The AWA RT85A is a later variant of the RT85, and comes in two
versions.
Unfortunately the RT85 and RT85A models are all marked as "RT85" on the
name plate, so it is neccesary to open the radio for identification.
The RT85C and Midland 70-530A are similar radios however the
following notes may not apply.
All versions are basically the same radio with different microprocessor
controllers.
The original RT85 has a mask programmed microprocessor mounted on the
main transmitter PCB. A small detachable daughter board contains
a EPROM and a
shift register chip and could be removed for programming in a
proprietary
Midland Programmers model 70-1000 and 70-1000C.
The RT85A version replaces the onboard microprocessor on the main PCB with a new micro mounted on a larger daughter board that plugs into the same connectors previously used for the EPROM board on the original RT85.
RT85A version 1:
The first variant of the RT85A processor board uses a 40-pin mask
programmed
Motorola 146805G2 microprocessor, with a 2k byte 2716 type EPROM and a
shift register chip. In this version the EPROM only stores
frequencies
and configuration data, and a few "library" functions. The main
program
code is stored internally in the microprocessor at the time of
manufacture and
is not readily accessible and cannot be changed.
The "Library" functions are used to extend the functionality of the
radio for specific applications that were not thought of at design
time. They
also allow some errors in the original program code to be overcome
without
having manufacture the very expensive masked ROM in the
microprocessor. These functions
are loaded in from the EPROM and executed at key points in the main
intenally masked ROM program whenever certain option bits at
EPROM addresses $03F6 & $03F7 are set.
This version of the radio can be identified by the small PCB mounted face up near the VCOs, and contains a 2716 EPROM, a 40-pin Motorola microprocessor chip, and a small logic chip.
RT85 version 2:
A later variant of the RT85A uses a 64-pin Hitachi HD6305Y2P
microprocessor, a 8k 2764 EPROM, and has no shift register chip.
The
EPROM in this model stores both the main program, as well as frequency
and configuration data, making the radio a lot more flexible in special
applications.
Channel and Configuration Data:
(Note '$' signifies hexadecimal values)The frequency (channel) data and the configuration (personality) data follow a nearly identical format in both the 2716 and 2764 EPROMs, except that this data is offset by an address of $1000 (hex 1000). The 2764 has the main program for the CPU stored in the EPROM below $1000. Whereas version 1 with the 2716 EPROM has "library" functions interspersed with this data, version 2 with the 2764 EPROM does not. Version 2 does not need to use "Library" functions since the main program can easily be modified in the EPROM.
The following table lists the function of each bit in the Personality Data:
*******************************************************
* Personality Data - AWA RT85A (RDNS versions)
* For MC6805 + 2716 EPROM version.
* EPROM $03F0 - $03FC
*
* Addresses for HD6305 + 2764 EPROM version are offset by $1000 and are
shown in brackets ( $nnnn ).
*
* NOTE: anything marked with '??' is questionable.
* Further advice requested. Send a message to vk3byy via the
Contact form at nerg.asn.au
*
$3F0 ($13F0)
nnnn nnnn
^^^^-^^^^--MAXCHAN FF ; Highest Channel number (01 to 99)
$03F1 ($13F1)
xxxx nnnn
^^^^--TXLIMIT 0F ; TX Timeout value
; 0=continuous, time(secs) = n*15
^-------DSPBLNK 10 ; Enable Display Blanking
after 20 seconds
^--------TXIBUSY 20 ; Enable Transmit Inhibit on BUSY
^---------TXIOPEN 40 ; Enable Transmit Inhibit on OPEN
^----------DPWRENB 80 ; Enable Hi/Lo output power link
; (Depower link) on back of control head
$03F2 ($13F2)
nnnx xxxx
^--SCANENB
01
; Enable Scanning
^---SCANTSQ 02
; Enable Scan Stop with CTCSS
^----SCANDEL 04 ; Enable
Chan DOWN key Deletes Scan Channel
^-----SCANHUR 08 ; Enable
Hangup up Resets Scan ????
^-------SCANPROG 10 ; Enable Self-Programming
Scan
^^^--------SCANHLD E0 ; Scan hold time ( 0 - 7 seconds)
$03F3 ($13F3)
xxxx xxxx
^--OPENHU
01
; Enable Silent switch
^---TSQENB
02
; Enable Tone Squelch (CTCSS on receive)
^----SELCENB 04 ; Enable
SELCALL
^-----STATENB 08 ; Enable
SELCALL Status call
^-------ANILEAD 10 ; Enable SELCALL
Leading
ANI
^--------ANITRAIL 20 ; Enable SELCALL Trailing ANI
^---------ANIBEEP 40 ; Enable Send ANI with beep
^----------CAR2CAR 80 ; Enable SELCALL Car to Car call
$03F4 ($13F4)
xxxx nnnn
^^^^--TIMER44 ; ANI SELCALL
lead-in time (1=short, 15,0=long)
^-------BSYDLY5 ; Enable Busy LED 5
second
delay
^--------SILSWEN ; Enable Silent switch ??
