From 09e50d433da2354b91fab27b4eb1ddaee69c87dc Mon Sep 17 00:00:00 2001
From: Greg King <gregdk@users.sf.net>
Date: Sun, 9 Nov 2014 06:32:11 -0500
Subject: [PATCH 1/8] * Changed the way that Atmos programs are started.
- Put a BASIC-language stub at the beginning.
- Removed the Autostart flag.
Those changes make it easy to give command-line arguments to a program.
* Made the Atmos configure file accept a special symbol definition on ld65's command line. We can use "__RAMEND__" to increase the amount of RAM that's available to programs.
---
cfg/atmos.cfg | 20 +++++++++++-----
doc/atmos.sgml | 52 +++++++++++++++++++++++++++++-------------
libsrc/atmos/bashdr.s | 24 +++++++++++++++++++
libsrc/atmos/crt0.s | 37 ++++++++++--------------------
libsrc/atmos/tapehdr.s | 30 ++++++++++++++++++++++++
5 files changed, 116 insertions(+), 47 deletions(-)
create mode 100644 libsrc/atmos/bashdr.s
create mode 100644 libsrc/atmos/tapehdr.s
diff --git a/cfg/atmos.cfg b/cfg/atmos.cfg
index 137c0e9a9..062711b96 100644
--- a/cfg/atmos.cfg
+++ b/cfg/atmos.cfg
@@ -1,22 +1,30 @@
SYMBOLS {
- __STACKSIZE__: type = weak, value = $0800; # 2k stack
+ __TAPEHDR__: type = import;
+ __BASHDR__: type = import;
+ __PROGFLAG__: type = weak, value = $00; # $00=BASIC, $80=machine code
+ __AUTORUN__: type = weak, value = $00; # $C7=run, $00=only load
+ __STACKSIZE__: type = weak, value = $0800; # 2K stack
+ __RAMEND__: type = weak, value = $9800; # graphics RAM not grabbed
+# __RAMEND__: type = weak, value = $B400; # graphics RAM grabbed
}
MEMORY {
ZP: file = "", define = yes, start = $00E2, size = $001A;
- TAPEHDR: file = %O, type = ro, start = $0000, size = $0011;
- RAM: file = %O, define = yes, start = $0500, size = $9300 - __STACKSIZE__;
+ TAPEHDR: file = %O, type = ro, start = $0000, size = $001F;
+ BASHEAD: file = %O, define = yes, start = $0501, size = $000D;
+ RAM: file = %O, define = yes, start = __BASHEAD_LAST__, size = __RAMEND__ - __RAM_START__ - __STACKSIZE__;
}
SEGMENTS {
+ ZEROPAGE: load = ZP, type = zp;
TAPEHDR: load = TAPEHDR, type = ro;
+ BASHDR: load = BASHEAD, type = ro, define = yes, optional = yes;
STARTUP: load = RAM, type = ro;
LOWCODE: load = RAM, type = ro, optional = yes;
- INIT: load = RAM, type = ro, define = yes, optional = yes;
CODE: load = RAM, type = ro;
RODATA: load = RAM, type = ro;
+ INIT: load = RAM, type = ro, define = yes, optional = yes;
DATA: load = RAM, type = rw;
- ZPSAVE: load = RAM, type = bss, define = yes;
+ ZPSAVE: load = RAM, type = rw, define = yes;
BSS: load = RAM, type = bss, define = yes;
- ZEROPAGE: load = ZP, type = zp;
}
FEATURES {
CONDES: type = constructor,
diff --git a/doc/atmos.sgml b/doc/atmos.sgml
index 805fc7a03..ab63c667b 100644
--- a/doc/atmos.sgml
+++ b/doc/atmos.sgml
@@ -7,7 +7,7 @@
<url url="mailto:uz@cc65.org" name="Ullrich von Bassewitz">,<newline>
<url url="mailto:polluks@sdf.lonestar.org" name="Stefan A. Haubenthal">,<newline>
<url url="mailto:greg.king5@verizon.net" name="Greg King">
-<date>2014-03-27
+<date>2014-09-23
<abstract>
An overview over the Atmos runtime system as it is implemented for the cc65 C
@@ -32,27 +32,37 @@ more than one platform. Please see the function reference for more
information.
