Hey Gary,
Actually, thinking about it, even generating the WR signal shouldn't be
an issue. I could just detect CE active with no RD at the proper
location. This would be really easy.
Trying to decode the opcodes to generate WR is complicated by the fact
that the opcodes produce varying numbers of RD and WR cycles. For
instace, MOV M,A only generates a single write cycle after the opcode
fetch, but CALL 3000h would generate 2 read cycles (to get the call
address) followed by 2 write cycles (to save the current PC to the stack).
Ken
On 7/26/17 3:35 PM, Gary Weber wrote:
Ken,
While the NEC "All Ram" mode is as easy as copying whatever contents
you want into "Bank2 RAM" and flipping a few bits on an OUT port to
MAP bank #2 into ROM #0 address space, it seems your planned solution
for the M100 may indeed also be very interesting for the NEC in spite
of that convenience. The reason is the Wifi/Flash/REX
functionality. I don't suppose you would consider a slight tweak to
the design to support the NEC eventually? I know the lack of the ALE
signal on the NEC's socket led to some tricky logic that Steve had to
do in REX3, and I was hoping that might be possible here too.
I'm definitely interested in experimenting with CP/M on the NEC and
will explore that with just the regular all RAM mode of course, but
having a dedicated hardware solution that could provide main system
RAM as well as full option ROM capability (like REX) would kind of
revolutionize things a bit.
Speaking of CP/M: @Philip, might you be able to pass me the source
image to which I can make the necessary tweaks for the NEC PC-8201A &
8300?
Gary Weber
www.web8201.net <http://www.web8201.net>
(and soon to be www.web8201.com <http://www.web8201.com>!)
On Mon, Jul 24, 2017 at 10:10 AM, Mark J. Blair <n...@nf6x.net
<mailto:n...@nf6x.net>> wrote:
On Jul 24, 2017, at 10:03, Ken Pettit <petti...@gmail.com
<mailto:petti...@gmail.com>> wrote:
I was looking at using the ATWINC1500 module. This is WiFi only
and no Bluetooth. The module is *just* small enough that it can
fit on a PCB within the OptROM socket, provided it is a stacked
PCB on top of the main Woolly PCB.
Wow, that little guy is even smaller than the ESP-WROOM-32 module!
--
Mark J. Blair, NF6X <n...@nf6x.net <mailto:n...@nf6x.net>>
http://www.nf6x.net/
