ti84: working!

Not yet tried on real hardware, but we should be getting pretty
close...

blk/569

@@ -4,7 +4,7 @@
         DROP
         1+ DUP 7 = IF DROP 0 THEN ( inc gid )
         1 OVER LSHIFT 0xff -^ ( group dmask ) _get
-    DUP 0xff = NOT UNTIL
+    DUP 0xff = NOT UNTIL _wait
     ( gid dmask )
     0xff XOR ( dpos ) 0 ( dindex )
     BEGIN 1+ 2DUP RSHIFT NOT UNTIL 1-

blk/570

@@ -8,5 +8,7 @@
         SWAP 0x81 = _2nd!
         _gti + C@
     DUP 0 0x80 >< UNTIL ( loop if not in range )
-    _wait ;
+    ( lowercase? )
+    _2nd@ IF DUP 'A' 'Z' =><= IF 0x20 OR THEN THEN
+;
 : KBD$ 0 [ KBD_MEM LITN ] C! ;

recipes/ti84/README.md

@@ -8,11 +8,24 @@ screen. With a tiny font, the best we can get is a 24x10 console.
 
 There is, however, a built-in USB controller that might prove very handy.
 
-[Further reading](../../doc/ti8x.md)
+I haven't opened one up yet, but apparently, they have limited scavenging value
+because its z80 CPU is packaged in a TI-specific chip. Due to its sturdy design,
+and its ample RAM and flash, we could imagine it becoming a valuable piece of
+equipment if found intact.
+
+The best pre-collapse ressource about it is
+[WikiTI](http://wikiti.brandonw.net/index.php).
+
+As it is now, with its tiny screen and cumbersome keyboard, Collapse OS is
+not really usable on the TI-84+. One could imagine a scenario where one has a
+terminal and uses the TI-84+ through the link for its large amount of flash and
+RAM. But using it standalone? Nah, not even post-collapse.
+
+Therefore, this recipe is more of a "look, I run!" demo.
 
 ## Recipe
 
-This recipe gets the Collapse OS BASIC shell to run on the TI-84+, using its LCD
+This recipe gets the Collapse OS interpreter to run on the TI-84+, using its LCD
 screen as output and its builtin keyboard as input.
 
 ## Gathering parts
@@ -25,7 +38,7 @@ screen as output and its builtin keyboard as input.
 
 ## Build the ROM
 
-Running `make` will result in `os.rom` being created.
+Running `make` will result in `stage1.rom` being created.
 
 ## Emulate
 
@@ -38,6 +51,30 @@ Collapse OS prompt will appear. See `emul/hw/ti/README.md` for details.
 
 ## Upload to the calculator
 
+### Background notes
+
+Getting software to run on it is a bit tricky because it needs to be signed
+with TI-issued private keys. Those keys have long been found and are included
+in `keys/`. With the help of the
+[mktiupgrade](https://github.com/KnightOS/mktiupgrade), an upgrade file can be
+prepared and then sent through the USB port with the help of
+[tilp](http://lpg.ticalc.org/prj_tilp/).
+
+That, however, requires a modern computing environment. As of now, there is no
+way of installing Collapse OS on a TI-8X+ calculator from another Collapse OS
+system.
+
+Because it is not on the roadmap to implement complex cryptography in Collapse
+OS, the plan is to build a series of pre-signed bootloader images. The
+bootloader would then receive data through either the Link jack or the USB port
+and write that to flash (I haven't verified that yet, but I hope that data
+written to flash this way isn't verified cryptographically by the calculator).
+
+As modern computing fades away, those pre-signed binaries would become opaque,
+but at least, would allow bootstrapping from post-modern computers.
+
+### Instructions
+
 **WARNING: the instructions below will wipe all the contents of your calculator,
 including TI-OS.**
 

