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Added Sym-1 extended memory sample program and documentation

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This commit is contained in:
Wayne Parham
2022-03-03 17:47:31 -06:00
parent 1cb18182ed
commit 81338a61c3
3 changed files with 106 additions and 5 deletions
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7
samples/sym1/Makefile
View File

@@ -32,7 +32,7 @@ else
endif
EXELIST_sym1 = \
symHello.bin symTiny.bin symDisplay.bin symIO.bin symNotepad.bin
symHello.bin symTiny.bin symDisplay.bin symIO.bin symNotepad.bin symExtendedMemory.bin
ifneq ($(EXELIST_$(SYS)),)
samples: $(EXELIST_$(SYS))
@@ -64,9 +64,14 @@ symIO.bin: symIO.c
symNotepad.bin: symNotepad.c
$(CL) -t sym1 -C sym1-32k.cfg -O -o symNotepad.bin symNotepad.c
symExtendedMemory.bin: symExtendedMemory.c
$(CL) -t sym1 -C sym1-32k.cfg -O -o symExtendedMemory.bin symExtendedMemory.c
clean:
@$(DEL) symHello.bin 2>$(NULLDEV)
@$(DEL) symTiny.bin 2>$(NULLDEV)
@$(DEL) symDisplay.bin 2>$(NULLDEV)
@$(DEL) symIO.bin 2>$(NULLDEV)
@$(DEL) symNotepad.bin 2>$(NULLDEV)
@$(DEL) symExtendedMemory.bin 2>$(NULLDEV)

95
samples/sym1/symExtendedMemory.c Normal file
View File

@@ -0,0 +1,95 @@
// --------------------------------------------------------------------------
// Sym-1 Extended Memory
//
// Wayne Parham
//
// wayne@parhamdata.com
// --------------------------------------------------------------------------
//
// Note: This program examines memory above the monitor ROM (8000-8FFF) to
// Determine what, if any, memory is available. It then adds whatever
// 4K segments it finds to the heap.
//
// Memory Segment Remark
// 0x9000 Usually available
// 0xA000 System I/O, always unavailable
// 0xB000 Used by RAE, but normally available
// 0xC000 Used by BASIC, normally unavailable
// 0xD000 Used by BASIC, normally unavailable
// 0xE000 Used by RAE, but normally available
// 0xF000 Normally available, but only to FF7F
//
// --------------------------------------------------------------------------
#include <sym1.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define SEGMENT 0x9000 // First 4K segment of extended memory
#define SEG_END 0x0FFF // Last location of segment
#define BLOCK_SIZE 0x1000 // Size of segment
#define TOP_END 0x0F7F // Last location of memory
#define TOP_SIZE 0x0F80 // Size of top segment
#define UNAVAILABLE 0xA000 // System I/O area
int main (void) {
int error = 0;
unsigned heap_size = 0x0000;
char* segment = (char*) SEGMENT;
printf ( "Analyzing memory.\n\n" );
heap_size = _heapmemavail();
printf ( "Main memory has %d bytes available.\n", heap_size );
while ( (int) segment < 0xEFFF ) { // Iterate through 4K memory blocks
if( (int) segment != UNAVAILABLE ) {
segment[0] = 0x00; // Check beginning of segment
if ( segment[0] != 0x00 )
error = 1;
segment[0] = 0xFF;
if ( segment[0] != 0xFF )
error = 1;
segment[SEG_END] = 0x00; // Check end of segment
if ( segment[SEG_END] != 0x00 )
error = 1;
segment[SEG_END] = 0xFF;
if ( segment[SEG_END] != 0xFF )
error = 1;
if ( ! error ) { // If memory found, add to the heap
printf ( "Memory found at location %p, ", segment );
_heapadd ( segment, BLOCK_SIZE );
heap_size = _heapmemavail();
printf( "so the system now has %u bytes available.\n", heap_size );
} else {
error = 0;
}
}
segment += 0x1000; // Increment to next segment
}
segment[0] = 0x00; // Check beginning of top memory segment
if ( segment[0] != 0x00 )
error = 1;
segment[0] = 0xFF;
if ( segment[0] != 0xFF )
error = 1;
segment[TOP_END] = 0x00; // Check end of usable memory
if ( segment[TOP_END] != 0x00 )
error = 1;
segment[TOP_END] = 0xFF;
if ( segment[TOP_END] != 0xFF )
error = 1;
if ( ! error ) { // If memory found, add to the heap
printf ( "Memory found at location %p, ", segment );
_heapadd ( segment, TOP_SIZE );
heap_size = _heapmemavail();
printf( "so the system now has %u bytes available.\n", heap_size );
}
puts ("\nEnjoy your day!\n");
return 0;
}