+
<sect>Binary format<p>
The standard binary output format generated by the linker for the Atmos target
-is a machine language program with a 17 byte tape header including a cc65 tag.
-The standard load and autostart address is $500.
+is a machine language program with a one-line BASIC stub that jumps to the
+machine-language part through <tt/CALL/. It has a 24-byte tape header.
+It means that a file can be loaded as a BASIC program, and started with RUN.
+The standard load address is $501.
+
<sect>Memory layout<p>
-In the standard setup, cc65 generated programs use the memory from
-$500 to $9800, so nearly 37K of memory (including the stack) is
+In the standard setup, cc65-generated programs use the memory from
+$0501 to $9800; so, nearly 37K of memory (including the stack) is
available. ROM calls are possible without further precautions.
+If your program needs more memory, and it won't use TGI graphics, then you can
+use the ld65 command-line option, <tt/-D __RAMEND__=$B400/, when building the
+program, to "grab" the graphics screen RAM. Then, nearly 44K of memory is
+available.
+
Special locations:
<descrip>
<tag/Stack/
- The C runtime stack is located at $97FF and growing downwards.
+ The C runtime stack is located at $97FF (or $B3FF), and grows
+ downwards.
<tag/Heap/
- The C heap is located at the end of the program and grows towards the C
+ The C heap is located at the end of the program, and grows towards the C
runtime stack.
</descrip><p>
@@ -117,7 +127,8 @@ The names in the parentheses denote the symbols to be used for static linking of
<sect1>Graphics drivers<p>
-The default drivers, <tt/tgi_stddrv (tgi_static_stddrv)/, point to <tt/atmos-240-200-2.tgi (atmos_240_200_2_tgi)/.
+The default drivers, <tt/tgi_stddrv (tgi_static_stddrv)/,
+point to <tt/atmos-240-200-2.tgi (atmos_240_200_2_tgi)/.
<descrip>
@@ -175,13 +186,14 @@ No mouse drivers are currently available for the Atmos.
<sect1>Disk I/O<p>
-The existing library for the Atmos doesn't implement C file
-I/O. There are hacks for the <tt/read()/ and <tt/write()/ routines in
-place, which will make functions work that read from and write to <tt/stdout/
-(like <tt/printf()/). However, those functions have some shortcomings which
-won't be fixed, because they're going to be replaced anyway.
+The existing library for the Atmos doesn't implement C file I/O. There are
+hacks for the <tt/read()/ and <tt/write()/ routines in place, which will make
+functions work that read from <tt/stdin/ and write to <tt/stdout/ and
+<tt/stderr/ (such as <tt/printf()/). However, those functions have some
+shortcomings which won't be fixed, because they're going to be replaced
+anyway.
-To be more concrete, the limitation means that you cannot use any of the
+To be more concrete, that limitation means that you cannot use any of the
following functions (and a few others):
<itemize>
@@ -202,7 +214,13 @@ following functions (and a few others):
<sect1>Function keys<p>
-These are defined to be FUNCT + number key.
+They are defined to be FUNCT + a number key.
+
+
+<sect1>Capitals Lock<p>
+
+The "CAPS Lock" mode is turned off while the program is running. The previous
+mode (usually turned on) is restored when the program stops.
<sect1>Passing arguments to the program<p>
@@ -211,10 +229,12 @@ Command-line arguments can be passed to <tt/main()/. Since that is not
supported directly by BASIC, the following syntax was chosen:
<tscreen><verb>
- CALL#500:REM ARG1 " ARG2 IS QUOTED" ARG3 "" ARG5
+ RUN:REM arg1 " ARG2 IS QUOTED" ARG3 "" ARG5
</verb></tscreen>
<enum>
+<item>You must turn <tt/CAPS/ lock off (tap CTRL-T) when you want to type
+ lower-case arguments.
<item>Arguments are separated by spaces.
<item>Arguments may be quoted.