recipes/ti84/glue.asm

@@ -1,116 +0,0 @@
-.equ	RAMSTART	0x8000
-.equ	RAMEND		0xbfff
-.equ	PORT_INT_MASK	0x03
-.equ	INT_MASK_ON	0x00
-.equ	PORT_INT_TRIG	0x04
-.equ	INT_TRIG_ON	0x00
-.equ	PORT_BANKB	0x07
-
-	jp	boot
-
-.fill 0x18-$
-	jp	boot		; reboot
-
-.fill 0x38-$
-	jp	handleInterrupt
-
-.fill 0x53-$
-	jp boot
-; 0x0056
-.db 0xFF, 0xA5, 0xFF
-
-.fill 0x64-$
-
-.inc "err.h"
-.inc "ascii.h"
-.inc "core.asm"
-.inc "str.asm"
-.equ	FNT_WIDTH	3
-.equ	FNT_HEIGHT	5
-.inc "fnt/mgm.asm"
-.equ	LCD_RAMSTART	RAMSTART
-.inc "ti/lcd.asm"
-.equ	KBD_RAMSTART	LCD_RAMEND
-.inc "ti/kbd.asm"
-.equ	STDIO_RAMSTART	KBD_RAMEND
-.equ	STDIO_GETC	kbdGetC
-.equ	STDIO_PUTC	lcdPutC
-.inc "stdio.asm"
-
-; *** BASIC ***
-
-; RAM space used in different routines for short term processing.
-.equ	SCRATCHPAD_SIZE	STDIO_BUFSIZE
-.equ	SCRATCHPAD	STDIO_RAMEND
-.inc "lib/util.asm"
-.inc "lib/ari.asm"
-.inc "lib/parse.asm"
-.inc "lib/fmt.asm"
-.equ	EXPR_PARSE	parseLiteralOrVar
-.inc "lib/expr.asm"
-.inc "basic/util.asm"
-.inc "basic/parse.asm"
-.inc "basic/tok.asm"
-.equ	VAR_RAMSTART	SCRATCHPAD+SCRATCHPAD_SIZE
-.inc "basic/var.asm"
-.equ	BUF_RAMSTART	VAR_RAMEND
-.inc "basic/buf.asm"
-.equ	BAS_RAMSTART	BUF_RAMEND
-.inc "basic/main.asm"
-
-.out BAS_RAMEND
-boot:
-	di
-	ld	sp, RAMEND
-	im	1
-
-	; enable ON key interrupt
-	in	a, (PORT_INT_MASK)
-	set	INT_MASK_ON, a
-	out	(PORT_INT_MASK), a
-	ld	a, 0x80
-	out	(PORT_BANKB), a
-
-	ei
-
-	call	lcdOff
-
-	; sleep until we press ON
-	halt
-
-main:
-	; Fun fact: if I place this line just above basStart like I would
-	; normally do, my TI-84+ refuses to validate the binary. But placed
-	; here, validation works fine.
-	call	basInit
-	call	kbdInit
-	call	lcdInit
-	xor	a
-	call	lcdSetCol
-	jp	basStart
-
-handleInterrupt:
-	di
-	push	af
-
-	; did we push the ON button?
-	in	a, (PORT_INT_TRIG)
-	bit	INT_TRIG_ON, a
-	jp	z, .done		; no? we're done
-
-	; yes? acknowledge and boot
-	in	a, (PORT_INT_MASK)
-	res	INT_MASK_ON, a		; acknowledge interrupt
-	out	(PORT_INT_MASK), a
-
-	pop	af
-	ei
-	jp	main
-
-.done:
-	pop	af
-	ei
-	reti
-
-FNT_DATA:
-.bin "fnt/3x5.bin"

recipes/ti84/user.h

@@ -1,2 +0,0 @@
-; RAMSTART + kernel usage + safety buffer
-.equ    USER_RAMSTART   0x8040

recipes/ti84/xcomp.fs

@@ -4,6 +4,7 @@ RAMSTART 0x70 + CONSTANT LCD_MEM
 RAMSTART 0x72 + CONSTANT KBD_MEM
 0x01 CONSTANT KBD_PORT
 212 LOAD  ( z80 assembler )
+: ZFILL, ( u ) 0 DO 0 A, LOOP ;
 262 LOAD  ( xcomp )
 522 LOAD  ( font compiler )
 : CODE XCODE ;
@@ -12,8 +13,55 @@ RAMSTART 0x72 + CONSTANT KBD_MEM
 : CREATE XCREATE ; ( for KBD tbls )
 : : [ ' X: , ] ;
 
+( TI-84+ requires specific code at specific offsets which
+  come in conflict with Collapse OS' stable ABI. We thus
+  offset the binary by 0x100, which is our minimum possible
+  increment and fill the TI stuff with the code below. )
+
+0x5a JPnn, 0x15 ZFILL, ( 0x18 )
+0x5a JPnn, ( reboot ) 0x1d ZFILL, ( 0x38 )
+( handleInterrupt )
+DI,
+AF PUSHqq,
+    ( did we push the ON button? )
+    0x04 ( PORT_INT_TRIG ) INAn,
+    0 ( INT_TRIG_ON ) A BITbr,
+    IFNZ,
+        ( yes? acknowledge and boot )
+        0x03 ( PORT_INT_MASK ) INAn,
+        0x00 ( INT_MASK_ON ) A RESbr, ( ack interrupt )
+        0x03 ( PORT_INT_MASK ) OUTnA,
+        AF POPqq,
+        EI,
+        0x100 JPnn,
+    THEN,
+AF POPqq,
+EI,
+RETI,
+
+0x03 ZFILL, ( 0x53 )
+0x5a JPnn, ( 0x56 ) 0xff A, 0xa5 A, 0xff A, ( 0x5a )
+( boot )
+DI,
+    (im1)
+    ( enable the ON key interrupt )
+    0x03 ( PORT_INT_MASK ) INAn,
+    0x00 ( INT_MASK_ON ) A SETbr,
+    0x03 ( PORT_INT_MASK ) OUTnA,
+    A 0x80 LDrn,
+    0x07 ( PORT_BANKB ) OUTnA,
+EI,
+( LCD off )
+A 0x02 ( LCD_CMD_DISABLE ) LDrn,
+0x10 ( LCD_PORT_CMD ) OUTnA,
+HALT,
+
+0x95 ZFILL, ( 0x100 )
+( All set, carry on! )
+
 CURRENT @ XCURRENT !
 
+0x100 BIN( !
 282 LOAD  ( boot.z80 )
 393 LOAD  ( icore low )
 555 557 LOADR ( LCD low )
@@ -27,5 +75,5 @@ PC ORG @ 8 + !
 558 560 XPACKR ( LCD high )
 438 451 XPACKR ( print fmt readln )
 ," : _ LCD$ KBD$ (ok) RDLN$ ; _ "
-ORG @ 256 /MOD 2 PC! 2 PC!
+ORG @ 0x100 - 256 /MOD 2 PC! 2 PC!
 H@ 256 /MOD 2 PC! 2 PC!