Hi,

   I am attaching a version of Zapple that works on my N8VEM V1
board.  I am running the Z80 at 6 MHz, and the SIO at 1.8432.
This version of the monitor is ORGed at 000H, so you would put it
in an EPROM, starting at 0.  The code is just under 2K bytes.
I am attaching the bin as well, but you should probably get
set up with TASM in case you want to change something.  There is
something called USER which is an address for user functions.
I don't think it's used, but in this version, I set it to
9000H, or 4K above the start of RAM.   Feel free to change it.
Zapple puts its variables and the stack at the top of available
RAM.  It doesn't seem to detect RAM that repeats, so if you have
a small RAM chip like I do (8K) Zapple will end up putting its
stuff way up at the top of the 64K space.  The ROM checksum should be
0724, if you type K0 7fff<CR>.  Also, this version is set up for
2400 baud.  Zapple can run much faster, but the code that parses
Intel hex files gets errors at 4800 from time to time if you are
using a 4 MHz Z80, so I just leave it at 2400 baud.  Probably UART
chips with receive FIFO's may solve that issue, but I haven't done
any testing.  If you need a Zapple manual, I can email the one I have.

Some commands are R<CR> read Intel hex into memory
D8000 8100 display memory
Z   show top of RAM
X   display and edit registers
K checksum memory (I added this)
G8000 jump to 8000 and execute
(this can have breakpoints as well if code is in RAM
there are also memory compare, memory move, and a few other cmds.

    Bob Grieb