diff --git a/src/cdrom/cdrom_mke.c b/src/cdrom/cdrom_mke.c
index 91765f8ab..a8f6155e7 100644
--- a/src/cdrom/cdrom_mke.c
+++ b/src/cdrom/cdrom_mke.c
@@ -121,11 +121,11 @@ typedef struct mke_t {
     uint32_t data_to_push;
 
     pc_timer_t timer;
+
+    uint8_t *ver;
 } mke_t;
 mke_t mke;
 
-static uint8_t ver[10] = "CR-5630.75";
-
 #ifdef ENABLE_MKE_LOG
 int mke_do_log = ENABLE_MKE_LOG;
 
@@ -144,8 +144,8 @@ mke_log(const char *fmt, ...)
 #    define mke_log(fmt, ...)
 #endif
 
-#define CHECK_READY()                                      \
-    {                                                      \
+#define CHECK_READY()                                       \
+    {                                                       \
         if (mke->cdrom_dev->cd_status == CD_STATUS_EMPTY) { \
             fifo8_push(&mke->errors_fifo, 0x03);            \
             return;                                         \
@@ -614,7 +614,7 @@ mke_command(mke_t *mke, uint8_t value)
             case CMD1_READ_VER:
                 /* SB2CD Expects 12 bytes, but drive only returns 11. */
                 fifo8_reset(&mke->info_fifo);
-                fifo8_push_all(&mke->info_fifo, ver, 10);
+                fifo8_push_all(&mke->info_fifo, mke->ver, 10);
                 fifo8_push(&mke->info_fifo, mke_cdrom_status(mke->cdrom_dev, mke));
                 break;
             case CMD1_STATUS:
@@ -773,6 +773,22 @@ mke_init(const device_t *info)
     if (!dev)
         return NULL;
 
+    switch (device_get_config_int("firmware")) {
+        default:
+        case 0:
+            mke->ver = "CR-5630.75";
+            break;
+        case 1:
+            mke->ver = "CR-5630.80";
+            break;
+        case 2:
+            mke->ver = "CR-5620.75";
+            break;
+        case 3:
+            mke->ver = "CR-5620.80";
+            break;
+    }
+
     fifo8_create(&mke->info_fifo, 128);
     fifo8_create(&mke->data_fifo, 624240 * 2);
     fifo8_create(&mke->errors_fifo, 8);
@@ -829,6 +845,23 @@ static const device_config_t mke_config[] = {
         },
         .bios           = { { 0 } }
     },
+    {
+        .name           = "firmware",
+        .description    = "Firmware Version",
+        .type           = CONFIG_SELECTION,
+        .default_string = NULL,
+        .default_int    = 0,
+        .file_filter    = NULL,
+        .spinner        = { 0 },
+        .selection      = {
+            { .description = "CR-563 0.75", .value = 0 },
+            { .description = "CR-563 0.80", .value = 1 },
+            { .description = "CR-562 0.75", .value = 2 },
+            { .description = "CR-562 0.80", .value = 3 },
+            { .description = ""                        }
+        },
+        .bios           = { { 0 } }
+    },
     { .name = "", .description = "", .type = CONFIG_END }
 // clang-format off
 };
diff --git a/src/chipset/scamp.c b/src/chipset/scamp.c
index 855175dcd..7ad7b3db2 100644
--- a/src/chipset/scamp.c
+++ b/src/chipset/scamp.c
@@ -840,7 +840,7 @@ recalc_sltptr(scamp_t *dev)
             recalc_ems(dev);
         }
     } else {
-        for (uint8_t i = 0; i < (sltptr / EMS_PGSIZE); i++)
+        for (uint32_t i = 0; i < (sltptr / EMS_PGSIZE); i++)
             scamp_mem_update_state(dev, i * EMS_PGSIZE, EMS_PGSIZE, 0x00, MEM_FMASK_SLOTBUS);
 
         for (uint8_t i = (sltptr / EMS_PGSIZE); i < 40; i++)
diff --git a/src/chipset/wd76c10.c b/src/chipset/wd76c10.c
index 48bb56483..bc3b4324c 100644
--- a/src/chipset/wd76c10.c
+++ b/src/chipset/wd76c10.c
@@ -841,7 +841,7 @@ wd76c10_pf_loc_recalc(wd76c10_t *dev)
     uint8_t ems_page;
     uint32_t base;
 