<item>Leading and trailing spaces around an argument are ignored. Spaces within
diff --git a/libsrc/atmos/bashdr.s b/libsrc/atmos/bashdr.s
new file mode 100644
index 000000000..e09bc9fec
--- /dev/null
+++ b/libsrc/atmos/bashdr.s
@@ -0,0 +1,24 @@
+;
+; 2010-11-14, Ullrich von Bassewitz
+; 2014-09-06, Greg King
+;
+; This module supplies a small BASIC stub program that uses CALL
+; to jump to the machine-language code that follows it.
+;
+
+ ; The following symbol is used by the linker config. file
+ ; to force this module to be included into the output file.
+ .export __BASHDR__:abs = 1
+
+
+.segment "BASHDR"
+
+ .addr Next
+ .word .version ; Line number
+ .byte $BF,'#' ; CALL token, mark number as hexadecimal
+ .byte <(Start >> 8 ) + '0' + (Start >> 8 > $09) * $07
+ .byte <(Start >> 4 & $0F) + '0' + (Start >> 4 & $0F > $09) * $07
+ .byte <(Start & $0F) + '0' + (Start & $0F > $09) * $07
+ .byte $00 ; End of BASIC line
+Next: .addr $0000 ; BASIC program end marker
+Start:
diff --git a/libsrc/atmos/crt0.s b/libsrc/atmos/crt0.s
index 1d919f348..63961bfe8 100644
--- a/libsrc/atmos/crt0.s
+++ b/libsrc/atmos/crt0.s
@@ -2,39 +2,18 @@
; Startup code for cc65 (Oric version)
;
; By Debrune J�r�me <jede@oric.org> and Ullrich von Bassewitz <uz@cc65.org>
-; 2014-08-22, Greg King
+; 2014-11-09, Greg King
;
.export _exit
.export __STARTUP__ : absolute = 1 ; Mark as startup
.import initlib, donelib
.import callmain, zerobss
- .import __RAM_START__, __RAM_SIZE__
- .import __ZPSAVE_LOAD__, __STACKSIZE__
+ .import __RAM_START__, __RAM_SIZE__, __STACKSIZE__
.include "zeropage.inc"
.include "atmos.inc"
-; ------------------------------------------------------------------------
-; Oric tape header
-
-.segment "TAPEHDR"
-
- .byte $16, $16, $16 ; Sync bytes
- .byte $24 ; End of header marker
-
- .byte $00 ; $2B0
- .byte $00 ; $2AF
- .byte $80 ; $2AE Machine code flag
- .byte $C7 ; $2AD Autoload flag
- .dbyt __ZPSAVE_LOAD__ - 1 ; $2AB
- .dbyt __RAM_START__ ; $2A9
- .byte $00 ; $2A8
- .byte ((.VERSION >> 8) & $0F) + '0'
- .byte ((.VERSION >> 4) & $0F) + '0'
- .byte (.VERSION & $0F) + '0'
- .byte $00 ; Zero terminated compiler version
-
; ------------------------------------------------------------------------
; Place the startup code in a special segment.
@@ -79,7 +58,7 @@ L1: lda sp,x
; Call the module destructors. This is also the exit() entry.
-_exit: jsr donelib ; Run module destructors
+_exit: jsr donelib
; Restore the system stuff.
@@ -104,7 +83,15 @@ L2: lda zpsave,x
.segment "ZPSAVE"
-zpsave: .res zpspace
+zpsave:
+
+; This padding is needed by a bug in the ROM.
+; (The CLOAD command starts BASIC's variables table on top of the last byte
+; that was loaded [instead of at the next address].)
+
+ .byte 0
+
+ .res zpspace - 1
; ------------------------------------------------------------------------
diff --git a/libsrc/atmos/tapehdr.s b/libsrc/atmos/tapehdr.s
new file mode 100644
index 000000000..b8562eb02
--- /dev/null
+++ b/libsrc/atmos/tapehdr.s
@@ -0,0 +1,30 @@
+;
+; Based on code by Debrune J�r�me <jede@oric.org>
+; 2013-08-15, Greg King
+;
+
+ ; The following symbol is used by the linker config. file
+ ; to force this module to be included into the output file.
