First program to return to polmon

Makefile

@@ -6,8 +6,8 @@ dev-image = 5150-dev
 crc16.s: crc16.c
 	ia16-elf-gcc -S -Os -o crc16.s crc16.c
 
-crc16.bin: crc16.s crt0.c
+crc16.bin: crc16.s
-	ia16-elf-gcc -o crc16.bin -Os -nostdlib crc16.s crt0.c
+	ia16-elf-gcc -o crc16.bin -Os -nostdlib crc16.s
 
 CC = ia16-elf-gcc
 CXX = ia16-elf-gcc
@@ -31,11 +31,13 @@ fat12boot.elf: LDFLAGS += -T bootsect.ld
 
 fat12boot.bin: fat12boot.elf
 
+stdlib.o: CFLAGS := $(filter-out -flto, $(CFLAGS))
+
 polmon.elf: LDFLAGS += -T flat1000.ld
 polmon.elf: polmon.o stdlib.o
 
 polio.elf: LDFLAGS += -T flat0600.ld
-polio.elf: polio.s fat12.o
+polio.elf: polio-main.o polio.s fat12.o paracomm.o stdlib.o
 
 wozmon.o: polmon.cc
 wozmon.o: CPPFLAGS = -DWOZMON=1
@@ -51,12 +53,19 @@ wozmon.bin: wozmon.elf
 paracli.elf: LDFLAGS += -T doscom.ld
 paracli.elf: paracli.s paracomm.o
 
-polos.img: fat12boot.bin polmon.com polio.com paracli.com
+dos-programs = mushroom.elf hello.elf
+$(dos-programs): LDFLAGS += -T doscom.ld
+
+mushroom.elf: mushroom.s
+hello.elf: hello.o stdlib.o crt0.s
+
+polos.img: fat12boot.bin polmon.com polio.com mushroom.com hello.com
 	dd if=/dev/zero of=$@ bs=512 count=720
 	mformat -i $@ -t 40 -h 2 -s 9
 	mcopy -i $@ polio.com ::/
 	mcopy -i $@ polmon.com ::/
-	mcopy -i $@ paracli.com ::/
+	mcopy -i $@ mushroom.com ::/
+	mcopy -i $@ hello.com ::/
 	dd if=fat12boot.bin of=$@ conv=notrunc
 
 .PHONY: clean

arduino/kbd/kbd.ino

@@ -14,13 +14,9 @@ void setup() {
 
     pc = ParaComms{
             .mosi_cb =
-                    [](uint8_t *data, uint8_t len) {
+                    [](uint8_t* data, uint8_t len) {
                         for (int i = 0; i < len; i++) {
                             Serial.printf("%c", data[i]);
-                            pc.SendByte(data[i]); // echo
-                            if (data[i] == '\r') {
-                                pc.SendByte('\n');
-                            }
                         }
                     },
     };
@@ -41,7 +37,7 @@ void loop() {
     }
     led_counter += 1;
 
-    checkKbdReset();
+    // checkKbdReset();
 
     uint8_t mosib;
     if (strobeOccurred(mosib)) {
@@ -52,6 +48,9 @@ void loop() {
 
     if (Serial.available() > 0) {
         int c = Serial.read();
+#if 1
+        pc.SendByte(c);
+#else
         if (c == 2) {
             mode = 0;
         } else if (c == 3) {
@@ -63,5 +62,6 @@ void loop() {
                 pc.SendByte(c);
             }
         }
+#endif
     }
 }

bootsect.ld

@@ -14,7 +14,7 @@ SECTIONS {
         * (.bss)
     }
 
-    .data : {
+    .data (NOLOAD) : {
         *(.data)
     }
 

crc16.s

@@ -3,6 +3,11 @@
 	.att_syntax prefix
 #NO_APP
 #APP
+    .section .text.init
+    .global _start
+_start:
+
+    .section .text.main
 	.global main      
 main:             
   push %bp        

