Updated ZX Spectrum port to use 64-character output.

This is accomplished via a tiny font, and a new output routine hooked
up to stream #4.

Author: skx

README.md

@@ -1,15 +1,11 @@
 # The Lighthouse of Doom
 
 This repository contain a simple text-based adventure game, implemented
-twice, once in portable C, and once in Z80 assembly language, available
-for both the CP/M operating system and the humble 48k ZX Spectrum.
+twice, once in portable C, and once in Z80 assembly language.
 
-My intention was to write a simple text-based adventure game to run under
-CP/M.  Starting large projects in Z80 assembly language from scratch
-is a bit of a daunting prospect, so I decided to code the game in C first,
-so that I could get the design right, and avoid getting stuck in too many
-low-level details initially.  Later I ported to the Spectrum, because
-it seemed like a fun challenge for myself!
+The Z80 version of the game will run under the CP/M operating system, and the humble 48k ZX Spectrum.
+
+My intention was to write a simple text-based adventure game to run under CP/M.  Starting large projects in Z80 assembly language from scratch is a bit of a daunting prospect, so I decided to code the game in C first, so that I could get the design right, and avoid getting stuck in too many low-level details initially.  Later I ported to the Spectrum, because it seemed like a fun challenge for myself!
 
 Quick links within this README file:
 
@@ -71,8 +67,7 @@ too much state to care about:
 
 ## Z80 Implementation
 
-The Z80 implementation is based upon the C-implementation, with a few
-small changes.
+The Z80 implementation is based upon the C-implementation, with a few small changes.
 
 The implementation uses a simple set of structures:
 

bios.z80

@@ -33,7 +33,11 @@ bios_init:
 
 IF SPECTRUM
    ld a,2
-   call 5633    ; CHAN_OPEN
+   call 5633  ; ROM_OPEN_CHANNEL
+   call c_chan
+   ld a,4
+   call 5633  ; ROM_OPEN_CHANNEL
+
 ENDIF
    ret
 ; }}
@@ -88,6 +92,23 @@ IF SPECTRUM
         ld a,2
         call 0x1601  ; ROM_OPEN_CHANNEL
         call 0x0DAF  ; ROM_CLS
+
+        ;
+        ; The code above will clear the screen, however we use a custom
+        ; printing routine which has its own notion of the X,Y / AT
+        ; coordinates to use.
+        ;
+        ; We explicitly reset those here, otherwise the screen will be clear,
+        ; but printing will start at whatever spot it finished the previous
+        ; time something was output.
+        ;
+        xor a
+        ld hl,atflg
+        ld (hl),a
+        ld hl, row
+        ld (hl),a
+        ld hl, col
+        ld (hl),a
         POP_ALL
         ret
 
@@ -182,8 +203,16 @@ continue_print:
         inc de
         jr length_check
 length_found:
+        PUSH_ALL
+        ld a,4
+        call 5633  ; ROM_OPEN_CHANNEL
+        POP_ALL
+
+        ; DE has the text to print
+        ; BC has the length
+        ; Call 0x203C to print
         pop de
-        call 0x203C
+        call 8252
 ELSE
         ld c, 0x09
         call 0x005

game.z80

@@ -365,6 +365,11 @@ no_handler:
 
 
 
+;********************************************************************
+; Include our custom printing routine
+;********************************************************************
+include "prn.z80"
+
 
 
 ;********************************************************************
@@ -2592,6 +2597,7 @@ include "bios.z80"
 
 
 
+
 ;********************************************************************
 ; Data / State Storage
 ;********************************************************************
@@ -2621,8 +2627,8 @@ SHIP_WARNING:
 call_911_msg:
 call_999_msg:
 call_police_msg:
-        db 0x0a, 0x0d, "Unfortunately Mayor Goodway's budget mishandling have resulted in a lack of", 0x0a, 0x0d
-        db "a functioning police force.", 0x0a, 0x0d
+        db 0x0a, 0x0d, "Unfortunately Mayor Goodway's budget mishandling have resulted", 0x0a, 0x0d
+        db " in a lack of a functioning police force.", 0x0a, 0x0d
         db 0x0a, 0x0d, "The best you can do is call a bunch of dogs, and their teenaged handler.", 0x0a, 0x0d, "$"
 call_unknown_msg:
         db 0x0a, 0x0d, "I'm sorry I don't know who that is.", 0x0a, 0x0d, "$"
@@ -2634,7 +2640,11 @@ call_ryder_msg:
         db 0x0a, 0x0d, 0x0a, 0x0d, "Sorry!", 0x0a, 0x0d, "$"
 call_skye_msg:
         db 0x0a, 0x0d, "Skye responds quickly, but over the sound of air roaring down the phone you", 0x0a, 0x0d
-        db "cannot hear what she's saying.  She must be a bit up in the air at the moment.", 0x0a, 0x0d, "$"
+        db "cannot hear what she's saying.", 0x0a, 0x0d
+        db "She must be a bit up in the air at the moment.", 0x0a, 0x0d, "$"
+call_steve_msg:
+        db 0x0a, 0x0d, "Steve doesn't publish his phone number.", 0x0a, 0x0d
+        db 0x0a, 0x0d, "But emails to steve@steve.fi would be most welcome.", "$"
 call_rubble_msg:
         db 0x0a, 0x0d, "Rubble doesn't answer your call."
         db 0x0a, 0x0d, "He's probably enjoying a nap.", 0x0a, 0x0d, "$"
@@ -2802,19 +2812,18 @@ THE:
 ON:
         db " ON "
 usage_message:
+        db 0x0a, 0x0d
+        db "        .n.         "
+IF SPECTRUM
+ELSE
+        db 27, "[1;4m"
+ENDIF
+        db "The lighthouse of doom"
 IF SPECTRUM
-        db "                                "
-        db "                                "
-        db "                                "
-        db "The lighthouse of Doom          "
-        db "                                "
-        db "            (c) 2022 Steve Kemp "
-        db "                                "
-        db "                                "
-        db " Press any key to start.        $"
 ELSE
+        db 27, "[1;0m"
+ENDIF
         db 0x0a, 0x0d
-        db "        .n.         ", 27, "[1;4mThe lighthouse of doom", 27, "[1;0m",  0x0a, 0x0d
         db "       /___\\ ", 0x0a, 0x0d
         db "       [|||]        ", 0x0a, 0x0d
         db "       [___]        ", 0x0a, 0x0d
@@ -2845,7 +2854,7 @@ include "version.z80"
         db "Any references to the Paw Patrol are entirely deliberate."
         db 0x0a, 0x0d, 0x0a, 0x0d
         db "Press any key to start.$"
-ENDIF
+
 
 play_again_msg:
         db 0x0a, 0x0d, "Play again? (y/n)$"
@@ -3148,6 +3157,8 @@ people_table:
              DEFW call_ryder_msg
         DEFB 4, 'SKYE'
              DEFW call_skye_msg
+        DEFB 5, 'STEVE'
+             DEFW call_steve_msg
         DEFB 6, 'RUBBLE'
              DEFW call_rubble_msg
         DEFB 2, 'ME'
@@ -3532,7 +3543,6 @@ TMP_BUFFER_LEN: EQU 50
 
 ; }}
 
-
 ;
 ; Our source code ends here.
 ;