+ .export __TAPEHDR__:abs = 1
+
+ .import __BASHDR_LOAD__, __ZPSAVE_LOAD__, __AUTORUN__, __PROGFLAG__
+
+
+; ------------------------------------------------------------------------
+; Oric cassette-tape header
+
+.segment "TAPEHDR"
+
+ .byte $16, $16, $16 ; Sync bytes
+ .byte $24 ; Beginning-of-header marker
+
+ .byte $00 ; $2B0
+ .byte $00 ; $2AF
+ .byte <__PROGFLAG__ ; $2AE Language flag ($00=BASIC, $80=machine code)
+ .byte <__AUTORUN__ ; $2AD Auto-run flag ($C7=run, $00=only load)
+ .dbyt __ZPSAVE_LOAD__ ; $2AB Address of end of file
+ .dbyt __BASHDR_LOAD__ ; $2A9 Address of start of file
+ .byte $00 ; $2A8
+
+ ; File name (a maximum of 17 characters), zero-terminated
+ .asciiz .sprintf("%u", .time)
From 8d5bb552818ec7b52426be223e1c1ab837021147 Mon Sep 17 00:00:00 2001
From: Greg King <gregdk@users.sf.net>
Date: Wed, 3 Dec 2014 12:02:48 -0500
Subject: [PATCH 2/8] Made some descriptions less ambiguous.
---
doc/atmos.sgml | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/doc/atmos.sgml b/doc/atmos.sgml
index ab63c667b..a9d59a407 100644
--- a/doc/atmos.sgml
+++ b/doc/atmos.sgml
@@ -7,7 +7,7 @@
<url url="mailto:uz@cc65.org" name="Ullrich von Bassewitz">,<newline>
<url url="mailto:polluks@sdf.lonestar.org" name="Stefan A. Haubenthal">,<newline>
<url url="mailto:greg.king5@verizon.net" name="Greg King">
-<date>2014-09-23
+<date>2014-12-03
<abstract>
An overview over the Atmos runtime system as it is implemented for the cc65 C
@@ -219,8 +219,9 @@ They are defined to be FUNCT + a number key.
<sect1>Capitals Lock<p>
-The "CAPS Lock" mode is turned off while the program is running. The previous
-mode (usually turned on) is restored when the program stops.
+The keyboard's "CAPS Lock" mode is turned off while the program is running.
+The previous mode (usually, CAPS Lock turned on [because Oric BASIC keywords
+must be UPPER-case]) is restored when the program stops.
<sect1>Passing arguments to the program<p>
@@ -234,7 +235,7 @@ supported directly by BASIC, the following syntax was chosen:
<enum>
<item>You must turn <tt/CAPS/ lock off (tap CTRL-T) when you want to type
- lower-case arguments.
+ lower-case arguments (but, <tt/RUN/ and <tt/REM/ must be UPPER-case).
<item>Arguments are separated by spaces.
<item>Arguments may be quoted.
<item>Leading and trailing spaces around an argument are ignored. Spaces within
From d9df576fa6e894a2d6321084dd5423549b5176ba Mon Sep 17 00:00:00 2001
From: Greg King <gregdk@users.sf.net>
Date: Sat, 13 Dec 2014 09:52:39 -0500
Subject: [PATCH 3/8] Used an easier-to-remember way of creating a program that
uses graphics RAM for other purposes.