crt0.c

@@ -1,25 +0,0 @@
-#include <stdint.h>
-#include <string.h>
-
-int main();
-
-asm(".section .init     \n"
-    ".global _start     \n"
-    "_start:            \n\t"
-    "mov %cs, %ax       \n\t"
-    "mov %ax, %ds       \n\t"
-    "mov %ax, %es       \n\t"
-    "cli                \n\t"
-    "mov %ax, %ss       \n\t"
-    "mov $0x1000, %ax   \n\t"
-    "mov %ax, %sp       \n\t"
-    "sti                \n\t"
-    "jmp main");
-
-void* memset(void* ptr, int val, size_t len) {
-    uint8_t* p = ptr;
-    while (len--) {
-        *p++ = val;
-    }
-    return ptr;
-}

crt0.s

@@ -0,0 +1,8 @@
+    .arch i8086,jumps
+    .code16
+    .intel_syntax noprefix
+
+    .section .init
+    .global _start
+_start:
+    jmp main

doscom.ld

@@ -14,7 +14,7 @@ SECTIONS {
         * (.bss)
     }
 
-    .data : {
+    .data (NOLOAD) : {
         *(.data)
     }
 }

flat0600.ld

@@ -14,7 +14,7 @@ SECTIONS {
         * (.bss)
     }
 
-    .data : {
+    .data (NOLOAD) : {
         *(.data)
     }
 }

flat1000.ld

@@ -14,7 +14,7 @@ SECTIONS {
         * (.bss)
     }
 
-    .data : {
+    .data (NOLOAD) : {
         *(.data)
     }
 }

ftp.asm

@@ -0,0 +1,48 @@
+CPU 8086
+
+chunksize equ 0x20
+devicedelay equ 0x08
+
+_start:
+    push bp
+    mov bp, sp
+    sub sp, 8
+    mov [bp-2], word chunksize ; recv size
+    mov [bp-4], word 0xf000 ; recv addr
+    mov [bp-6], word 0x0001 ; send size
+    mov [bp-8], word 0x7000 ; send addr
+    mov bx, [bp-8]
+    mov [bx], byte 0x42
+l0:
+    cmp word [bp-4], 0xf600
+    jb l1
+l2:
+    mov sp, bp
+    pop bp
+    ret
+l1:
+    mov ah, 0x07
+    int 0x80
+    test al, al
+    jnz l1
+    push word [bp-2]
+    push word [bp-4]
+    mov ah, 0x05
+    int 0x80
+    test al, al
+    jz l2
+    mov ah, 0
+    add [bp-4], ax
+    push word [bp-6]
+    push word [bp-8]
+    mov ah, 0x06
+    int 0x80
+    add sp, 8
+    mov cx, devicedelay
+l3: 
+    mov ah, 0x07
+    push cx
+    int 0x80
+    pop cx
+    loop l3             ; give the device some time to answer
+    jmp l0

hello.c

@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+int main() {
+    puts("Hello, world!\r\n");
+}

mrbridge.py

@@ -0,0 +1,55 @@
+import argparse
+import serial
+import threading
+import time
+import websocket
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(description="Bridge a serial port to a websocket")
+    parser.add_argument("port", help="path to the serial port")
+    parser.add_argument("--baudrate", default=115200)
+    parser.add_argument("--escape", action='store_true')
+    parser.add_argument("ws", help="URL of the websocket")
+    return parser.parse_args()
+
+
+def device_thread(device, ws):
+    while True:
+        line = device.readline()
+        ws.send(line)
+
+
+def slowwrite(device, data):
+    for b in data:
+        device.write([b])
+        time.sleep(0.01)
+
+
+def ws_thread(device, ws):
+    while True:
+        data = ws.recv();
+        slowwrite(device, data.replace(b'\n', b'\r\n'))
+
+
+def main():
+    args = parse_args()
+    device = serial.Serial(args.port, baudrate=args.baudrate)
+    ws = websocket.create_connection(args.ws)
+
+    wst = threading.Thread(target=ws_thread, args=(device, ws), daemon=True)
+    wst.start()
+
+    if args.escape:
+        device.write([0x03])
+    try:
+        device_thread(device, ws)
+    except KeyboardInterrupt:
+        pass
+    finally:
+        if args.escape:
+            device.write([0x02])
+
+
+if __name__ == "__main__":
+    main()

