From 52f299f6160e3027e91ba4710d50d4e1efab8ed0 Mon Sep 17 00:00:00 2001 From: AJR Date: Sat, 18 May 2019 17:14:00 -0400 Subject: atari810, atari1050: Add notes on format; correct mirroring (nw) --- src/devices/bus/a800/atari1050.cpp | 12 +++++++++++- src/devices/bus/a800/atari810.cpp | 8 ++++++++ 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/src/devices/bus/a800/atari1050.cpp b/src/devices/bus/a800/atari1050.cpp index b3ed498bba3..12191d4cc72 100644 --- a/src/devices/bus/a800/atari1050.cpp +++ b/src/devices/bus/a800/atari1050.cpp @@ -4,6 +4,16 @@ Atari 1050 Dual Density Disk Drive + This SIO peripheral device controls one 5¼" floppy disk drive. Two + soft-sectored data formats are supported: + * Single density: FM, 40 tracks, 18 sectors/track (88K bytes) + * Double density: MFM, 40 tracks, 26 sectors/track (133K bytes; + requires DOS3) + + As with the 810, the 1050 uses parallel port outputs to operate the + drive mechanism's four-phase stepper motor at 288 RPM. The FDC's own + stepping outputs are not used, and its index pulse is synthesized. + ***************************************************************************/ #include "emu.h" @@ -37,7 +47,7 @@ void atari1050_device::mem_map(address_map &map) map(0x0000, 0x007f).mirror(0x0900).ram(); // MCM6810 map(0x0080, 0x00ff).mirror(0x0900).m(m_pia, FUNC(mos6532_new_device::ram_map)); map(0x0280, 0x029f).mirror(0x0960).m(m_pia, FUNC(mos6532_new_device::io_map)); - map(0x0400, 0x0403).mirror(0x087c).rw(m_fdc, FUNC(wd2793_device::read), FUNC(wd2793_device::write)); + map(0x0400, 0x0403).mirror(0x0bfc).rw(m_fdc, FUNC(wd2793_device::read), FUNC(wd2793_device::write)); map(0x1000, 0x1fff).rom().region("rom", 0); } diff --git a/src/devices/bus/a800/atari810.cpp b/src/devices/bus/a800/atari810.cpp index 6967d641753..69b5bd09d2f 100644 --- a/src/devices/bus/a800/atari810.cpp +++ b/src/devices/bus/a800/atari810.cpp @@ -4,6 +4,14 @@ Atari 810 Disk Drive + The 810 is the original 5¼" floppy disk interface for the Atari 400/800 + computer, supporting only a 709-sector single density format. + + The built-in drive mechanism uses a four-phase stepper motor which is + controlled by outputs to a PIA port rather than by the WD1771-01 FDC. + The PIA also generates a synthetic index pulse for the FDC. (The format + defines the undersized 19th sector of each track as the index area.) + ***************************************************************************/ #include "emu.h" -- cgit v1.2.3