---
cfg/atmos.cfg | 6 +++---
doc/atmos.sgml | 21 +++++++++++++++------
2 files changed, 18 insertions(+), 9 deletions(-)
diff --git a/cfg/atmos.cfg b/cfg/atmos.cfg
index 062711b96..691bd467d 100644
--- a/cfg/atmos.cfg
+++ b/cfg/atmos.cfg
@@ -2,10 +2,10 @@ SYMBOLS {
__TAPEHDR__: type = import;
__BASHDR__: type = import;
__PROGFLAG__: type = weak, value = $00; # $00=BASIC, $80=machine code
- __AUTORUN__: type = weak, value = $00; # $C7=run, $00=only load
+ __AUTORUN__: type = weak, value = $00; # $00=only load, $C7=run
__STACKSIZE__: type = weak, value = $0800; # 2K stack
- __RAMEND__: type = weak, value = $9800; # graphics RAM not grabbed
-# __RAMEND__: type = weak, value = $B400; # graphics RAM grabbed
+ __GRAB__: type = weak, value = 0; # 0=don't grab graphics RAM, 1=grab graphics RAM
+ __RAMEND__: type = weak, value = $9800 + $1C00 * __GRAB__;
}
MEMORY {
ZP: file = "", define = yes, start = $00E2, size = $001A;
diff --git a/doc/atmos.sgml b/doc/atmos.sgml
index a9d59a407..913e50ed7 100644
--- a/doc/atmos.sgml
+++ b/doc/atmos.sgml
@@ -7,7 +7,7 @@
<url url="mailto:uz@cc65.org" name="Ullrich von Bassewitz">,<newline>
<url url="mailto:polluks@sdf.lonestar.org" name="Stefan A. Haubenthal">,<newline>
<url url="mailto:greg.king5@verizon.net" name="Greg King">
-<date>2014-12-03
+<date>2014-12-05
<abstract>
An overview over the Atmos runtime system as it is implemented for the cc65 C
@@ -50,9 +50,9 @@ In the standard setup, cc65-generated programs use the memory from
available. ROM calls are possible without further precautions.
If your program needs more memory, and it won't use TGI graphics, then you can
-use the ld65 command-line option, <tt/-D __RAMEND__=$B400/, when building the
-program, to "grab" the graphics screen RAM. Then, nearly 44K of memory is
-available.
+use the ld65 command-line option, <tt/-D __GRAB__=1/, when building the
+program, to include the graphics screen RAM. Then, nearly 44K of memory
+($0501 to $B400) is available.
Special locations:
@@ -100,7 +100,7 @@ structures; accessing the struct fields will access the chip registers.
<descrip>
<tag><tt/VIA/</tag>
- Access to the VIA (versatile interface adapter) chip is available via the
+ Access to the VIA (Versatile Interface Adapter) chip is available via the
<tt/VIA/ variable. The structure behind this variable is explained in <tt/_6522.h/.
</descrip><p>
@@ -217,7 +217,7 @@ following functions (and a few others):
They are defined to be FUNCT + a number key.
-<sect1>Capitals Lock<p>
+<sect1>Capitals lock<p>
The keyboard's "CAPS Lock" mode is turned off while the program is running.
The previous mode (usually, CAPS Lock turned on [because Oric BASIC keywords
@@ -246,6 +246,15 @@ supported directly by BASIC, the following syntax was chosen:
</enum>
+<sect1>Automatic starting<p>
+
+Usually, a cc65-built program just will sit quietly in memory, after it is
+CLOADed. It waits for you to start it (by typing BASIC's <tt/RUN/ command).
+But, if you want to create a program that will start running immediately after
+it is loaded, then you can use the linker command-line option
+<tt/-D __AUTORUN__=$C7/.
+
+
<sect1>Interrupts<p>
The runtime for the Atmos uses routines marked as <tt/.INTERRUPTOR/ for
From d61feae7f8e61d02297c1b48ea93bf68bfdb31ef Mon Sep 17 00:00:00 2001
From: Greg King <gregdk@users.sf.net>
Date: Wed, 7 Jan 2015 10:51:48 -0500
Subject: [PATCH 4/8] Added a comment.
---
libsrc/atmos/tapehdr.s | 1 +
1 file changed, 1 insertion(+)
diff --git a/libsrc/atmos/tapehdr.s b/libsrc/atmos/tapehdr.s
index b8562eb02..b67f69d81 100644
--- a/libsrc/atmos/tapehdr.s
+++ b/libsrc/atmos/tapehdr.s
@@ -7,6 +7,7 @@
; to force this module to be included into the output file.
.export __TAPEHDR__:abs = 1
+ ; These symbols, also, come from the configuration file.
.import __BASHDR_LOAD__, __ZPSAVE_LOAD__, __AUTORUN__, __PROGFLAG__
From 22e06c41d1608ee1b4f79353b7f2b21b831de29c Mon Sep 17 00:00:00 2001
From: Greg King <gregdk@users.sf.net>
Date: Thu, 8 Jan 2015 03:51:20 -0500
Subject: [PATCH 5/8] Fixed a bug that had padded Atmos binaries with 25 bytes
too many.