mushroom.s

@@ -0,0 +1,261 @@
+    .arch i8086,jumps
+    .code16
+    .intel_syntax noprefix
+
+    .section .init
+    .global _start
+_start:
+    mov ax, cs
+    mov ds, ax
+    mov es, ax
+    cli
+    mov ss, ax
+    mov sp, 0x100
+    sti
+    jmp main
+
+    .section .bss
+kBufSize = 77
+kDividerRow = 23
+kRecvBufSize = 128
+
+curpos: .word 0
+inputsize: .byte 0
+escaped: .byte 0
+inputbuf: .zero kBufSize
+recvbuf: .zero kRecvBufSize
+
+    # XXX: funky call
+    # inputs:
+    #   si: string offset
+    #   cl: string length
+    # clobbers: ax, bh, dx
+    .section .text.printn
+printn:
+    push bx
+    push bp
+    mov bh, 0
+1:
+    test cl, cl
+    jz 0f
+    mov al, [si]
+    cmpb escaped, 0
+    je 3f
+    cmp al, 'm'
+    jne 5f
+    movb escaped, 0
+    jmp 5f
+3:
+    cmp al, 0x1b        # ESC
+    jne 4f
+    movb escaped, 1
+    jmp 5f
+4:
+    mov ah, 0x0e        # write tty
+    int 0x10
+    push cx
+    mov ah, 0x03        # get cursor
+    int 0x10
+    cmp dh, kDividerRow
+    jb 2f
+    push dx
+    mov ah, 0x08        # read color
+    int 0x10
+    mov bh, ah
+    xor cx, cx
+    mov dx, 0x164f
+    mov ax, 0x0601      # scroll up, 1 line
+    int 0x10
+    pop dx
+    dec dh
+    mov bh, 0
+    mov ah, 0x02        # set cursor
+    int 0x10
+2:
+    pop cx
+5:
+    inc si
+    dec cl
+    jmp 1b
+0:
+    pop bp
+    pop bx
+    ret
+
+    # XXX: funky call
+    # inputs:
+    #   si: string offset
+    #   cl: string length
+    # clobbers: ax, bh, dx
+    .section .text.addtext
+addtext:
+    push di
+    push cx
+    mov bh, 0
+    mov ah, 0x03            # get cursor pos
+    int 0x10
+    pop cx
+    push dx
+    mov di, offset curpos
+    mov dx, [di]
+    mov ah, 0x02            # set cursor
+    int 0x10
+    call printn
+    mov ah, 0x03            # get cursor pos
+    int 0x10
+    mov [di], dx
+    pop dx
+    mov ah, 0x02            # set cursor
+    int 0x10
+    pop di
+    ret
+
+    .section .text.sendbuffer
+sendbuffer:
+    push bp
+    mov bp, sp
+    sub sp, 2
+    mov al, inputsize
+    mov [bp-2], al
+    movb inputsize, 0
+    mov si, offset .l0
+    mov cl, 2
+    call addtext
+    mov si, offset inputbuf
+    mov cl, [bp-2]
+    call addtext
+    mov si, offset .l1
+    mov cl, 2
+    call addtext
+    mov si, offset inputbuf
+    mov cl, [bp-2]
+    call parasend
+    # XXX: should check cx in case not everything was sent
+    mov al, ' '
+    mov dx, 0x1802      # [24; 2]
+    call drawchar
+    mov ah, 0x02 
+    int 0x10            # mov cursor back to start of line
+    add sp, 2
