Compressed ROM for EaZyZ80-512, Issue #500

Thanks and credit to Paul de Bak for providing the compression utility.

Co-Authored-By: PauldB <169483608+p42db@users.noreply.github.com>

Doc/ChangeLog.txt

@@ -33,6 +33,7 @@ Version 3.6
 - HJB: Added loader for MSX
 - HJB: Added IDE driver master media detect option
 - WBW: Add support for S100 Serial I/O DLP Serial connection
+- P?D: Generate compressed ROM for EaZyZ80 512
 
 Version 3.5.1
 -------------

Source/Clean.cmd

@@ -27,3 +27,4 @@ pushd ZRC && call Clean & popd
 pushd Z1RCC && call Clean & popd
 pushd ZZRCC && call Clean & popd
 pushd MSX && call Clean & popd
+pushd EZ512 && call Clean & popd

Source/EZ512/Build.cmd

@@ -3,9 +3,13 @@ setlocal
 
 set TOOLS=../../Tools
 
-set PATH=%TOOLS%\srecord;%PATH%
+set PATH=%TOOLS%\zxcc;%TOOLS%\srecord;%TOOLS%\compress;%PATH%
 
-for %%f in (..\..\Binary\RCZ80_ez512_*.rom) do call :build %%~nf
+set CPMDIR80=%TOOLS%/cpm/
+
+zxcc z80asm -decomp/HL
+
+for %%f in (..\..\Binary\RCZ80_ez512_*.upd) do call :build %%~nf
 
 goto :eof
 
@@ -23,4 +27,8 @@ move temp.dat ..\..\Binary\%1_hd1k_prefix.dat
 
 copy /b ..\..\Binary\%1_hd1k_prefix.dat + ..\..\Binary\hd1k_cpm22.img + ..\..\Binary\hd1k_zsdos.img + ..\..\Binary\hd1k_nzcom.img + ..\..\Binary\hd1k_cpm3.img + ..\..\Binary\hd1k_zpm3.img + ..\..\Binary\hd1k_ws4.img ..\..\Binary\%1_hd1k_combo.img || exit /b
 
+srec_cat ..\..\Binary\%1.upd -binary -exclude 0x13700 0x14A00 -fill 0xC9 0x13700 0x14A00 -o temp.upd -binary
+compress temp.upd
+srec_cat decomp.hex -intel temp.upd.cmp -binary -offset 3 -o ..\..\Binary\%1_64k.rom -binary
+
 goto :eof

Source/EZ512/Clean.cmd

@@ -1,3 +1,7 @@
 @echo off
 setlocal
 
+if exist *.upd del *.upd
+if exist *.cmp del *.cmp
+if exist *.hex del *.hex
+if exist *.lst del *.lst

Source/EZ512/Makefile

@@ -1,13 +1,15 @@
 DEST=../../Binary
+OTHERS=*.hex *.upd *.cmp
 
 HD1KIMGS = $(DEST)/hd1k_cpm22.img $(DEST)/hd1k_zsdos.img $(DEST)/hd1k_nzcom.img \
 	$(DEST)/hd1k_cpm3.img $(DEST)/hd1k_zpm3.img $(DEST)/hd1k_ws4.img
 
-ROMS := $(wildcard $(DEST)/RCZ80_ez512_*.rom)
-ROMS := $(patsubst $(DEST)/%.rom,%,$(ROMS))
+ROMS := $(wildcard $(DEST)/RCZ80_ez512_*.upd)
+ROMS := $(patsubst $(DEST)/%.upd,%,$(ROMS))
 
 OBJECTS := $(patsubst %,%_hd1k_prefix.dat,$(ROMS))
 OBJECTS += $(patsubst %,%_hd1k_combo.img,$(ROMS))
+OBJECTS += $(patsubst %,%_64k.rom,$(ROMS))
 
 TOOLS = ../../Tools
 
@@ -25,3 +27,8 @@ DIFFPATH = $(DIFFTO)/Binary
 
 %_hd1k_combo.img: %_hd1k_prefix.dat  $(HD1KIMGS)
 	cat $^ > $@
+
+%_64k.rom: $(DEST)/%.upd decomp.hex
+	srec_cat $< -binary -exclude 0x13700 0x14A00 -fill 0xC9 0x13700 0x14A00 -o temp.upd -binary
+	$(COMPRESS) temp.upd
+	srec_cat decomp.hex -intel temp.upd.cmp -binary -offset 3 -o $@ -binary