---
cfg/atmos.cfg | 3 ++-
libsrc/atmos/crt0.s | 9 ++++++---
libsrc/atmos/tapehdr.s | 6 +++---
3 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/cfg/atmos.cfg b/cfg/atmos.cfg
index 691bd467d..5bb61bb26 100644
--- a/cfg/atmos.cfg
+++ b/cfg/atmos.cfg
@@ -23,7 +23,8 @@ SEGMENTS {
RODATA: load = RAM, type = ro;
INIT: load = RAM, type = ro, define = yes, optional = yes;
DATA: load = RAM, type = rw;
- ZPSAVE: load = RAM, type = rw, define = yes;
+ ZPSAVE1: load = RAM, type = rw, define = yes;
+ ZPSAVE2: load = RAM, type = bss;
BSS: load = RAM, type = bss, define = yes;
}
FEATURES {
diff --git a/libsrc/atmos/crt0.s b/libsrc/atmos/crt0.s
index 63961bfe8..ecbc00391 100644
--- a/libsrc/atmos/crt0.s
+++ b/libsrc/atmos/crt0.s
@@ -2,7 +2,7 @@
; Startup code for cc65 (Oric version)
;
; By Debrune J�r�me <jede@oric.org> and Ullrich von Bassewitz <uz@cc65.org>
-; 2014-11-09, Greg King
+; 2015-01-08, Greg King
;
.export _exit
@@ -31,7 +31,8 @@ L1: lda sp,x
jsr zerobss
-; Unprotect screen columns 0 and 1.
+; Currently, color isn't supported on the text screen.
+; Unprotect screen columns 0 and 1 (where each line's color codes would sit).
lda STATUS
sta stsave
@@ -81,7 +82,7 @@ L2: lda zpsave,x
; ------------------------------------------------------------------------
-.segment "ZPSAVE"
+.segment "ZPSAVE1"
zpsave:
@@ -91,6 +92,8 @@ zpsave:
.byte 0
+.segment "ZPSAVE2"
+
.res zpspace - 1
; ------------------------------------------------------------------------
diff --git a/libsrc/atmos/tapehdr.s b/libsrc/atmos/tapehdr.s
index b67f69d81..d90c908eb 100644
--- a/libsrc/atmos/tapehdr.s
+++ b/libsrc/atmos/tapehdr.s
@@ -1,6 +1,6 @@
;
; Based on code by Debrune J�r�me <jede@oric.org>
-; 2013-08-15, Greg King
+; 2015-01-08, Greg King
;
; The following symbol is used by the linker config. file
@@ -8,7 +8,7 @@
.export __TAPEHDR__:abs = 1
; These symbols, also, come from the configuration file.
- .import __BASHDR_LOAD__, __ZPSAVE_LOAD__, __AUTORUN__, __PROGFLAG__
+ .import __BASHDR_LOAD__, __ZPSAVE1_LOAD__, __AUTORUN__, __PROGFLAG__
; ------------------------------------------------------------------------
@@ -23,7 +23,7 @@
.byte $00 ; $2AF
.byte <__PROGFLAG__ ; $2AE Language flag ($00=BASIC, $80=machine code)
.byte <__AUTORUN__ ; $2AD Auto-run flag ($C7=run, $00=only load)
- .dbyt __ZPSAVE_LOAD__ ; $2AB Address of end of file
+ .dbyt __ZPSAVE1_LOAD__ ;$2AB Address of end of file
.dbyt __BASHDR_LOAD__ ; $2A9 Address of start of file
.byte $00 ; $2A8
From 43342366ed1bc365f9dd6918bd160b8e60dcd073 Mon Sep 17 00:00:00 2001
From: Greg King <gregdk@users.sf.net>
Date: Thu, 8 Jan 2015 17:07:28 -0500
Subject: [PATCH 6/8] Added comments that say why the ZPSAVE1 and ZPSAVE2
segments must be together.