-    for (uint8_t i = (0x031 + pf_loc); i <= (0x037 + pf_loc); i++) {
+    for (uint16_t i = (0x031 + pf_loc); i <= (0x037 + pf_loc); i++) {
         ems_page = (i - 0x10) & 0xf7;
         dev->mem_pages[i] = ems_page;
         base = ((uint32_t) i) << 14;
diff --git a/src/cpu/808x.c b/src/cpu/808x.c
index edab16567..14e56f23a 100644
--- a/src/cpu/808x.c
+++ b/src/cpu/808x.c
@@ -539,10 +539,9 @@ pfq_write(void)
 static uint8_t
 pfq_read(void)
 {
-    uint8_t temp, i;
+    uint8_t temp = pfq[0];
 
-    temp = pfq[0];
-    for (i = 0; i < (pfq_size - 1); i++)
+    for (int i = 0; i < (pfq_size - 1); i++)
         pfq[i] = pfq[i + 1];
     pfq_pos--;
     cpu_state.pc = (cpu_state.pc + 1) & 0xffff;
diff --git a/src/qt/qt_openglrenderer.cpp b/src/qt/qt_openglrenderer.cpp
index f1fa5eecf..4ec091eb2 100644
--- a/src/qt/qt_openglrenderer.cpp
+++ b/src/qt/qt_openglrenderer.cpp
@@ -595,7 +595,7 @@ load_texture(const char *f, struct shader_texture *tex)
 
     int bpp = 4;
 
-    GLubyte *data = (GLubyte *) malloc(width * height * bpp);
+    GLubyte *data = (GLubyte *) malloc((size_t) width * height * bpp);
 
     int x, y, Y;
     for (y = 0; y < height; ++y) {
@@ -1709,7 +1709,7 @@ OpenGLRenderer::render()
         plat_tempfile(fn, NULL, (char*)".png");
         strcat(path, fn);
 
-        unsigned char *rgba = (unsigned char *)calloc(1, width * height * 4);
+        unsigned char *rgba = (unsigned char *) calloc(1, (size_t) width * height * 4);
         
         glw.glFinish();
         glw.glReadPixels(window_rect.x, window_rect.y, width, height, GL_RGBA, GL_UNSIGNED_BYTE, rgba);
diff --git a/src/sound/midi_opl4.c b/src/sound/midi_opl4.c
index 5ec15cc7c..25f44c9e7 100644
--- a/src/sound/midi_opl4.c
+++ b/src/sound/midi_opl4.c
@@ -436,7 +436,8 @@ note_on(uint8_t note, uint8_t velocity, MIDI_CHANNEL_DATA *midi_channel, opl4_mi
     const YRW801_REGION_DATA_PTR *region_ptr = &snd_yrw801_regions[0];
     const YRW801_WAVE_DATA       *wave_data[2];
     VOICE_DATA                   *voice[2];
-    uint8_t                       i = 0, voices = 0;
+    int                           i      = 0;
+    uint8_t                       voices = 0;
 
