GaBuZoMeu wrote:
Hi Gordon,
using that socket should work perfectly. You only need to double check if your CAD has a correct definition of the socket and its pin numbers (their counting is somewhat special).
My CAD is ... Fritzing, which is/was OK for the basic 6502 board I've just done, however somewhat sub-optimal for this and it's probably time I learned KiCAD anyway.
GaBuZoMeu wrote:
In order to get it easy up and running you only need two crystals (32768 Hz and 3.6844 MHz) and a TTL<->USB Abdapter (ok, plus some C's). Then it should boot into the Mensch Monitor with 9600,8,N,1 IIRC.
Once you have your own monitor/bootloader/etc. in say a flash EPROM you can use faster clocks. I think I briefly tested 18.432 MHz (RAM only) with no issues. With a 55ns EPROM it runs hours @ 14.7456 MHz.
OK, thanks. My plan for my '816 project is to copy my existing 6502 project and have an ATmega share 256 bytes of RAM with the CPU (at $00FFxx), so with the '265, if I keep the '265 in reset, BE & Rdy low, poke the bootloader in, the shared RAM, then raise Rdy, BE and Reset in that order - which if I've interpreted the datasheet right puts the '265 core into what they call "emulation mode" which means no internal ROM/RAM decoding and full 24-bit external address bus then it ought to boot directly from RAM with no ROM needed.
GaBuZoMeu wrote:
Some additional information you may find at
New WDC W65C268QBX Board (pg.3++).
For additional I/O there are two /CS built in: /CS0 (32 byte) and /CS1 (64 byte). Both have a timing that corresponds to 65xx I/O (i.o.w /CS wents low during PHI1 and is released past end of PHI2). So it should be no issue to attach 2 VIAs with minimum efforts.
The /CS3..CS7 are gated with PHI2. This eases generating /WE and /RD for RAM/(E)EPROM.
Not sure I need any additional IO for my system - it "uses" 4 x 8-bit ports for the 24-bit address bus and 8-bit data bus in "emulation" mode, that's leaves 4 ports free - and as I only need 2 ports for my expansion plans, it leaves me with plenty in-hand.
It's making me wonder why more people aren't using this/talking about it and I feel I'm missing something, but maybe not and it's the fear of the unknown!
Thanks,
-Gordon
_________________
--
Gordon Henderson.
See my
Ruby 6502 and 65816 SBC projects here:
https://projects.drogon.net/ruby/