+    pop bp
+    ret
+
+    # draw until end of line
+    # al: char
+    # dh: row
+    # dl: start col
+    .section .text.drawchar
+drawchar:
+    push ax
+    mov bh, 0
+    mov ah, 0x02    # set cursor
+    int 0x10
+    mov cx, 80
+    sub cl, dl
+    pop ax
+    mov ah, 0x0a
+    int 0x10
+    ret
+
+    .section .text.parasend
+parasend:
+    mov ah, 0x06        # send parallel
+    push cx
+    push si
+    int 0x80
+    mov cx, 1
+    push cx
+    mov cx, offset .l1 + 1
+    push cx
+    mov ah, 0x06        # send parallel
+    int 0x80
+    add sp, 8
+    ret
+    
+prompt:
+    mov bh, 0
+    mov dx, 0x1800
+    mov ah, 0x02
+    int 0x10
+    mov ah, 0x0e
+    mov al, '>'
+    int 0x10
+    mov ah, 0x0e
+    mov al, ' '
+    int 0x10
+    ret
+
+    .section .rodata
+.l0: .ascii "> "
+.l1: .byte 0x0d, 0x0a
+.l2: .ascii "MUSHRoom 8086 client 0.1\r\n"
+l2len = . - offset .l2
+
+    .section .text.main
+    .global main
+main:
+    movb inputsize, 0       # inputsize = 0
+    movw curpos, 0          # mov buffer cursor to [0;0]
+    movb escaped, 0
+    mov ax, 0x0002
+    int 0x10
+    mov si, offset .l2
+    mov cl, l2len
+    call addtext
+    mov dx, 0x1700          # [23; 0]
+    mov al, 0xc4            # horizontal box line
+    call drawchar
+    call prompt
+0:
+    mov ah, 0x01
+    int 0x16                # check buffer
+    jz 1f                   # if empty, do a round of comms
+    mov ah, 0x00
+    int 0x16                # read 1 key
+    cmp al, 0x08            # backspace
+    je 5f
+    cmp al, 0x0d            # CR
+    je 4f
+    mov di, offset inputbuf        
+    mov si, offset inputsize
+    mov bh, 0
+    mov bl, [si]
+    cmp bl, kBufSize        # stop accepting input at end of screen
+    jge 1f                  # do a round of comms
+    mov [di+bx], al         # store character in buffer
+    incb [si]               # increment buffer size
+    mov ah, 0x0e
+    mov bh, 0
+    int 0x10                # local echo
+    jmp 0b
+5:
+    mov bl, inputsize
+    test bl, bl
+    jz 0b
+    decb inputsize
+    mov bh, 0
+    mov ah, 0x0e
+    int 0x10                # backspace
+    mov ax, 0x0e20
+    int 0x10
+    mov ax, 0x0e08
+    int 0x10
+    jmp 0b
+4:
+    call sendbuffer         # send input buffer
+1:
+    mov ah, 0x07            # do parallel comms
+    int 0x80
+    mov ax, kRecvBufSize
+    push ax
+    mov ax, offset recvbuf
+    push ax
+    mov ah, 0x05            # recv
+    int 0x80
+    test al, al
+    mov cl, al
+    pop si
+    pop bx
+    jz 0b
+    call addtext
+    jmp 0b

