during development of my NC200 emulation for M.E.S.S.
This update does not cover the NC150. I do not have details of any differencesbetween this and the NC100 at this time.
When I have information on this system, it will be documented here.
of I/O read/writes.
* The NC200 does not have a TC8521 Real Time Clock, instead ithas a MC146818 Real Time Clock. The MC146818 is no longer produced now,but is part of many PC designs.
* The NC200 has a [[NEC765 ]] compatible floppy disc controller. The discinterface was designed by Ranger Computers.
The ports listed in this section are different or have additional
* The NC100 clock speed is 4.606Mhz606MHz, at this time it is unknown if the NC200has a different clock speed. * The NC100 on/off button generates an NMI.* The NC200 on/off button generates a maskable interrupt. Keyboard NC100: B0: bit 0: Shift (Left) bit 1: Shift (Right) bit 2: unused bit 3: Cursor Left (Red) bit 4: Return bit 5: unused bit 6: unused bit 7: unused B1: bit 0: Function (Yellow) bit 1: Control bit 2: Stop bit 3: Space bit 4: unused bit 5: unused bit 6: 5 bit 7: unused B2: bit 0: Caps Lock bit 1: Symbol bit 2: 1 bit 3: Tab bit 4: unused bit 5: unused bit 6: unused bit 7: unused B3: bit 0: 3 bit 1: 2 bit 2: Q bit 3: W bit 4: E bit 5: unused bit 6: S bit 7: D B4: bit 0: 4 bit 1: unused bit 2: Z bit 3: X bit 4: A bit 5: unused bit 6: R bit 7: F B5: bit 0: ?? bit 1: ?? bit 2: B bit 3: V bit 4: T bit 5: Y bit 6: G bit 7: C B6: bit 0: 6 bit 1: Cursor Down (Blue) bit 2: Del bit 3: Cursor Right (Green) bit 4: \ bit 5: / bit 6: H bit 7: N B7: bit 0: = bit 1: 7 bit 2: ~ bit 3: Up bit 4: Menu bit 5: U bit 6: M bit 7: K B8: bit 0: 8 bit 1: - bit 2: ) bit 3: ( bit 4: " bit 5: I bit 6: J bit 7: , B9: bit 0: 0 bit 1: 9 bit 2: Del bit 3: P bit 4: : bit 5: L bit 6: O bit 7: .
Address Comment R/W
======= ======= ===
00 Display Memory start W
20 Memory card wait state W
bit 7: memory card wait state control: 1 for wait states, 0 for no wait
bit 2: ??
bit 1: ??
bit 0: NEC765 Terminal Count input (1=TC active, 0=TC inactive)
Address = 30 Write only
Floppy motor control
bit 3: Floppy motor: 1=off, 0=on
Address = 70
bit 2: Backlight: 1=off, 0=on
bit 1: ??
bit 0: on/off control: 1 = on, 0 = off
Address = 80
centronics status
bit 0: busy state
Address = A0
E1 = data
[[http://groups.google.com/group/comp.sys.amstrad.8bit/browse_thread/thread/ce201414eff39a29/19cb6f7056d49480?lnk=gst&q=nc100+sound#19cb6f7056d49480| Russell Marks's notes about sound generation on NC100]]
[[NC100 IO Specification]]
[[Category:NC Series]]