开云体育

Details here have been worked out by members of the group. The data is incomplete, and of course may contain errors. 开云体育's table formatting is abysmal; anyone have a fix?

Memory Map

Overview

Range	Contents
0000-0027	MPU control registers
0028-003F	Nothing
0040-013F	MPU on-board RAM
0140-3FFF	Nothing
4000-4007	Synthesizer registers, latch U503 (usually written thrice: once with desired bit pattern, then again with A3=STROBE, then again without A3) [write only]
4008-7FFF	Nothing
8000-BFFF	Code plug (observed: 2k: -87FF, 8k: -9FFF; presumably a 16k would be -BFFF)
C000	Write: Audio Control Bus, latch U504
C000-CFFF	Read: Firmware EPROM

RAM details

Offset	Contents
0040-0041	"Memory initialized" signature: 0xA55A
0043	Current mode number (why two copies? cf 0077)
0077	Current mode number (why two copies? cf 0043)
00A0	Status byte of some sort; 0x8_ error codes get set here
00A1-00A2	Memory location of current mode entry, calculated from value at 0077
00A3-00A4	Memory location of current mode entry, calculated from value at 0043
013F growing down	Stack

I/O Details

Synthesizer program locations

(get from Arduino code)

Audio control bus bitmap

Bit	Function
0	Option RX through de-emphasis filter (inverted at switch)
1	Option RX flat (inverted)
2	Option TX through splatter filter (inverted)
3	Option TX flat
4	(Audio?) Preamp /WE (active low)
5	Squelch LSB (controls Q203)
6	Squelch MSB (controls Q202)
7	Mic Mute (inverted)

Code Plug

Header

Offset	Contents
0000-0001	Offset of last byte in plug (observed: 2k: 07FF, 8k: 1FFF; presumably a 16k would be -3FFF)
0002-0003	Simple 16 bit checksum of plug contents of 16 bit words from 0004-end
0008	Highest valid mode number (observed: 0x20 in 2k, 0x40 in 8k; would a 16k be 0x80?)
001A	Initial mode to select at coldstart; if 0, radio uses 1
0100-	Mode entries
????-	PL and other data pointed to by mode entries

Mode Entry

Offset	Contents
00-02	RX synthesizer programming bits
03-05	TX synthesizer programming bits
06	Something PL-related
17	Last byte