paracomm.c

@@ -1,6 +1,7 @@
 #include "paracomm.h"
 
 #include <stdlib.h>
+#include <string.h>
 
 #define kMosiIdleByte 0x00
 #define kMosiStartByte 0x42
@@ -21,7 +22,6 @@ static uint8_t miso_recvbuf[256];
 static uint8_t miso_size;
 static uint8_t miso_received_nibbles;
 static uint8_t miso_state;
-static void (*miso_cb)(const uint8_t*, uint8_t);
 
 static void swapbuffers() {
     mosi_sendbuf = mosi_workbuf[mosi_workbuf_idx];
@@ -92,23 +92,19 @@ void paracomm_feed(uint8_t n) {
         miso_received_nibbles += 1;
 
         if (miso_received_nibbles == 2 * miso_size) {
-            if (miso_cb != 0) {
-                miso_cb(miso_recvbuf, miso_size);
-            }
             miso_state = 0;
         }
     } break;
     }
 }
 
-void paracomm_init(miso_cb_t cb) {
+void paracomm_init() {
     mosi_size = 0;
     mosi_workbuf_idx = 0;
     mosi_workbuf_size = 0;
     mosi_state = 0;
 
     miso_state = 0;
-    miso_cb = cb;
 }
 
 int paracomm_send(uint8_t b) {
@@ -122,3 +118,21 @@ int paracomm_send(uint8_t b) {
 
     return 0;
 }
+
+uint8_t paracomm_recv(uint8_t* buf, uint8_t size) {
+    if (miso_state != 0) {
+        return 0;
+    }
+    if (size > miso_size) {
+        size = miso_size;
+    }
+    memcpy(buf, miso_recvbuf, size);
+    memcpy(miso_recvbuf, miso_recvbuf+size, miso_size - size);
+    miso_size -= size;
+
+    return size;
+}
+
+uint8_t paracomm_busy() {
+    return mosi_state != 0 || miso_state != 0;
+}

paracomm.h

@@ -2,18 +2,24 @@
 
 #include <stdint.h>
 
-typedef void (*miso_cb_t)(const uint8_t* buff, uint8_t size);
-
 /** Must call first **/
-void paracomm_init(miso_cb_t miso_cb);
+void paracomm_init();
 
 /** Sends a single byte.
  * Returns: 0 if no error, non-0 otherwise.
  */
 int paracomm_send(uint8_t b);
 
+/** Receive some bytes.
+ * Returns: number of bytes copied
+ */
+uint8_t paracomm_recv(uint8_t* buf, uint8_t size);
+
 /** Call after reading a nibble from the port */
 void paracomm_feed(uint8_t n);
 
 /** Yields the next byte to send out the port */
 uint8_t paracomm_nextbyte();
+
+/** Returns non-zero if busy */
+uint8_t paracomm_busy();

polio-main.c

@@ -0,0 +1,93 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fat12.h"
+#include "paracomm.h"
+
+#define kFatAddr ((void*)0x1a00)
+#define kRootDirAddr ((void*)0x1c00)
+#define kPolmonAddr ((void*)0x1000)
+#define kInt80Vector ((uint16_t*)(0x80 * 4))
+#define kParallelDataPort 0x3bc
+#define kParallelStatusPort 0x3bd
+#define kParallelControlPort 0x3be
+#define kParaDelay 400
+#define kRecvBufferSize 256
+
+void dosdbt();
+void int80h();
+
+uint8_t parabuf[kRecvBufferSize];
+uint8_t parasize;
+
+static void paracb(const uint8_t* buf, uint8_t size) {
+    // we'll mercilessly erase old data with new data
+    memcpy(parabuf, buf, size);
+    parasize = size;
+}
+
+static void die() {
+    while (1) {
+    }
+}
+
+static void __outb__(uint16_t port, uint8_t data) {
+    register uint16_t p asm("dx") = port;
+    register uint8_t d asm("al") = data;
+    asm volatile("outb %0, %1" ::"r"(d), "r"(p));
+}
+
+static uint8_t __inb__(uint16_t port) {
+    register uint16_t p asm("dx") = port;
+    register uint8_t d asm("al");
+    asm volatile("inb %1, %0" : "=r"(d) : "r"(p));
+    return d;
+}
+
+static void __delay__(int n) {
+    for (int i = 0; i < n; i++) {
+        asm volatile("");
+    }
+}
+
+uint8_t xferpara() {
+    uint8_t mosib = paracomm_nextbyte();
+    __outb__(kParallelDataPort, mosib);
+    __outb__(kParallelControlPort, 1);
+    __delay__(kParaDelay);
+    __outb__(kParallelControlPort, 0);
+    __delay__(kParaDelay);
+    uint8_t mison = __inb__(kParallelStatusPort) >> 4;
+    paracomm_feed(mison);
+
+    return paracomm_busy();
+}
+
+uint8_t parasend(uint8_t* addr, uint8_t size) {
+    uint8_t i;
+    for (i = 0; i < size; i++) {
+        if (paracomm_send(addr[i])) {
+            break;
+        }
+    }
+    return i;
+}
+
+int main() {
+    dosdbt();
+    parasize = 0;
+    paracomm_init(paracb);
+
+    fat12_init(kFatAddr, kRootDirAddr);
+
+    uint16_t* int80v = kInt80Vector;
+    int80v[0] = (uint16_t)int80h;
+    int80v[1] = 0;
+
+    if (fat12_readfile("POLMON  COM", kPolmonAddr)) {
+        die();
+    }
+
+    asm volatile("jmp *%0" ::"r"(kPolmonAddr));
+}