     while (opl4_midi->gen_in_progress) { }
 
diff --git a/src/video/vid_bochs_vbe.c b/src/video/vid_bochs_vbe.c
index fd5772b19..0ea268ef7 100644
--- a/src/video/vid_bochs_vbe.c
+++ b/src/video/vid_bochs_vbe.c
@@ -511,7 +511,7 @@ bochs_vbe_outw(const uint16_t addr, const uint16_t val, void *priv)
                 svga_recalctimings(&dev->svga);
                 if (!(val & VBE_DISPI_NOCLEARMEM)) {
                     memset(dev->svga.vram, 0,
-                           dev->vbe_regs[VBE_DISPI_INDEX_YRES] * dev->svga.rowoffset);
+                           (size_t) dev->vbe_regs[VBE_DISPI_INDEX_YRES] * dev->svga.rowoffset);
                 }
             } else
                 dev->svga.read_bank = dev->svga.write_bank = 0;
diff --git a/src/video/vid_svga.c b/src/video/vid_svga.c
index 3e20efb05..113a8984f 100644
--- a/src/video/vid_svga.c
+++ b/src/video/vid_svga.c
@@ -1212,7 +1212,7 @@ svga_recalctimings(svga_t *svga)
             int y_start = enable_overscan ? 0 : (svga->monitor->mon_overscan_y >> 1);
             int x_start = enable_overscan ? 0 : (svga->monitor->mon_overscan_x >> 1);
             video_wait_for_buffer_monitor(svga->monitor_index);
-            memset(svga->monitor->target_buffer->dat, 0, svga->monitor->target_buffer->w * svga->monitor->target_buffer->h * 4);
+            memset(svga->monitor->target_buffer->dat, 0, (size_t) svga->monitor->target_buffer->w * svga->monitor->target_buffer->h * 4);
             video_blit_memtoscreen_monitor(x_start, y_start, svga->monitor->mon_xsize + x_add, svga->monitor->mon_ysize + y_add, svga->monitor_index);
             video_wait_for_buffer_monitor(svga->monitor_index);
             svga->dpms_ui = 1;
diff --git a/src/video/vid_svga_render.c b/src/video/vid_svga_render.c
index b3a5c0192..da1c0d001 100644
--- a/src/video/vid_svga_render.c
+++ b/src/video/vid_svga_render.c
@@ -746,7 +746,7 @@ svga_render_indexed_gfx(svga_t *svga, bool highres, bool combine8bits)
 
     if (svga->render_line_offset) {
         if (svga->render_line_offset > 0) {
-            memset(p, svga->overscan_color, charwidth * svga->render_line_offset * sizeof(uint32_t));
+            memset(p, svga->overscan_color, (size_t) charwidth * svga->render_line_offset * sizeof(uint32_t));
             p += charwidth * svga->render_line_offset;
         }
     }
@@ -911,7 +911,7 @@ svga_render_indexed_gfx(svga_t *svga, bool highres, bool combine8bits)
     if (svga->render_line_offset < 0) {
         uint32_t *orig_line = &svga->monitor->target_buffer->line[svga->displine + svga->y_add][svga->x_add];
         memmove(orig_line, orig_line + (charwidth * -svga->render_line_offset), (svga->hdisp) * 4);
-        memset((orig_line + svga->hdisp) - (charwidth * -svga->render_line_offset), svga->overscan_color, charwidth * -svga->render_line_offset * 4);
+        memset((orig_line + svga->hdisp) - (charwidth * -svga->render_line_offset), svga->overscan_color, (size_t) charwidth * -svga->render_line_offset * 4);
     }
 }
 
diff --git a/src/video/video.c b/src/video/video.c
index 785479e15..c8dc137c5 100644
--- a/src/video/video.c
+++ b/src/video/video.c
@@ -1058,20 +1058,20 @@ loadfont_common(FILE *fp, int format)
                 for (uint16_t c = d; c < d + 256; c++) {
                     (void) !fread(&fontdatm[c][8], 1, 8, fp);
                 }
-                for (uint16_t c = d + 256; c < d + 512; c++) {
+                for (uint32_t c = d + 256; c < d + 512; c++) {
                     (void) !fread(&fontdatm[c][8], 1, 8, fp);
                 }
-                for (uint16_t c = d; c < d + 256; c++) {
+                for (uint32_t c = d; c < d + 256; c++) {
                     (void) !fread(&fontdatm[c][0], 1, 8, fp);
                 }
-                for (uint16_t c = d + 256; c < d + 512; c++) {
+                for (uint32_t c = d + 256; c < d + 512; c++) {
                     (void) !fread(&fontdatm[c][0], 1, 8, fp);
                 }
                 fseek(fp, 4096, SEEK_CUR); /* Skip blank section */
-                for (uint16_t c = d; c < d + 256; c++) {
+                for (uint32_t c = d; c < d + 256; c++) {
                     (void) !fread(&fontdat[c][0], 1, 8, fp);
                 }
-                for (uint16_t c = d + 256; c < d + 512; c++) {
+                for (uint32_t c = d + 256; c < d + 512; c++) {
                     (void) !fread(&fontdat[c][0], 1, 8, fp);
                 }
             }