diff --git a/arch/z80/src/ez80/Toolchain.defs b/arch/z80/src/ez80/Toolchain.defs
index f869a56ef5..e4e319e7a0 100644
--- a/arch/z80/src/ez80/Toolchain.defs
+++ b/arch/z80/src/ez80/Toolchain.defs
@@ -107,14 +107,12 @@ endif
 # CPU Identification
 
 ifeq ($(CONFIG_ARCH_CHIP_EZ80F91),y)
-  ARCHCPU = eZ80F91
+  ARCHCPU    = eZ80F91
   ARCHCPUDEF = _EZ80F91
   ARCHFAMILY = _EZ80ACCLAIM!
 else ifeq ($(CONFIG_ARCH_CHIP_EZ80F92),y)
-  #ARCHCPU = eZ80F92
-  #ARCHCPUDEF = _EZ80F92
-  ARCHCPU = eZ80F91
-  ARCHCPUDEF = _EZ80F91
+  ARCHCPU    = eZ80F92
+  ARCHCPUDEF = _EZ80F92
   ARCHFAMILY = _EZ80ACCLAIM!
 endif
 
@@ -129,11 +127,9 @@ else
 endif
 
 ifeq ($(CONFIG_DEBUG_NOOPT),y)
-#  ARCHOPTIMIZATION += -promote -reduceopt -NOsdiopt
-  ARCHOPTIMIZATION += -NOsdiopt
+  ARCHOPTIMIZATION += -NOpromote -reduceopt -NOsdiopt
 else
-#  ARCHOPTIMIZATION += -NOpromote -NOreduceopt -sdiopt -optsize
-  ARCHOPTIMIZATION += -sdiopt
+  ARCHOPTIMIZATION += -promote -NOreduceopt -sdiopt -optsize
 endif
 
 # Tool names/paths.
diff --git a/boards/z80/ez80/ez80f910200kitg/scripts/Make.defs b/boards/z80/ez80/ez80f910200kitg/scripts/Make.defs
index ae25e7f385..27f4907106 100644
--- a/boards/z80/ez80/ez80f910200kitg/scripts/Make.defs
+++ b/boards/z80/ez80/ez80f910200kitg/scripts/Make.defs
@@ -63,7 +63,7 @@ AFLAGS = $(ARCHASMCPUFLAGS) $(ARCHASMINCLUDES) $(ARCHASMLIST) $(ARCHASMWARNINGS)
 # Compiler definitions
 
 ARCHCPUFLAGS = -chartype:S -promote -cpu:$(ARCHCPU) -NOgenprintf -NOmodsect \
-               -asmsw:" $(ARCHASMCPUFLAGS) $(EARCHASMINCLUDES) $(ARCHASMWARNINGS) $(ARCHOPTIMIZATION)"
+               -asmsw:" $(ARCHASMCPUFLAGS) $(EARCHASMINCLUDES) $(ARCHASMWARNINGS) $(ARCHASMOPTIMIZATION)"
 ARCHLIST = -keeplst -NOlist -NOlistinc -keepasm
 ARCHPICFLAGS =
 ARCHWARNINGS = -warn
diff --git a/boards/z80/ez80/ez80f910200zco/scripts/Make.defs b/boards/z80/ez80/ez80f910200zco/scripts/Make.defs
index b16713515e..0f4b15c6b1 100644
--- a/boards/z80/ez80/ez80f910200zco/scripts/Make.defs
+++ b/boards/z80/ez80/ez80f910200zco/scripts/Make.defs
@@ -63,7 +63,7 @@ AFLAGS = $(ARCHASMCPUFLAGS) $(ARCHASMINCLUDES) $(ARCHASMLIST) $(ARCHASMWARNINGS)
 # Compiler definitions
 
 ARCHCPUFLAGS = -chartype:S -promote -cpu:$(ARCHCPU) -NOgenprintf -NOmodsect \
-               -asmsw:" $(ARCHASMCPUFLAGS) $(EARCHASMINCLUDES) $(ARCHASMWARNINGS) $(ARCHOPTIMIZATION)"
+               -asmsw:" $(ARCHASMCPUFLAGS) $(EARCHASMINCLUDES) $(ARCHASMWARNINGS) $(ARCHASMOPTIMIZATION)"
 ARCHLIST = -keeplst -NOlist -NOlistinc -keepasm
 ARCHPICFLAGS =
 ARCHWARNINGS = -warn
diff --git a/boards/z80/ez80/makerlisp/scripts/Make.defs b/boards/z80/ez80/makerlisp/scripts/Make.defs
index c722657eae..b351ee7332 100644
--- a/boards/z80/ez80/makerlisp/scripts/Make.defs
+++ b/boards/z80/ez80/makerlisp/scripts/Make.defs
@@ -63,7 +63,7 @@ AFLAGS = $(ARCHASMCPUFLAGS) $(ARCHASMINCLUDES) $(ARCHASMLIST) $(ARCHASMWARNINGS)
 # Compiler definitions
 