polio.s

@@ -5,6 +5,10 @@
     .section .init
     .global _start
 _start:
+    cli
+    mov ax, 0x2000      # stack address
+    mov sp, ax          # ss should already be 0
+    sti
     jmp main
 
 
@@ -12,7 +16,7 @@ diskpointer = 0x1e*4
 dbtbase = 0x0500
 
     .section .text.dosdbt
-    .local dosdbt
+    .global dosdbt
 dosdbt:                    # assumes es=0
     push si
     push di
@@ -36,8 +40,13 @@ dosdbt:                    # assumes es=0
 
     .section .text.int80stuff
 
-# near copy [param 2] bytes, es:[param 0] -> es:[param 1]
+# near copy [param 2] bytes, ds:[param 0] -> ds:[param 1]
 copy:
+    mov ax, [bp-14]     # ds
+    mov es, ax
+    mov ds, ax
+    mov cl, 4
+    shl si, cl
     mov si, [bp+0]      # source
     mov di, [bp+2]      # destination
     mov cx, [bp+4]      # length
@@ -103,51 +112,43 @@ formattrack:
     int 0x13
     ret
 
-
+# params: ds:fname, ds:dest
 readfile:
+    mov si, [bp-14] # ds
+    mov cl, 4
+    shl si, cl
     mov ax, [bp+0]
+    add ax, si
     mov dx, [bp+2]
+    add dx, si
     call fat12_readfile
     ret
 
+# params: ds:addr, size
+sendpara:
+    mov si, [bp-14] # ds
+    mov cl, 4
+    shl si, cl
+    mov ax, [bp+0]
+    add ax, si
+    mov dx, [bp+2]
+    call parasend
+    ret
 
-    .section .rodata.polmon_str
+# params: ds:addr, size
-polmon_str: .ascii "POLMON  COM"
+recvpara:
-polmon_addr = 0x1000
+    mov si, [bp-14] # ds
-
+    mov cl, 4
-    .section .text.main
+    shl si, cl
-    .global main
+    mov ax, [bp+0]
-main:
+    add ax, si
-    cli
+    mov dx, [bp+2]
-    mov ax, 0x2000      # stack address
+    call paracomm_recv
-    mov sp, ax          # ss should already be 0
+    ret
-    sti
-    call dosdbt
-    mov ax, 0x1a00      # first sector of first fat
-    mov dx, 0x1c00      # first sector of root dir
-    call fat12_init
-
-    mov si, 0x80*4
-    movw [si], offset int80h
-    movw [si+2], 0
-
-    mov ax, offset polmon_str 
-    mov dx, polmon_addr
-    call fat12_readfile
-    test ax, ax
-    jnz 0f
-
-    jmp polmon_addr
-0:
-    mov ax, 0x0e42
-    mov bh, 0
-    int 0x10
-    cli
-    hlt
 
     .section .text.int80h
+    .global int80h
 int80h:
-    push bx
     push si
     push di
     push bp
@@ -163,8 +164,8 @@ int80h:
     xor ah, ah
     mov si, ax
     mov bp, sp
-    lea bp, [bp + 18]       # 12 for us, 6 for the interrupt
+    lea bp, [bp + 16]       # 10 for us, 6 for the interrupt
-    call [int80h_table+si]
+    call cs:[int80h_table+si]
     jmp 1f
 0:
     mov ax, -1
@@ -174,10 +175,8 @@ int80h:
     pop bp
     pop di
     pop si
-    pop bx
     iret
 