---
cfg/atmos.cfg | 4 ++--
libsrc/atmos/crt0.s | 3 +++
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/cfg/atmos.cfg b/cfg/atmos.cfg
index 5bb61bb26..a1f935efa 100644
--- a/cfg/atmos.cfg
+++ b/cfg/atmos.cfg
@@ -23,8 +23,8 @@ SEGMENTS {
RODATA: load = RAM, type = ro;
INIT: load = RAM, type = ro, define = yes, optional = yes;
DATA: load = RAM, type = rw;
- ZPSAVE1: load = RAM, type = rw, define = yes;
- ZPSAVE2: load = RAM, type = bss;
+ ZPSAVE1: load = RAM, type = rw, define = yes; # ZPSAVE1, ZPSAVE2 must be together
+ ZPSAVE2: load = RAM, type = bss; # see "libsrc/atmos/crt0.s"
BSS: load = RAM, type = bss, define = yes;
}
FEATURES {
diff --git a/libsrc/atmos/crt0.s b/libsrc/atmos/crt0.s
index ecbc00391..61f40cc9a 100644
--- a/libsrc/atmos/crt0.s
+++ b/libsrc/atmos/crt0.s
@@ -92,6 +92,9 @@ zpsave:
.byte 0
+; The segments "ZPSAVE1" and "ZPSAVE2" always must be together.
+; They create a single object (the zpsave buffer).
+
.segment "ZPSAVE2"
.res zpspace - 1
From 2ef83bd66ceb7947a79c08e1cee213de03ec96cb Mon Sep 17 00:00:00 2001
From: Greg King <gregdk@users.sf.net>
Date: Fri, 9 Jan 2015 13:55:16 -0500
Subject: [PATCH 7/8] Mentioned, in the Atmos document, the extra byte at the
end of program binaries.
---
doc/atmos.sgml | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/doc/atmos.sgml b/doc/atmos.sgml
index 913e50ed7..68f7f9d65 100644
--- a/doc/atmos.sgml
+++ b/doc/atmos.sgml
@@ -7,7 +7,7 @@
<url url="mailto:uz@cc65.org" name="Ullrich von Bassewitz">,<newline>
<url url="mailto:polluks@sdf.lonestar.org" name="Stefan A. Haubenthal">,<newline>
<url url="mailto:greg.king5@verizon.net" name="Greg King">
-<date>2014-12-05
+<date>2015-01-09
<abstract>
An overview over the Atmos runtime system as it is implemented for the cc65 C
@@ -37,9 +37,11 @@ information.
The standard binary output format generated by the linker for the Atmos target
is a machine language program with a one-line BASIC stub that jumps to the
-machine-language part through <tt/CALL/. It has a 24-byte tape header.
-It means that a file can be loaded as a BASIC program, and started with RUN.
-The standard load address is $501.
+machine-language part through <tt/CALL/. It has one sacrificial byte attached
+to the end (a bug in the Oric ROM means that BASIC can put a variable on top
+of the last byte that was loaded). It has a 24-byte tape header. A file can
+be CLOADed as a BASIC program, and started by typing <tt/RUN/. The standard
+load address is $501.
From fccd2bf66a834bd8682720705a4b56bdfe9df001 Mon Sep 17 00:00:00 2001
From: Greg King <gregdk@users.sf.net>
Date: Fri, 9 Jan 2015 22:19:35 -0500
Subject: [PATCH 8/8] Added more info to a comment.
---
libsrc/atmos/crt0.s | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/libsrc/atmos/crt0.s b/libsrc/atmos/crt0.s
index 61f40cc9a..e789b28c2 100644
--- a/libsrc/atmos/crt0.s
+++ b/libsrc/atmos/crt0.s
@@ -2,7 +2,7 @@
; Startup code for cc65 (Oric version)
;
; By Debrune J�r�me <jede@oric.org> and Ullrich von Bassewitz <uz@cc65.org>
-; 2015-01-08, Greg King
+; 2015-01-09, Greg King
;
.export _exit
@@ -89,6 +89,7 @@ zpsave:
; This padding is needed by a bug in the ROM.
; (The CLOAD command starts BASIC's variables table on top of the last byte
; that was loaded [instead of at the next address].)
+; This is overlaid on a buffer, so that it doesn't use extra space in RAM.
.byte 0