Source/EZ512/decomp.z80

@@ -0,0 +1,151 @@
+; 251003 decomp_rom_v1.1
+; Mark Pruden: Fix for omitted Bank 4
+;
+; 250208 decomp_rom v1.0
+; Paul de Bak: Renamed and used in RomWBW utility program 'compress_upd.c'
+; to compress *.upd binary files
+;
+;1/17/25
+;decompress RomWBW v1.0 - Original version by Bill Shen
+;Routine in ROM that decompress RomWBW data file into RAM and jump to it.
+;copy data file to RAM starting from bank 0, addr 0.
+;when encountered two consecutive bytes of same values, the tird byte following the consecutive values
+;  describe how many more identical bytes need to be added.
+;decompression ends when 3 banks (96KB) are expanded
+;compressed data is stored from address $3 to below $FF00
+;decompress program is located at $FF00
+
+;register usage
+;regC points to bankreg
+;regB is ROM source ($20)
+;regD is RAM destination bank
+;regE is previous value
+;regHL is destination pointer
+;regIX is source pointer
+;regIY points to byte count
+
+bankreg	equ 0ch		;PIO port C is 512K RAM bank register
+SIOAData	equ 8h		;location of SIO chan A data
+SIOACmd	equ 9h		;location of SIO ch A command/status reg
+SIOBData	equ 0ah		;location of SIO chan B data
+SIOBCmd	equ 0bh		;location of SIO ch B command/status reg
+PORTCData	equ 0ch		;PIA port C data
+PORTCCmd	equ 0dh		;PIA port C command
+
+	org 0
+	jp 0ff00h			;do program at top of memory
+dataRomWBW:
+;compressed RomWBW data appended here
+	org 0ff00h
+	ld a,09h			;write to KIO command reg first, enable PIA mux
+	out (0eh),a		;  SIO-CTC-PIO priority daisy chain
+
+	ld hl,0ff00h		;copy self into RAM
+	ld de,0ff00h
+	ld bc,100h
+	ldir
+
+	xor a			;PortC are all outputs. This will cause both RAM and ROM
+	out (PORTCCmd),a		; to be enabled until following OUT instruction, since RAM and
+				; ROM have same contents, this won't cause contention
+	ld a,00100010b		; ROM enable, RAM disable, bank$2, nRTSA, nRTSB enabled
+	out (PORTCData),a
+;register usage
+;regC points to bankreg
+;regB is ROM source ($20)
+;regD is RAM destination bank
+;regE is previous value
+;regHL is destination pointer
+;regIX is source pointer
+;regIY points to byte count
+	ld c,bankreg		;regC points to bank register IO address
+	ld e,0			;make sure regE is not the same as very first byte which is 0xC3
+	ld b,20h			;regB is ROM source
+	ld d,80h			;regD is RAM destination
+	ld hl,0			;destination starts from bank 0, address 0
+	ld ix,dataRomWBW		;regIX points to compressed RomWBW
+	ld iy,cSame		;regIY points to the count of same value
+start:
+	out (c),b			;read data from ROM
+;these two lines are executing program in ROM which has same program as RAM
+	ld a,(ix)			;read from source
+	out (c),d
+;running in RAM
+	ld (hl),a			;write to destination
+	cp e			;two consecutive same values?
+	jp z,decomp
+	ld e,a			;update the 'previous' value
+	inc ix			;next value in ROM
+	inc hl			;next destination value
+	ld a,h
+	cp 80h			;check for address greater than 32KB
+	jp z,nxtDbank
+	jp start
+nxtDbank:
+	ld hl,0
+	inc d			;next bank
+	ld a,d
+;;	cp 83h			;compare to bank 3
+	cp 84h			;MP compare to bank 4
+	jp z,decompDone
+	jp start
+decomp:
+	out (c),b			;read data from ROM
+;running in ROM
+	inc ix			;point to byte count of same value
+	ld a,(ix)			;get the count value
+	out (c),d			;switch to RAM bank
+;running in RAM
+	dec a			;reduce by 1 because one byte is already written
+	ld (iy),a			;store count to cSame pointed by regIY
+	jp z,DoDecomp2		;just two consecutive values
+DoDecomp:
+	inc hl			;next destination value
+	ld a,h
+	cp 80h
+	jp z,nxtDbank1
+DoDecomp1:
+	ld (hl),e			;write previous value (in regE) to destination
+	dec (iy)
+	jp nz,DoDecomp
+DoDecomp2:
+;done with block decompression, get ready to start over
+	out (c),b
+;running in ROM
+	inc ix			;point to next data in ROM
+	ld e,(ix)
+	dec e			;make sure previous value does not match, in case of large
+				; block (>256) of same values
+	out (c),d
+;running in RAM
+	inc hl
+	ld a,h
+	cp 80h			;check for address grater than 32KB
+	jp z,nxtDbank2
+	jp start
+nxtDbank1:
+	ld hl,0
+	inc d			;next bank
+	ld a,d
+	cp 83h			;compare to bank3
+	jp z,decompDone
+	out (c),d			;update bank before continuing
+	jp DoDecomp1
+nxtDbank2:
+	ld hl,0
+	inc d			;next bank
+	ld a,d
+	cp 83h			;compare to bank 3
+	jp z,decompDone
+	jp start
+decompDone:
+;decompression is done, reaching 96KB of data
+	ld a,80h			;ROM disable, RAM enable, bank$0, nRTSA, nRTSB enabled
+	out (c),a
+	jp 0			;execute RomWBW
+
+cSame:	db 0			;count of the same value
+
+	end
+
+

