trs80: Add support for two consoles (shift-F1 and shift-F2)

Useful for debugging work and testing interactions.

The TRS80 cannot as far as I understand move the physical video base, so
we exchange the memory banks and do some additional pointer flipping and
the like to get it to work.

Cursor handling is still not quite right and needs debugging.

diff --git a/Kernel/platform-trs80/config.h b/Kernel/platform-trs80/config.h
index 01d60d2..0d1120d 100644 (file)
--- a/Kernel/platform-trs80/config.h
+++ b/Kernel/platform-trs80/config.h
@@ -15,6 +15,7 @@
 #define CONFIG_VT
 /* Simple character addressed device */
 #define CONFIG_VT_SIMPLE
+#define CONFIG_VT_MULTI
 /* Banked memory set up */
 #define CONFIG_BANK_FIXED
 #define MAX_MAPS       2
@@ -23,7 +24,7 @@
 #define CONFIG_BANKS   2       /* 2 x 32K */
 
 /* Vt definitions */
-#define VT_BASE                ((uint8_t *)0xF800)
+#define VT_BASE                vtbase[curtty]
 #define VT_WIDTH       80
 #define VT_HEIGHT      24
 #define VT_RIGHT       79

diff --git a/Kernel/platform-trs80/devtty.c b/Kernel/platform-trs80/devtty.c
index 304406b..338d736 100644 (file)
--- a/Kernel/platform-trs80/devtty.c
+++ b/Kernel/platform-trs80/devtty.c
@@ -9,6 +9,14 @@
 
 char tbuf1[TTYSIZ];
 char tbuf2[TTYSIZ];
+char tbuf3[TTYSIZ];
+
+uint8_t curtty;                /* output side */
+uint8_t inputtty;      /* input side */
+static struct vt_switch ttysave[2];
+static uint8_t vtbackbuf[VT_WIDTH * VT_HEIGHT];
+
+uint8_t *vtbase[2] = { 0xF800, vtbackbuf };
 
 __sfr __at 0xE8 tr1865_ctrl;
 __sfr __at 0xE9 tr1865_baud;
@@ -18,7 +26,8 @@ __sfr __at 0xEB tr1865_rxtx;
 struct  s_queue  ttyinq[NUM_DEV_TTY+1] = {       /* ttyinq[0] is never used */
     {   NULL,    NULL,    NULL,    0,        0,       0    },
     {   tbuf1,   tbuf1,   tbuf1,   TTYSIZ,   0,   TTYSIZ/2 },
-    {   tbuf2,   tbuf2,   tbuf2,   TTYSIZ,   0,   TTYSIZ/2 }
+    {   tbuf2,   tbuf2,   tbuf2,   TTYSIZ,   0,   TTYSIZ/2 },
+    {   tbuf3,   tbuf3,   tbuf3,   TTYSIZ,   0,   TTYSIZ/2 }
 };
 
 /* Write to system console */
@@ -32,18 +41,70 @@ void kputchar(char c)
 ttyready_t tty_writeready(uint8_t minor)
 {
     uint8_t reg;
-    if (minor == 1)
+    if (minor != 3)
         return TTY_READY_NOW;
     reg = tr1865_status;
     return (reg & 0x40) ? TTY_READY_NOW : TTY_READY_SOON;
 }
 