^---------SNDIBUSY ; Enable SEND Inhibit on BUSY
^----------SNDIOPEN ; Enable SEND Inhibit on OPEN
$03F5 ($13F5)
nnnn xxxx
^--VOTENB
; Enable Voting (if option fitted)
^---xxxx
; an option with timers, SELCALL, and beeps ??
^----SCANLED ; Enable
SCAN LED as Power Indicator
^-----OPENLED ; Enable OPEN
LED
^^^^-------TONEPER ; SELCALL tone period (0,F=slow,
E=fast)
$03F6 ($13F6)
xxxx xxxx
^--SCTXDEC
; Bypass TX code initialisation of SELCALL
^---xxxxxx
; unused (another CTCSS option in 2764 ver. ??)
^----F320
; Enable Lib 320 ?? (unused in 2764)
^-----F340
; Enable Lib 340 ?? (unused in 2764)
^-------xxxxxx ; Enable Lib 360
?? (unused in 2764)
^--------xxxxxx ; Enable Lib 380 ??
(unused
in 2764)
^---------xxxxxx ; Enable Lib 3A0 ?? (unused
in 2764)
^----------unused ; unused
$03F7 ($13F7)
xxxx xxxx
^--unused
; Enable Lib 680 ?? (unused in 2764)
^---unused
; Enable Lib 6C0 ?? (unused in 2764)
^----unused ;
Enable Lib 6E0 ?? (unused in 2764)
^-----ALARMRST ; Enable ALERT reset
enable via Depower/Hangup link
^-------unused ; Enable Lib 720
??
(unused in 2764)
^--------xxxx ; Enable Depower
link as DOWN key in user scan ??
^---------unused ; unused
^----------unused ; unused
* SELCALL ID - 5 digits, RX and TX digits combined into one byte.
* Transmit digits in highest 4 bits, Receive digits in lower 4
bits.
* Digits adjacent should not be the same (eg 24310 is OK, but 24430
is
illegal??)
$03F8 ($13F8-$13FC)
tttt rrrr ;1st digits TX & RX
tttt rrrr ;2nd digits
tttt rrrr ;3rd digits
tttt rrrr ;4th digits
tttt rrrr ;5th digits
--- end ---
Enable scanning by setting bits in
the personality data:
Turn on the scan option by setting bit 0 ($01) in byte $03F2.
Also set bit
2 ($04) if you want the "DOWN" button to skip over (delete) certain
busy channels . Up to 4 channels can be skipped (useful where
some repeaters suffer occasionally from LIPD interference for
instance). I
haven't figured out Self programming (user programming) options yet.
Scan Channels:
Enter the number of each channel to scan into a list starting at
address $0000 ($1000 for ver 2), with
each entry spaced 4 bytes apart. The list must end with a value
$FF. Note that the scan channel data runs contiguously through
the EPROM address space, unlike the channel data has a break between
channel
9 and 10, between 19 and 20, etc.. Channel numbers are
represented binary coded decimal, or in other words, as
two digits, the tens digit stored in the 4 high bits, and the ones in
the 4 low bits (as displayed
on the front panel, so channel 13 is entered as hexadecimal $13).
Channels can be in any order, and can include channel 0.
Channels
can occur more than once if you want to check them more often than the
others.
Example:
To scan channels 1,2,15,4,10,20,30,40,51,52,53,54,55,56,57,58,59 we
enter the following data at the addresses indicated: (note there is no
gap between addresses $0024 and $0030 - all are used).
Addr Data
$0000 01 ;first scan channel = ch 1
$0004 02 ;second scan channel= ch 2
$0008 15
; third scan channel = ch 15
$000C 04
; forth scan channel = ch 4
$0010 10 ;fifth = ch 10
$0014 20
; etc...
$0018 30
$001C 40
$0020 51
$0024 52
$0028 53
$002C 54
$0030 55
$0034 56
$0038 57
$003C 58
$0040 59
$0044 FF ;end of scan list
$004C FF, etc....
--- end ---
RT85FAQ