Source/ver.inc

@@ -2,7 +2,7 @@
 #DEFINE	RMN	6
 #DEFINE	RUP	0
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.6.0-dev.33"
+#DEFINE BIOSVER	"3.6.0-dev.34"
 #define rmj	RMJ
 #define rmn	RMN
 #define rup	RUP

Source/ver.lib

@@ -3,5 +3,5 @@ rmn	equ	6
 rup	equ	0
 rtp	equ	0
 biosver	macro
-	db	"3.6.0-dev.33"
+	db	"3.6.0-dev.34"
 	endm

Tools/Makefile.inc

@@ -45,6 +45,7 @@ OPENSPIN=$(BINDIR)/openspin
 CPMCP=$(BINDIR)/cpmcp
 CPMLS=$(BINDIR)/cpmls
 CPMCHATTR=$(BINDIR)/cpmchattr
+COMPRESS=$(BINDIR)/compress
 
 #
 # directory containing cpm binaries

Tools/unix/Makefile

@@ -13,7 +13,7 @@ ifeq ($(UNAME), Darwin)
 	SUFFIX=osx
 endif
 
-SUBDIRS = OpenSpin uz80as zxcc cpmtools bin2asm lzsa
+SUBDIRS = OpenSpin uz80as zxcc cpmtools bin2asm lzsa compress
 
 all:
 	@chmod +x casefn.sh

Tools/unix/compress/Makefile

@@ -0,0 +1,12 @@
+APP := compress
+OBJS := compress.o
+UNAME := $(shell uname)
+
+all: $(APP)
+	cp -p $(APP) ../../$(UNAME)
+
+$(APP): $(OBJS)
+	$(CC) $^ -o $@
+
+clean:
+	@rm -rf $(APP) $(OBJS)