+void vtbuf_init(void)
+{
+    memset(vtbackbuf, ' ', VT_WIDTH * VT_HEIGHT);
+}
+void vtexchange(void)
+{
+        /* Swap the pointers over: TRS80 video we switch by copying not
+           flipping hardware pointers */
+        uint8_t *v = vtbase[0];
+        vtbase[0] = vtbase[1];
+        vtbase[1] = v;
+        /* The cursor x/y for current tty are stale in the save area
+           so save them */
+        vt_save(&ttysave[curtty]);
+
+        /* Before we flip the memory */
+        cursor_off();
+
+        /* Swap the buffers over */
+        __asm
+                ld hl, #0xf800
+                ld de, #_vtbackbuf
+                ld bc, #VT_WIDTH*VT_HEIGHT
+        exchit:
+                push bc
+                ld a, (de)     ; Could be optimised but its only 2K
+                ld c, (hl)     ; Probably worth doing eventuallly
+                ex de, hl
+                ld (hl), c
+                ld (de), a
+                inc hl
+                inc de
+                pop bc
+                dec bc
+                ld a, b
+                or c
+                jr nz, exchit
+                ret
+        __endasm;
+        /* Cursor back */
+        cursor_on(ttysave[inputtty].cursory, ttysave[inputtty].cursorx);
+}
+
 void tty_putc(uint8_t minor, unsigned char c)
 {
-    if (minor == 1)
-        vtoutput(&c, 1);
-    if (minor == 2)
+    irqflags_t irq;
+    if (minor == 3)
         tr1865_rxtx = c;
+    else {
+        irq = di();
+        if (curtty != minor -1) {
+            vt_save(&ttysave[curtty]);
+            curtty = minor - 1;
+            vt_load(&ttysave[curtty]);
+       }
+       vtoutput(&c, 1);
+       irqrestore(irq);
+   }
 }
 
 void tty_interrupt(void)
@@ -51,7 +112,7 @@ void tty_interrupt(void)
     uint8_t reg = tr1865_status;
     if (reg & 0x80) {
         reg = tr1865_rxtx;
-        tty_inproc(2, reg);
+        tty_inproc(3, reg);
     }
 }
 
@@ -68,7 +129,7 @@ void tty_setup(uint8_t minor)
 {
     uint8_t baud;
     uint8_t ctrl;
-    if (minor == 1)
+    if (minor != 3)
         return;
     baud = ttydata[2].termios.c_cflag & CBAUD;
     if (baud > B19200) {
@@ -90,14 +151,14 @@ void tty_setup(uint8_t minor)
 
 int trstty_close(uint8_t minor)
 {
-    if (minor == 2 &&ttydata[2].users == 0)
+    if (minor == 3 &&ttydata[2].users == 0)
         tr1865_ctrl = 0;       /* Drop carrier */
     return tty_close(minor);
 }
 
 int tty_carrier(uint8_t minor)
 {
-    if (minor == 1)
+    if (minor != 3)
         return 1;
     if (tr1865_ctrl & 0x80)
         return 1;
@@ -185,9 +246,17 @@ static void keydecode(void)
                return;
        }
 
-       if (keymap[7] & 3)      /* shift */
+       if (keymap[7] & 3) {    /* shift */
                c = shiftkeyboard[keybyte][keybit];
-       else
+               /* VT switcher */
+               if (c == KEY_F1 || c == KEY_F2) {
+                        if (inputtty != c - KEY_F1) {
+                                inputtty = c - KEY_F1;
+                                vtexchange();  /* Exchange the video and backing buffer */
+                        }
+                        return;
+                }
+        } else
                c = keyboard[keybyte][keybit];
 
         /* The keyboard lacks some rather important symbols so remap them
@@ -218,7 +287,7 @@ static void keydecode(void)
        else if (capslock && c >= 'a' && c <= 'z')
                c -= 'a' - 'A';
        if (c)
-               vt_inproc(1, c);
+               vt_inproc(inputtty+1, c);
 }
 
 void kbd_interrupt(void)

diff --git a/Kernel/platform-trs80/devtty.h b/Kernel/platform-trs80/devtty.h
index b816736..12714e4 100644 (file)
--- a/Kernel/platform-trs80/devtty.h
+++ b/Kernel/platform-trs80/devtty.h
@@ -4,10 +4,14 @@
 extern void tty_interrupt(void);
 extern void kbd_interrupt(void);
 extern int trstty_close(uint8_t minor);
+extern void vtbuf_init(void);
 
 #define KEY_ROWS       8
 #define KEY_COLS       8
 extern uint8_t keymap[8];
 extern uint8_t keyboard[8][8];
 extern uint8_t shiftkeyboard[8][8];
+
+extern uint8_t *vtbase[2];
+extern uint8_t curtty;
 #endif