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-rw-r--r--src/mess/machine/nextmo.c197
1 files changed, 197 insertions, 0 deletions
diff --git a/src/mess/machine/nextmo.c b/src/mess/machine/nextmo.c
new file mode 100644
index 00000000000..a79fc9cfbf4
--- /dev/null
+++ b/src/mess/machine/nextmo.c
@@ -0,0 +1,197 @@
+
+#include "emu.h"
+#include "nextmo.h"
+
+const device_type NEXTMO = &device_creator<nextmo_device>;
+
+DEVICE_ADDRESS_MAP_START(map, 8, nextmo_device)
+ AM_RANGE(0x04, 0x04) AM_READWRITE(r4_r, r4_w)
+ AM_RANGE(0x05, 0x05) AM_READWRITE(r5_r, r5_w)
+ AM_RANGE(0x06, 0x06) AM_READWRITE(r6_r, r6_w)
+ AM_RANGE(0x07, 0x07) AM_READWRITE(r7_r, r7_w)
+ AM_RANGE(0x08, 0x08) AM_READWRITE(r8_r, r8_w)
+ AM_RANGE(0x09, 0x09) AM_READWRITE(r9_r, r9_w)
+ AM_RANGE(0x0a, 0x0a) AM_READWRITE(ra_r, ra_w)
+ AM_RANGE(0x0b, 0x0b) AM_READWRITE(rb_r, rb_w)
+ AM_RANGE(0x10, 0x17) AM_READWRITE(r10_r, r10_w)
+ADDRESS_MAP_END
+
+nextmo_device::nextmo_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
+ : device_t(mconfig, NEXTMO, "NeXT Magneto-optical drive", tag, owner, clock)
+{
+}
+
+void nextmo_device::set_cb(line_cb_t _irq_cb, line_cb_t _drq_cb)
+{
+ irq_cb = _irq_cb;
+ drq_cb = _drq_cb;
+}
+
+void nextmo_device::device_start()
+{
+}
+
+void nextmo_device::device_reset()
+{
+}
+
+READ8_MEMBER(nextmo_device::r4_r)
+{
+ logerror("nextmo: r4_r %02x (%08x)\n", r4, cpu_get_pc(&space.device()));
+ return r4;
+}
+
+WRITE8_MEMBER(nextmo_device::r4_w)
+{
+ if(r4 & 1)
+ device_reset();
+ r4 = (r4 & (~data & 0xfc)) | (data & 3);
+ logerror("nextmo: r4_w %02x (%08x)\n", r4, cpu_get_pc(&space.device()));
+}
+
+READ8_MEMBER(nextmo_device::r5_r)
+{
+ logerror("nextmo: r5_r %02x (%08x)\n", r5, cpu_get_pc(&space.device()));
+ return r5;
+}
+
+WRITE8_MEMBER(nextmo_device::r5_w)
+{
+ r5 = data;
+ logerror("nextmo: r5_w %02x (%08x)\n", r5, cpu_get_pc(&space.device()));
+}
+
+READ8_MEMBER(nextmo_device::r6_r)
+{
+ logerror("nextmo: r6_r %02x (%08x)\n", r6, cpu_get_pc(&space.device()));
+ return r6;
+}
+
+WRITE8_MEMBER(nextmo_device::r6_w)
+{
+ r6 = data;
+ logerror("nextmo: r6_w %02x (%08x)\n", r6, cpu_get_pc(&space.device()));
+}
+
+READ8_MEMBER(nextmo_device::r7_r)
+{
+ logerror("nextmo: r7_r %02x (%08x)\n", r7, cpu_get_pc(&space.device()));
+ return r7;
+}
+
+WRITE8_MEMBER(nextmo_device::r7_w)
+{
+ r7 = data;
+ logerror("nextmo: r7_w %02x (%08x)\n", r7, cpu_get_pc(&space.device()));
+ if(r7 & 0xc0) {
+ logerror("nextmo: start dma %02x %02x\n", r6, r7);
+ sector_pos = 0;
+ if(!drq_cb.isnull())
+ drq_cb(true);
+ }
+}
+
+UINT8 nextmo_device::dma_r()
+{
+ UINT8 r = 0;
+ if(r7 & 0x80)
+ r = sector[sector_pos++];
+ check_dma_end();
+ return r;
+}
+
+void nextmo_device::dma_w(UINT8 data)
+{
+ if(r7 & 0x40)
+ sector[sector_pos++] = data;
+ check_dma_end();
+}
+
+void nextmo_device::check_dma_end()
+{
+ int limit;
+ if(r7 & 0x40)
+ limit = r6 & 0x20 ? 0x510 : 0x400;
+ else
+ limit = r6 & 0x20 ? 0x400 : 0x510;
+ if(sector_pos == limit) {
+ if(!drq_cb.isnull())
+ drq_cb(false);
+ if(r7 & 0x40) {
+ if(r6 & 0x20)
+ check_ecc();
+ else
+ compute_ecc();
+ }
+ r7 &= 0x3f;
+ r4 |= 0x08;
+ }
+}
+
+READ8_MEMBER(nextmo_device::r8_r)
+{
+ logerror("nextmo: r8_r (%08x)\n", cpu_get_pc(&space.device()));
+ return 0x00;
+}
+
+WRITE8_MEMBER(nextmo_device::r8_w)
+{
+ logerror("nextmo: r8_w %02x (%08x)\n", data, cpu_get_pc(&space.device()));
+}
+
+READ8_MEMBER(nextmo_device::r9_r)
+{
+ logerror("nextmo: r9_r (%08x)\n", cpu_get_pc(&space.device()));
+ return 0x00;
+}
+
+WRITE8_MEMBER(nextmo_device::r9_w)
+{
+ logerror("nextmo: r9_w %02x (%08x)\n", data, cpu_get_pc(&space.device()));
+}
+
+READ8_MEMBER(nextmo_device::ra_r)
+{
+ logerror("nextmo: ra_r (%08x)\n", cpu_get_pc(&space.device()));
+ return 0x00;
+}
+
+WRITE8_MEMBER(nextmo_device::ra_w)
+{
+ logerror("nextmo: ra_w %02x (%08x)\n", data, cpu_get_pc(&space.device()));
+}
+
+READ8_MEMBER(nextmo_device::rb_r)
+{
+ logerror("nextmo: rb_r (%08x)\n", cpu_get_pc(&space.device()));
+ return 0x24;
+}
+
+WRITE8_MEMBER(nextmo_device::rb_w)
+{
+ logerror("nextmo: rb_w %02x (%08x)\n", data, cpu_get_pc(&space.device()));
+}
+
+READ8_MEMBER(nextmo_device::r10_r)
+{
+ logerror("nextmo: r10_r %d (%08x)\n", offset, cpu_get_pc(&space.device()));
+ return 0x00;
+}
+
+WRITE8_MEMBER(nextmo_device::r10_w)
+{
+ logerror("nextmo: r10_w %d, %02x (%08x)\n", offset, data, cpu_get_pc(&space.device()));
+}
+
+void nextmo_device::check_ecc()
+{
+ logerror("nextmo: check_ecc\n");
+ for(int i=0; i<0x400; i++)
+ sector[i] = i;
+}
+
+void nextmo_device::compute_ecc()
+{
+ logerror("nextmo: compute_ecc\n");
+ memset(sector+0x400, 0, 0x110);
+}