My clone will support also turbo CPU mode. ULA/ASIC must read videodata and from same memory will CPU read/write data = we need faster sram chips. 16bit data bit enable reading two bytes in same time = 2x faster videodata reading = more free time for CPU in turbo mode. 16bit data bus is connect to CPLD only, Z80CPU are connect separately to same CPLD chip. Price of flash eprom 512kB is about 2-3 USD, this capacity of rom contain more rom images, custom menu, zx128 roms, divide systems, etc. PCB is designed for sram chips in TSSOP II 44 pins SMD sram chips - can be used 1x 512kB or 2x 512kB or 1x 1MB or 2x 1MB. For full info: clone can contain VL1772 and AY-3-8910 (if you connect chips to socket). Also internal ATOM IDE/DIVIDE ports, 2x SD card will used. More colors. Some features will used from my ZX project PROFI INTERFACE: http://velesoft.speccy.cz/profi/profi_interface_(5_11_2011)high_priority_techman.zip
VELESOFT ----- Original Message ----- From: Leslie Anderson To: [email protected] Sent: Sunday, March 24, 2013 7:05 PM Subject: Re: Sam Coupe project..making a real SAM in hardware ?? I'm looking at keeping my specification as simple ( and Cheap ) as possible. I'm assuming you're using a Z180 or Z280 to address 16Meg and have a 16 bit databus ?? My design will be as simple and hopefully easy as possible. I'm aiming to use about 10 low cost ICs. Z84C0020PEC DIP40 $2 K6T4008 or similar DIP32 $3.50 W27C512 EEPROM DIP28 <$1 EPM7128SLC84 CPLDs PLCC84 $3.50 each 2pcs V9958 Video IC DIP64 $4.50 HM62128 SRAM 128K Video RAM for V9958 SAA1099 PSG DIP18 Sound Chip MAX232 RS232 DIP16 RS232 driver Micro-controller DIP Atmel etc I should be able to get all these ICs for about $18...£14.50 or so Using so few ICs will also keep the board size down and running at 20MHz will make it about 4.5 times faster than the original SAM ! Also using CPLDs rather than discrete logic will give greater flexibility in the design. On 24 March 2013 17:45, Graeme Gregory <[email protected]> wrote: I better start piling the pennies into my Velesoft fund! That sounds like the ultimate speccy! Graeme On 24/03/13 16:50, VELESOFT wrote: I now work on my project SAM COUPE clone :-D Z80CPU 20MHz 2MB RAM (16bit fast data bus) 512kB FLASH EPROM CPLD chips as ASIC replacement and next features... SAA1099 soundchip System bus compatible with sam coupe ZX mode compatible with ZX128 VELESOFT ----- Original Message ----- From: Leslie Anderson To: [email protected] Sent: Sunday, March 24, 2013 3:28 PM Subject: Sam Coupe project..making a real SAM in hardware ?? 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
