summaryrefslogtreecommitdiffstatshomepage
path: root/src/mess/drivers/pdp11.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/mess/drivers/pdp11.c')
-rw-r--r--src/mess/drivers/pdp11.c50
1 files changed, 25 insertions, 25 deletions
diff --git a/src/mess/drivers/pdp11.c b/src/mess/drivers/pdp11.c
index 7cb308e2d1e..f6904ddafff 100644
--- a/src/mess/drivers/pdp11.c
+++ b/src/mess/drivers/pdp11.c
@@ -64,22 +64,22 @@
23/02/2009 Skeleton driver.
- Memory Map (converted from the annoying octal format from the manuals):
- 0x0000 - 0x00ff: irq vectors
- 0xe000: ROM
- 0xff68: "high speed reader and punch device status and buffer register"
- 0xff70 - 0xff7e: "teletype keyboard and punch device status and buffer register"
- PDP-11 internal registers:
- 0xff80 - 0xffbf: "reserved for expansion of processor registers"
- 0xffc0: R0
- 0xffc2: R1
- 0xffc4: R2
- 0xffc6: R3
- 0xffc8: R4
- 0xffca: R5
- 0xffcc: R6 / SP
- 0xffce: R7 / PC
- 0xfffe: PSW
+ Memory Map (converted from the annoying octal format from the manuals):
+ 0x0000 - 0x00ff: irq vectors
+ 0xe000: ROM
+ 0xff68: "high speed reader and punch device status and buffer register"
+ 0xff70 - 0xff7e: "teletype keyboard and punch device status and buffer register"
+ PDP-11 internal registers:
+ 0xff80 - 0xffbf: "reserved for expansion of processor registers"
+ 0xffc0: R0
+ 0xffc2: R1
+ 0xffc4: R2
+ 0xffc6: R3
+ 0xffc8: R4
+ 0xffca: R5
+ 0xffcc: R6 / SP
+ 0xffce: R7 / PC
+ 0xfffe: PSW
****************************************************************************/
@@ -117,19 +117,19 @@ READ16_MEMBER(pdp11_state::teletype_ctrl_r)
switch(offset)
{
/*
- keyboard
- ---- x--- ---- ---- busy bit
- ---- ---- x--- ---- ready bit (set on character receive, clear on buffer read)
- ---- ---- -x-- ---- irq enable
- ---- ---- ---- ---x reader enable (?)
+ keyboard
+ ---- x--- ---- ---- busy bit
+ ---- ---- x--- ---- ready bit (set on character receive, clear on buffer read)
+ ---- ---- -x-- ---- irq enable
+ ---- ---- ---- ---x reader enable (?)
*/
case 0: res = m_teletype_status; break; // reader status register (tks)
case 1: m_teletype_status &= ~0x80; res = m_teletype_data; break;// reader buffer register (tkb)
/*
- printer
- ---- ---- x--- ---- ready bit
- ---- ---- -x-- ---- irq enable
- ---- ---- ---- -x-- maintenance
+ printer
+ ---- ---- x--- ---- ready bit
+ ---- ---- -x-- ---- irq enable
+ ---- ---- ---- -x-- maintenance
*/
case 2: res = 0x80; break; // punch status register (tps)
case 3: res = 0; break; // punch buffer register (tpb)