From 1ead39db6ea680a769184cc97e3f27652d08cba7 Mon Sep 17 00:00:00 2001
From: Vince Weaver <vince@deater.net>
Date: Mon, 28 Aug 2023 21:45:35 -0400
Subject: [PATCH] fake_bios: detect language card

---
 graphics/hgr/fake_bios/Makefile    |  2 +-
 graphics/hgr/fake_bios/fake_bios.s | 44 ++++++++++++++++++++++++------
 graphics/hgr/fake_bios/lc_detect.s | 40 +++++++++++++++++++++++++++
 3 files changed, 77 insertions(+), 9 deletions(-)
 create mode 100644 graphics/hgr/fake_bios/lc_detect.s

diff --git a/graphics/hgr/fake_bios/Makefile b/graphics/hgr/fake_bios/Makefile
index d7be85a8..a4c32c78 100644
--- a/graphics/hgr/fake_bios/Makefile
+++ b/graphics/hgr/fake_bios/Makefile
@@ -26,7 +26,7 @@ FAKE_BIOS:	fake_bios.o
 fake_bios.o:	fake_bios.s \
 	hgr_clear_screen.s \
 	font_console_1x8.s fonts/a2_cga_thin.inc \
-	pt3_lib_detect_model.s \
+	pt3_lib_detect_model.s lc_detect.s \
 	zx02_optim.s graphics/a2_energy.hgr.zx02
 	ca65 -o fake_bios.o fake_bios.s -l fake_bios.lst
 
diff --git a/graphics/hgr/fake_bios/fake_bios.s b/graphics/hgr/fake_bios/fake_bios.s
index 6afe5a86..552eecea 100644
--- a/graphics/hgr/fake_bios/fake_bios.s
+++ b/graphics/hgr/fake_bios/fake_bios.s
@@ -18,9 +18,9 @@ bios_test:
 
 	jsr	build_tables
 
-	;===================
-	; Hardware Detect
-	;===================
+	;=======================
+	; Hardware Detect Model
+	;=======================
 
 	jsr	detect_appleii_model
 
@@ -52,6 +52,31 @@ not_iigs:
 	lda	APPLEII_MODEL
 	sta	model_patch_1+8	; patch to ' ' '+' 'e' 'c' or 'g'
 
+	;=======================
+	; Hardware Detect RAM
+	;=======================
+
+	lda	#48		; FIXME: detect less on earlier models?
+	sta	TOTAL_RAM
+
+	jsr	detect_language_card
+	bcs	ram_no_lc
+ram_yes_lc:
+	; carry clear here
+	lda	#16
+	adc	TOTAL_RAM
+	sta	TOTAL_RAM
+
+	; update text string
+	lda	#'1'
+	sta	lang_card_patch+34
+	lda	#'6'
+	sta	lang_card_patch+35
+
+
+ram_no_lc:
+
+
 
 	;===================
 	; Load graphics
@@ -91,7 +116,7 @@ not_iigs:
 	;=========================
 	; do fake memory count
 
-	lda	#128
+	lda	TOTAL_RAM
 	sta	MEMCOUNT
 memcount_loop:
 	lda	KEYPRESS				; 4
@@ -102,7 +127,7 @@ memcount_loop:
 
 	jsr	increment_memory
 	dec	MEMCOUNT
-	bpl	memcount_loop
+	bne	memcount_loop
 
 done_memcount:
 
@@ -238,9 +263,11 @@ bios_message_2:
 	.byte $1E,$1E,$1E,$1E,$1E,$1E,$1E,$1E
 	.byte $1E,$1E,$1E,$1E,$1E,$1E
 	.byte $1C, 13,0
-	.byte $1F," CPU Type: 65C02  ",$14," Base Memory: 48K  ",$1F,13,0 ; 16
-	.byte $1F," Co-Proc:   NONE  ",$14," Lang Card:   16K  ",$1F,13,0  ; 24
-	.byte $1F," Clock:  1.023MHz ",$14," AUX Memory:  64K  ",$1F,13,0  ; 32
+	.byte $1F," CPU Type:  6502  ",$14," Base Memory: 48K  ",$1F,13,0 ; 16
+lang_card_patch:  ; +34
+	.byte $1F," Co-Proc:   NONE  ",$14," Lang Card:    0K  ",$1F,13,0  ; 24
+aux_mem_patch:	; +34
+	.byte $1F," Clock:  1.023MHz ",$14," AUX Memory:   0K  ",$1F,13,0  ; 32
 
 	.byte $19 ; 40
 	.byte $1E,$1E,$1E,$1E,$1E,$1E,$1E,$1E
@@ -562,3 +589,4 @@ early_out:
 .include "hgr_clear_screen.s"
 
 .include "pt3_lib_detect_model.s"
+.include "lc_detect.s"
diff --git a/graphics/hgr/fake_bios/lc_detect.s b/graphics/hgr/fake_bios/lc_detect.s
new file mode 100644
index 00000000..3123a6ae
--- /dev/null
+++ b/graphics/hgr/fake_bios/lc_detect.s
@@ -0,0 +1,40 @@
+; Code from TotalReplay by 4am and qkumba
+
+;------------------------------------------------------------------------------
+; Has64K
+; Checks whether computer has functioning language card (64K)
+;
+; in:    none
+; out:   C clear if 64K detected
+;        C set if 64K not detected
+;        all other flags and registers clobbered
+;        ROM in memory (not LC RAM bank)
+;------------------------------------------------------------------------------
+
+detect_language_card:
+
+	; enable language card
+	; READ_RAM1_WRITE_RAM1
+
+	bit	$C08B
+	bit	$C08B
+
+	lda	#$AA			; test #1 for $D0 page
+	sta	$D000
+	eor	$D000
+	bne	no_lc
+	lsr	$D000			; test #2 for $D0 page
+	lda	#$55
+	eor	$D000
+	bne	no_lc
+	clc
+	bcc	done_detect
+
+no_lc:
+	sec
+
+done_detect:
+	; READ_ROM_NO_WRITE
+	bit	$C08A
+
+	rts