 ARCHCPUFLAGS = -chartype:S -promote -cpu:$(ARCHCPU) -NOgenprintf -NOmodsect \
-               -asmsw:" $(ARCHASMCPUFLAGS) $(EARCHASMINCLUDES) $(ARCHASMWARNINGS) $(ARCHOPTIMIZATION)"
+               -asmsw:" $(ARCHASMCPUFLAGS) $(EARCHASMINCLUDES) $(ARCHASMWARNINGS) $(ARCHASMOPTIMIZATION)"
 ARCHLIST = -keeplst -NOlist -NOlistinc -keepasm
 ARCHPICFLAGS =
 ARCHWARNINGS = -warn
diff --git a/boards/z80/ez80/z20x/README.txt b/boards/z80/ez80/z20x/README.txt
index 09f6c27a0d..bae5957b5a 100644
--- a/boards/z80/ez80/z20x/README.txt
+++ b/boards/z80/ez80/z20x/README.txt
@@ -95,13 +95,6 @@ Memory Constaints
   you enable assertions, debug outputs, or even debug symbols.  It is very
   unlikely that the nsh_flash configuration will fit into FLASH at all!
 
-  I believe that there is some issue with the optimization CFLAGS used with
-  the ZDS-II compiler.  The size of the FLASH images that are generated are
-  larger than you would see with, say, an equivalent Cortex-M compilation.
-  I reviewed the individual object files.  There is not one thing that is
-  causing the large size.  Rather, the ZDS-II compiler is simply generating
-  larger CODE sections in the object files.
-
 Serial Console
 ==============
 
@@ -222,9 +215,12 @@ Configuration Subdirectories
     NOTES:
 
     1. UNVERIFIED!  I doubt that the nsh_flash program will fit into the
-       smaller FLASH memory of the eZ80F92 part.  See discusssion under
+       smaller FLASH memory of the eZ80F92 part.  See discussion under
        "Memory Constraints" above.
 
+       The nsh_ram configuration, of course, depends on the sdboot
+       bootloader to load that program into RAM.
+
     2. The two configurations different only in that one builds for
        execution entirely from FLASH and the other for execution entirely
        from RAM.  A bootloader of some kind is required to support such
@@ -349,3 +345,17 @@ Configuration Subdirectories
        64Kb of FLASH memory.  It will not be possible to run programs in
        SRAM *unless* some mechanism is developed to redirect interrupts
        from ROM and into loaded SRAM logic.
+
+       For example, it might be possible to implement this kind of
+       vectoring to get to a RAM based interrupt handler:
+
+       a. The initial 16-bit address in the interrupt vector table can
+          transfer the interrupt to a larger jump table also in lower
+          flash memory.
+       b. That jump table could vector to another jump table at a known
+          location RAM.
+       c. The RAM jump table could then jump to the final RAM-based
+          interrupt handler.
+
+       This would effect the logic in arch/z80/src/ez80/ez80f92_handlers.am
+       and possible the z20x *.linkcmd files.
diff --git a/boards/z80/ez80/z20x/scripts/Make.defs b/boards/z80/ez80/z20x/scripts/Make.defs
index dab450ea2f..71d9b08088 100644
--- a/boards/z80/ez80/z20x/scripts/Make.defs
+++ b/boards/z80/ez80/z20x/scripts/Make.defs
@@ -48,7 +48,7 @@ AFLAGS = $(ARCHASMCPUFLAGS) $(ARCHASMINCLUDES) $(ARCHASMLIST) $(ARCHASMWARNINGS)
 # Compiler definitions
 
 ARCHCPUFLAGS = -chartype:S -promote -cpu:$(ARCHCPU) -NOgenprintf -NOmodsect \
-               -asmsw:" $(ARCHASMCPUFLAGS) $(EARCHASMINCLUDES) $(ARCHASMWARNINGS) $(ARCHOPTIMIZATION)"
+               -asmsw:" $(ARCHASMCPUFLAGS) $(EARCHASMINCLUDES) $(ARCHASMWARNINGS) $(ARCHASMOPTIMIZATION)"
 ARCHLIST = -keeplst -NOlist -NOlistinc -keepasm
 ARCHPICFLAGS =
 ARCHWARNINGS = -warn