Apple II's system monitor

The monitor allows peeking and poking memory in a manner that is
much more convenient than with BASIC, in hexadecimal notation.

A complete reference is in "Apple IIe Reference Manual". This is
a quick reference.

When inside BASIC, we enter the monitor with "CALL -151". We
then get a "*" prompt.

Typing an address reads that byte:

*1DFC
1DFC- 2A
*

We can fetch a range:

*1DFC.1E00
1DFC- 2A 2B 2C 2D
1E00- 2E
*

We can set memory:

*1DFC:01 02 03
*1DFC.1E00
1DFC- 01 02 03 2D
1E00- 2E
*

We can "continue" setting memory, omitting address:

*1DFC:04 05 06
*:07 08
*1DFC.1E00
1DFC- 04 05 06 07
1E00- 08
*

You can disassemble memory with "L" (for LIST):

*1DFCL
(20 lines of disassembled memory)