Not to be put off, I decided to rebuild a new prototype from scratch instead of wasting time trying to trace what I had blown. Over the next few days at the end of May I have a new prototype built up and working at near enough the level I was at before. Luckily I still had some unused PCBs for the main sections which I had etched back in 2004, and rebuilt all the other sections on stripboard as before. Even though, I was building this up at lightning pace I was doing so much more robustly with neater layouts, shorter links, more secure wiring etc. It also gave me the opportunity to build up some of the modules with several design revisions implemented and new features, something I hadn't planned to do until I was preparing the final PCB layouts for the production version. One of the new additions I've added into the design of the Mayhem is that it now features a 6MHz 'legacy' mode, so you can run it at the normal 6MHz speed with contended memory to save you having to unplug the interface to use the Sam at it's original speed. The other speed options remain at 10MHz, 16MHz and 20MHz, with a push button to cycle through the frequencies, with the current selection indicated by a coloured LED on the Mayhem itself, and also on the Sam's startup screen. On the 9th of June I was able to declare the prototype of the Mayhem Accelerator complete, with the design 100% complete and operational. It's beena long journey and it was great to be able to finally say that! With the design complete, here are the final benchmarks for the Mayhem Accelerator... Fractal Explorer (generating the default Mandlebrot image) Normal Sam: 21.30 seconds Mayhem @ 10MHz: 10.56 seconds (202% speedup) Mayhem @ 16MHz: 7.20 seconds (296% speedup) Mayhem @ 20MHz: 6.06 seconds (352% speedup) BogoMIPS Normal Sam: 0.360 BogoMIPS M @ 10MHz: 0.748 BogoMIPS (208% speedup) M @ 16MHz: 1.208 BogoMIPS (336% speedup) M @ 20MHz: 1.513 BogoMIPS (420% speedup) Pushing the Sam beyond it's 6MHz speed is all uncharted territory for how software reacts, but i've been having a great time using it over the last few months in particular with old games! As well as running old software faster, one great aspect of the Mayhem Accelerator is for new software, just think what can now be achieved with a faster Sam Coupé, stay tuned to Sam Revival magazine for details of software written with the Mayhem Accelerator in mind from both myself and other programmers. So, what's left. I'm in the process of designing the PCBs for the production version of the Mayhem Accelerator, and hope to have the first set etched for testing by the end of July. Once I have a Mayhem built up on the final PCBs, i'll be going through the whole testing procedure again. Then once tested I'll be ordering a full batch of PCBs and building up the first lot of Mayhem Accelerators, with the aim to have them out as soon as possible. The question I've been asked most is what is the price going to be? Pricing can always be controversial in some peoples' eyes and it is something that I do occasionally receive undue criticism over. Right from the start when I first released the Quazar Surround soundcard in 1995 I received letters saying the price at the time was too high, and how I must sell it to them for a cheaper amount despite them not realising just how much it actually cost to build, or what it had cost to develop and release. Unfortunately, unless you are actually involved in hardware development, it's not easy to explain to people about how quickly costs can escalate. But they can! So I'm being open with regards to what it's personally cost me to develop the Mayhem Accelerator. It is safe to say that this has been my biggest Sam Coupé project to date over the 11 years that i've been working on the Sam - with it's development spanning two and a half years on and off. Doing some quick sums it adds up to an estimated £3350 development cost by the time the first production units are ready if everything such as parts, test equipment and design software is included in the bill. The oscilloscope mentioned in the 'Creating Mayhem' article in issue 12 of Sam Revival which I bought for hardware debugging cost £1500 by itself. Of course test equipment is useful for other projects i've got on the go, but still they were initially required for the Mayhem's design phases. It's a good job I don't charge myself an hourly rate for time! So at this stage I am now ready to announce the pricing for the Mayhem Accelerator, and plan ahead for the first batch to be ready to ship out in mid August. The Mayhem Accelerator will cost £139.99, including Special Delivery postage in the UK. For delivery to EU countries there will be an additional £5.50 to cover the extra required for insured international delivery. I am planning to put together a large 'FAQ' (Frequently Asked Questions) list in the next issue of Sam Revival so if any you have any questions whatsoever with regards to the Mayhem Accelerator do please feel free to get in touch directly. Colin ===== Quazar : Hardware, Software, Spares and Repairs for the Sam Coupe April 1995-2006 - Celebrating 11 Years of developing for the Sam Coupe Website: http://www.samcoupe.com/
