Slight improvements to doc, reduce base DRAM size for cb030

Author: none

README.md

@@ -1,40 +1,64 @@
 # py68k
+
 M68K emulator based on Musashi, with a Python device model
 
 ## running
-Launch the console server with `py68k.py --console-server`. This provides vt102 terminal emulation for the console serial port. The console server will stay alive across multiple runs of the emulator.
 
-Launch the emulator itself with `py68k.py --target <target-name> [<target-options>]`. You can pass
-`--help` with or without `--target`; if passed with, additional target-specific help may be printed.
+Launch the console server with `py68k.py --console-server`. This provides vt102
+terminal emulation for the console serial port. The console server will stay
+alive across multiple runs of the emulator.
+
+Launch the emulator itself with `py68k.py --target <target-name>
+[<target-options>]`. You can pass `--help` with or without `--target`; if
+passed with, additional target-specific help may be printed.
 
 ## emulations
-py68k has a flexible device and target model that makes supporting new targets relatively easy.
 
-See `devices/` for some device examples, and `targets/` for corresponding targets.
+py68k has a flexible device and target model that makes supporting new targets
+relatively easy.
+
+See `devices/` for some device examples, and `targets/` for corresponding
+targets.
 
 ### simple
-The `simple` target is primarily for emulator testing, though being very simple it's also a good
-target for hosting software development. See `devices/simple.py` and `targets/simple.py`.
+
+The `simple` target is primarily for emulator testing, though being very simple
+it's also a good target for hosting software development. See
+`devices/simple.py` and `targets/simple.py`.
 
 ### Tiny68k
-Bill Shen's Tiny68k is a 68000 board with 16M of RAM and a 68681:
+
+Bill Shen's Tiny68k is a 68000 board with 16M of RAM and a 68681. The emulator
+supports the rev2 board:
 
 https://www.retrobrewcomputers.org/doku.php?id=boards:sbc:tiny68k:tiny68k_rev2
 
-Fetch the Tiny68K monitor / debugger image and CF CP/M image and run:
+Additional resources including CP/M images can be found on the rev1 page:
+
+https://www.retrobrewcomputers.org/doku.php?id=boards:sbc:tiny68k
+
+Fetch the Tiny68K monitor / debugger for v2 and CF CP/M disk image and run:
 
 `./py68k.py --target tiny68k --diskfile t68k_cpm_disk.bin --eeprom T68kbug_r07.BIN`
 
-### P90MB
-Bill Shen's P90MB features a Philips P90CE201 68070-based system-on-chip, 512k of flash,
-512k of RAM, I2C and three RC2014 slots.
+### P90MB (WIP)
+
+Bill Shen's P90MB features a Philips P90CE201 68070-based system-on-chip, 512k
+of flash, 512k of RAM, I2C and three RC2014 slots.
 
 https://www.retrobrewcomputers.org/doku.php?id=builderpages:plasmo:p90mb
 
 Fetch the EPROM file with monitor, CP/M and BASIC, and run:
 
 `./py68k --target p90mb --rom loader1_5+EhBasic+CPM.BIN`
 
+### CB030 (WIP)
+
+Another Bill Shen board, CB030 is a minimal 68030 system.
+
+This emulation has some serious issues due to limitations in Musashi's MMU 
+emulation.
+
 ## Requirements
 
 Python, with vt102, pyelftools and hexdump modules installed.

targets/cb030.py

@@ -11,7 +11,7 @@ def add_arguments(parser):
                         help='ROM image')
     parser.add_argument('--dram-size',
                         type=int,
-                        default=64,
+                        default=16,
                         help='DRAM size; boards may have 16, 64 or 128M')
     parser.add_argument('--cf-width',
                         type=int,