Changes
guarantee about this.
Cliff Lawson CIS: 75300,1517 Notepad project manager email: cliffl@amstrad.com Amstrad Plc amstrad@cix.compulink.co.uk 169 Kings Road Phone: (+44) 277 208341 Brentwood Fax: (+44) 277 208065 Essex CM14 4EF ENGLAND
I/O Specification for Amstrad NC100
All numbers are in hexadecimal unless suffixed with a "b" for binary or
"d" for decimal. (Address line numbers A19, A18, etc are in decimal).
SUMMARY
Address Comment R/W
E0-FF Not Used - D0-DF RTC (TC8521) R/W C0-C1 UART (uPD71051) R/W B0-B9 Key data in R A0 Card Status etc. R 90 IRQ request status R/W 80-8F Not Used 70 Power on/off control W 60 IRQ Mask W 50-53 Speaker frequency W 40 Parallel port data W 30 Baud rate etc. W 20 Card wiat control W 10-13 Memory management R/W 00 Display memory start W
In Detail
Address = 00 Write only
start address of display memory
bit 7 A15
Address = 10..13 Read/Write
Memory management control
10 controls 0000-3FFF
Address = 20 Write only
Memory card wait state control
bit 7 = 1 for wait states, 0 for no wait
Address = 30 Write only
Baud rate etc.
bit 7 select card register 1=common, 0=attribute
Address = 40 Write only
Parallel interface data
The byte written here is latched into the parallel port output register. To
Address = 50..53 Write only
Sound channels period control
50 channel A period low
Address = 60 Write only
Interrupt request mask
bits 7-4 Not Used
Address = 70 Write only
Power off control
bits 7-1 Not Used
bit 0 1 = no effect, 0 = power off
Address = 90 Read/Write
IRQ status
bits 7-4 Not Used
Address = A0 Read only
Memory card/battery status
bit 7 Memory card present 0 = yes, 1 = no
Address = B0 - B9 Read only
Keyboard data
B0..B9 each key of the 64 on the keyboard
Address = C0 Read/Write
UART control/data
C0 UART data register
Address = D0 Read/Write
Real Time Clock chip (TM8521)
D0..DC Data
See data sheet of chip for more information.
NC100 operating system firmware
notes for external program writers
To get external programs executed on the Notepad you could either POKE
