diff options
Diffstat (limited to 'src/mess/drivers/pdp11.c')
-rw-r--r-- | src/mess/drivers/pdp11.c | 50 |
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) |