The AWA RT85A is a later variant of the RT85, and comes in two versions.
They are basically the same radio except for the microprocessor daughter
board.
The original RT85 had a mask programmed microprocessor mounted on the
main transmitter PCB. A small detachable daughter board contained
an EPROM and a
shift register chip and could be removed for programming in a proprietary
Midland Programmer.
The RT85A version removed the microprocessor from the main PCB and mounted it on a larger daughter board which plugs into the connectors previously used for the EPROM board on the RT85.
One 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 program
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 would either not fit into the 6805
CPU's limited mask memory, or were not thought of at the time. They
also allow some errors in the original program code to be overcome without
having to manufacture a few thousand new microprocessors. These functions
are called at key points in the Mask ROM program provided option bits at
EPROM address $03F6 & $03F7 are set.
A later variant of the RT85A (A+ ???) uses a 64-pin Hitachi HD6305Y2P microprocessor, a 8k 2764 EPROM, and no shift register chip. The EPROM in this model stores both the main program, as well as frequency and configuration data.
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 2716 also has "library" functions interspersed with this data. The 2764 does not. The 2764 has the main program for the CPU stored in the EPROM below $1000. The HD6305/2764 version does not need to use "Library" functions as the 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 shown in brackets().
*
* NOTE: anything marked with '??' is questionable.
* Further advice requested. Send to [email protected]
*
$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, and bit
2 ($04) if you want the "DOWN" button to delete up to 4 channels in the
list (the repeaters suffering LIPD interference for instance). I
haven't figured out Self programming (user programming) options yet.
Enter scan channels into a list starting at address $0000 ($1000) with entries every 4 bytes. The list ends with a value $FF. These locations correspond to the first byte of each channel's receive data. Note however that the channel data has a break between channel 9 and 10, 19 and 20, etc, etc whereas the scan channel runs sequentially without gaps in the memory map. Channel numbers are represented as two digits, one in the 4 high bits, the other 4 low bits (as displayed on the front panel - not as a binary number).
Channels can be in any order, and can include channel 0. Channels can occur more than once.
Example:
To scan channels 1,2,3,4,10,20,30,40,51,52,53,54,55,56,57,58,59 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 = ch 2
$0008 03
$000C 04
$0010 10 ;fifth = ch 10
$0014 20
$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