-
     .section .rodata.int80h
 int80h_table:
     .word offset copy           # 0x00
@@ -185,5 +184,8 @@ int80h_table:
     .word offset writesector    # 0x02
     .word offset formattrack    # 0x03
     .word offset readfile       # 0x04
+    .word offset recvpara       # 0x05
+    .word offset sendpara       # 0x06
+    .word offset xferpara       # 0x07
 
 int80h_entries = . - int80h_table

polmon.cc

@@ -1,5 +1,6 @@
 #include <cstdint>
 #include <cstdio>
+#include <cstring>
 
 #ifndef WOZMON
 #define WOZMON 0
@@ -12,6 +13,8 @@
 #define INT80H 0
 #define SHOWTITLE 0
 #define BOOTSTRAP 0
+#define LAUNCH 0
+#define CTRLBREAK 0
 #endif  // WOZMON
 
 #ifndef BACKSPACE
@@ -38,6 +41,14 @@
 #define BOOTSTRAP 1
 #endif
 
+#ifndef LAUNCH
+#define LAUNCH 1
+#endif
+
+#ifndef CTRLBREAK
+#define CTRLBREAK 1
+#endif
+
 namespace {
 
 #if WOZMON
@@ -213,6 +224,97 @@ void Status(uint8_t status) {
                  : "ax", "bh", "dx", "cx", "di", "cc");
 }
 
+char toupper(char c) {
+    if (c >= 'a' && c <= 'z') {
+        return c - ('a' - 'A');
+    }
+    return c;
+}
+
+void tofatname(const char* name, char* fatname) {
+    for (int i = 0; i < 11; i++) {
+        if (*name == 0 || *name == '.') {
+            fatname[i] = ' ';
+        } else {
+            fatname[i] = toupper(*name++);
+        }
+        if (i == 7 && *name == '.') {
+            name++;
+        }
+    }
+}
+
+void LaunchFile(const char* name) {
+    constexpr uint16_t kSegment = 0x200;
+    constexpr uint16_t kAddress = 0x100;
+    constexpr uint16_t kHeaderAddress = (kSegment << 4);
+    constexpr uint16_t kFlatAddress = (kSegment << 4) + kAddress;
+    constexpr uint8_t kTrampoline[] = { 0xe8, 0xfd, 0x00, 0xcb };
+
+    char fatname[11];
+    tofatname(name, fatname);
+
+    auto* ptr = reinterpret_cast<uint8_t*>(kHeaderAddress);
+    memcpy(ptr, kTrampoline, sizeof(kTrampoline));
+
+    asm volatile("mov %1, %%ax      \n\t"
+                 "push %%ax         \n\t"
+                 "mov %0, %%ax      \n\t"
+                 "push %%ax         \n\t"
+                 "mov $04, %%ah     \n\t"
+                 "int $0x80         \n\t"
+                 "add $4, %%sp      \n\t"
+                 "mov %2, %%ax      \n\t"
+                 "mov %%ax, %%ds    \n\t"
+                 "mov %%ax, %%es    \n\t"
+                 "cli               \n\t"
+                 "mov %%ax, %%ss    \n\t"
+                 "mov %3, %%ax      \n\t"
+                 "xchg %%ax, %%sp   \n\t"
+                 "sti               \n\t"
+                 "push %%ax         \n\t"
+                 "lcall %2,$0       \n\t"
+                 "xor %%ax, %%ax    \n\t"
+                 "mov %%ax, %%ds    \n\t"
+                 "mov %%ax, %%es    \n\t"
+                 "cli               \n\t"
+                 "pop %%sp          \n\t"
+                 "mov %%ax, %%ss    \n\t"
+                 "sti"
+                 :: "rmi"(fatname),
+                 "rmi"(kFlatAddress), "i"(kSegment), "i"(kHeaderAddress)
+                 : "ax", "bx", "cx", "dx", "memory");
+}
+
+#if CTRLBREAK
+
+constexpr uint16_t kCtrlBreakVector = (0x1b * 4);
+
+extern "C" void cbreak();
+asm("   .section .text.cbreak   \n"
+    "cbreak:                \n"
+    "   xor %ax, %ax        \n"
+    "   mov %ds, %ax        \n"
+    "   cli                 \n"
+    "   mov %ss, %ax        \n"
+    "   mov $0x2000, %sp    \n"
+    "   sti                 \n"
+    "   pushf               \n"
+    "   push %ax            \n"
+    "   mov $0x1000, %ax    \n"
+    "   push %ax            \n"
+    "   mov $0x20, %al      \n"
+    "   out %al, $0x20      \n"
+    "   iret                \n");
+
+void InstallCtrlBreak() {
+    auto vec = reinterpret_cast<void (**)()>(kCtrlBreakVector);
+    vec[0] = cbreak;
+    vec[1] = 0;
+}
+
+#endif  // CTRLBREAK
+
 bool ParseCommand(const char* buf, uint16_t& cur_addr, uint16_t& cur_seg) {
     bool dump = true;
     for (const char* ptr = buf; *ptr;) {
@@ -259,7 +361,20 @@ bool ParseCommand(const char* buf, uint16_t& cur_addr, uint16_t& cur_seg) {
             dump = false;
             ClearScreen();
             ptr++;
-#endif
+#endif  // CLEARSCREENCMD
+#if LAUNCH
+        } else if (*ptr == 'r') {
+            dump = false;
+            ptr++;
+            while (*ptr == ' ') {
+                ptr++;
+            }
+            int l = 0;
+            for (; ptr[l]; l++) {
+            }
+            LaunchFile(ptr);
+            ptr += l;
+#endif  // LAUNCH
         } else if (*ptr == 'w') {
             dump = false;
             uint16_t addr = cur_addr;
@@ -296,7 +411,7 @@ void polmon() {
 