Tools/unix/compress/compress.c

@@ -0,0 +1,150 @@
+/* =====================================================================
+ * compress v1.1 - 251012 Paul de Bak, with help from Le Chat AI
+ *
+ * =====================================================================
+ * This RomWBW utility program will attempt to compress any file using
+ * a straightforward RLE approach.
+ *
+ * The output file will have the name of the input file with ".cmp"
+ * appended.
+ *
+ * =====================================================================
+ * To compile in Linux (or Windows using MinGW):
+ *
+ *    gcc -o compress_upd(.exe)  compress_upd.c
+ *
+ * =====================================================================
+ * Usage:  compress(.exe)  <input file>
+ *
+ * If compression is successful, an ouput file is created with the name
+ * of the input file + ".cmp".
+ *
+ * =====================================================================
+ * Program exit codes
+ * 0: Success. An output file is created.
+ * 1: Incorrect usage or input file not found.
+ * 2: Unable to create output file.
+ *
+ * =====================================================================
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+//#include <string.h>
+//#include <libgen.h>  // For basename function
+
+#define VERSION "compress v1.1 - 251012 Paul de Bak & Le Chat AI"
+#define MAX_COUNT 0x100  // Maximum count is 256
+#define BUFFER_SIZE 65536
+
+size_t calculate_original_size(FILE *input) {
+    fseek(input, 0, SEEK_END);
+    return ftell(input);
+}
+
+size_t calculate_compressed_size(FILE *input) {
+    uint8_t buffer[BUFFER_SIZE];
+    size_t size, compressed_size = 0;
+    while ((size = fread(buffer, 1, BUFFER_SIZE, input)) > 0) {
+        size_t i = 0;
+        while (i < size) {
+            uint8_t byte = buffer[i];
+            size_t count = 1;
+            // Count the number of repetitions of the current byte
+            while (i + count < size && buffer[i + count] == byte && count < MAX_COUNT) {
+                count++;
+            }
+            if (count >= 2) {
+                compressed_size += 3;  // Two bytes + count
+            } else {
+                compressed_size += 1;  // Single byte
+            }
+            i += count;
+        }
+    }
+    return compressed_size;
+}
+
+int compress_file(FILE *input, FILE *output) {
+    uint8_t buffer[BUFFER_SIZE];
+    size_t size;
+    uint8_t repeat_count;
+    while ((size = fread(buffer, 1, BUFFER_SIZE, input)) > 0) {
+        size_t i = 0;
+        while (i < size) {
+            uint8_t byte = buffer[i];
+            size_t count = 1;
+            // Count the number of repetitions of the current byte
+            while (i + count < size && buffer[i + count] == byte && count < MAX_COUNT) {
+                count++;
+            }
+            if (count >= 2) {
+                fwrite(&byte, 1, 1, output);
+                fwrite(&byte, 1, 1, output);
+                repeat_count = count - 1;
+                fwrite(&repeat_count, 1, 1, output);
+            } else {
+                fwrite(&byte, 1, 1, output);
+            }
+            i += count;
+        }
+    }
+    return 1;
+}
+
+int main(int argc, char *argv[]) {
+    char *input_filename;
+    long free_bytes;
+    FILE *input;
+	size_t original_size;
+	size_t compressed_size;
+    char output_filename[256];
+    char *base_name;
+    char *dot;
+    FILE *output;
+
+    printf("\n%s\n\n", VERSION);
+
+    if (argc != 2) {
+        printf("Usage: %s  <input file>\n", argv[0]);
+        printf("Example: %s  RCZ80_ez512_std.upd\n", argv[0]);
+        return 1; // Error: Incorrect usage
+    }
+
+    input_filename = argv[1];
+	input = fopen(input_filename, "rb");
+    if (!input) {
+        fprintf(stderr, "Error: Input file '%s' not found\n", input_filename);
+        return 1; // Error: Input file not found
+    }
+	
+	// Calculate the original file size
+    original_size = calculate_original_size(input);
+    rewind(input);
+
+    // Calculate the compressed size first
+    compressed_size = calculate_compressed_size(input);
+    rewind(input);
+
+    // Construct the output filename
+	snprintf(output_filename, sizeof(output_filename), "%s.cmp", input_filename);
+	
+	printf("Compressing %s to %s...\n", input_filename, output_filename);
+
+    output = fopen(output_filename, "wb");
+    if (!output) {
+        fprintf(stderr, "Error: Unable to create output file '%s'\n", output_filename);
+        fclose(input);
+        return 2; // Error: Unable to create output file
+    }
+
+    compress_file(input, output);
+
+    fclose(input);
+    fclose(output);
+
+	printf("Compressed from %lu bytes to %lu bytes (%lu%% reduction)\n", original_size, compressed_size,  (((original_size - compressed_size) * 100) / original_size));
+	
+    return 0; // Success
+}