Several frequencies could be software selectable , 3.58MHz,6MHz, up to 20MHz..in theory, simply by halting the CPU then switching crystal input frequency. But it's early days... still got to design it !
If anyone is interested in helping .... then just let me know ..! On 24 March 2013 18:41, VELESOFT <[email protected]> wrote: > Yes. Now I plan all modes fast/uncontended. Perfect memory contention > timing will add in 6MHz mode later. > > VELESOFT > > ----- Original Message ----- From: "Simon Owen" <[email protected]> > To: <[email protected]> > Sent: Sunday, March 24, 2013 7:28 PM > > Subject: Re: Sam Coupe project..making a real SAM in hardware ?? > > > Will any clones still have a 6MHz mode, with memory timings identical to >> the original hardware? A higher proportion of SAM software depends on >> them for video effects, compared to what you'd see on the Spectrum. >> >> Si >> >> On 24/03/2013 14:28, Leslie Anderson wrote: >> >>> Hi. >>> >>> I'm new to the SAM COUPE group and wondered would anyone be interested >>> in making a homebrew SAM-COUPE ?? >>> >>> It would have an improved spec. on the original: >>> >>> Z84C0020 20MHz Z80 >>> 512K SRAM ( KM68400,K6T4008 etc) >>> 64K or so EEPROM W27C512 >>> CPLDs as glue logic for video, memory and I/O decoding, serial and >>> parallel input,output RS232, LPT1 etc >>> SAA1099 sound chip >>> V9958 +128K RAM as second VDP for sprites etc >>> possible using a micro-controller for PS/2 mouse / keyboard and >>> joystick input. >>> >>> Should cost about £30 for ICs and stuff plus another £50 for a one-of >>> prototype PCB. >>> >>> Anyone interested ?? >>> >>> Best Regards >>> >> >> >