     ClearScreen();
 #if SHOWTITLE
-    puts("PolMon 0.2\r\n");
+    puts("PolMon for Workgroups 3.1\r\n");
 #endif  // SHOWTITLE
     DisplayPrompt();
 
@@ -339,7 +454,12 @@ void polmon() {
 
 }  // namespace
 
-int main() { polmon(); }
+int main() {
+#if CTRLBREAK
+    InstallCtrlBreak();
+#endif  // CTRLBREAK
+    polmon();
+}
 
 #if BOOTSTRAP
 __attribute__((section(".init"), noreturn, used)) void _start() {

runcomm.asm

@@ -0,0 +1,10 @@
+CPU 8086
+
+mov cx, 0x100
+a:
+    mov ah, 0x07
+    int 0x80
+    test al, al
+    loopnz a
+b:
+    ret

stdlib.c

@@ -1,3 +1,6 @@
+#include <stdint.h>
+#include <stdlib.h>
+
 int getchar() {
     register char c asm("al");
     asm volatile("movb $0x00, %%ah\n\t"
@@ -23,3 +26,20 @@ int puts(const char* s) {
     }
     return 0;
 }
+
+void* memcpy(void* dest, const void* src, size_t n) {
+    uint8_t* d = dest;
+    const uint8_t* s = src;
+    for (int i = 0; i < n; i++) {
+        d[i] = s[i];
+    }
+    return dest;
+}
+
+void* memset(void* ptr, int val, size_t len) {
+    uint8_t* p = ptr;
+    while (len--) {
+        *p++ = val;
+    }
+    return ptr;
+}

trampoline.asm

@@ -0,0 +1,13 @@
+CPU 8086
+
+src equ 0xf000
+dest equ 0x0600
+size equ 0x0600
+
+_start:
+    mov cx, size
+    mov si, src
+    mov di, dest
+    rep movsb
+    mov ax, dest
+    jmp ax