Argus 3000/5000/7000 (Monochrome) Hacking – 1

The system design of these moving map displays is surprisingly compact. It is a streamlined 68000 system with a CRT display. It reminded me of those early Z80 computers.

Version 5.0 has a different PCB design. But I believe the only major change is in the ROM section.

Python Script to interleave the two halves of the ROM dump

import itertools
f1 = open('ARGUS7000_3.2_U2.bin','rb');
f2 = open('ARGUS7000_3.2_U3.bin','rb');
fout = open('ARGUS7000_3.2.bin','wb+');
b1 = f1.read();
b2 = f2.read();
f1.close();
f2.close();
fout.write(bytearray(itertools.chain(*zip(b1, b2))))
fout.close();

Unfortunately, all pages of the ROM are copyrighted, I can’t offer a download link of them.

Memory Map:

Processor A[23:21]	R/W	CEn generated
3’b000 ($0xxxxx)	R	System ROM
3’b001 ($2xxxxx)	R	244 (Keyboard/Cassette Input Latch)
3’b010 ($4xxxxx)	R	External ROM (Map Data)
3’b011 ($6xxxxx)	RW ?	ADC
3’b100 ($8xxxxx)	RW	68681 (RS232, GPIO)
3’b101 ($Axxxxx)	RW ?	6845 (CRTC)
3’b110 ?	?	Unknown
3’b111 ($Fxxxxx)	RW	DRAM

ADC and 6845 are supposed to be read-only, but for some reason, the decoder PAL doesn’t care.

With the memory map acquired, the ROM can be disassembled like a generic 68k system. There doesn’t seem to be any unusual design.

Some Disassembly (Version 3.2)

RS232 Terminal Mode (Firmware Version 5.0+)

Starting from firmware 5.0, the Argus maps all have a special mode built-in that allows the device to operate as a terminal. To enter this mode, do the following:

1. Hold ENR & AUX keys during power-on, until you see “SETUP MODE ENABLED” during boot-up
2. Tripple click “AUX” to enter the setup menu
3. In the “LRN TYPE SELECTION” page, select “ASCII Port A” (Transmit ASCII) or “HEX Port A” (Transmit ASCII encoded hex)
4. Click “PAGE” until you see “DATA FORMAT SELECT”, configure the RS-232 parameters as you want. (Note: Argus doesn’t support hardware handshaking. It only supports XON/XOFF)

Now the device is ready for receiving. The following escape sequences are available:

ESC Sequence	Function
<ESC>[1?	Report the model number
<ESC>[2?	Report the serial number
<ESC>[3?	Report software version
<ESC>[4?	Report cursor position
<ESC>[5?	Report CRT brightness (CE only)
<ESC>[NA	Move the cursor up “N” lines
<ESC>[NB	Move the cursor down “N” lines
<ESC>[NC	Move the cursor right “N” characters
<ESC>[ND	Move the cursor left “N” characters
<ESC>[Y;XH	Move the cursor to character row “Y” col “X”
<ESC>[J	Clear screen and cursor position
<ESC>[K	Erase from the cursor position to the end of the line
<ESC>[m	All character attributes off, set to “monospace” font. Set color to yellow, Set repeat rate to 1pps
<ESC>[7m	Set reverse video on all following characters
<ESC>[31m	Set foreground color to red
<ESC>[32m	Set foreground color to green
<ESC>[33m	Set foreground color to yellow
<ESC>[s	Save cursor position
<ESC>[u	Restore cursor position
<ESC>[10m	Set to “small” font
<ESC>[11m	Set to “medium” font
<ESC>[12m	Set to “large” font
<ESC>[13m	Set to “monospace” font
<ESC>[14m	Set to “giant” font
<ESC>[BBh	Set CRT brightness to “BB” (CE only)
<ESC>[TTi	Set repetition rate to “TT”*20ms
<ESC>[5Nm	Draw to screen “N”, N=0~3
<ESC>[6Nm	Copy screen “N+1” to “N”, N=0~2
<ESC>[77m	Manual brightness adjust mode (CE only)
<ESC>[78m	Software brightness adjust mode (CE only)
<ESC>[70m	Drawing mode “OR”
<ESC>[72m	Drawing mode “XOR”
<ESC>[PPPPPPPPb	Set drawing pattern to “PPPPPPPP” ( The feature seems to be broken)
<ESC>[73m	Drawing mode “Pattern MOVE”
<ESC>[74m	Drawing mode “Pattern OR”
<ESC>[76m	Drawing mode “Pattern XOR”
<ESC>[Y;Xa	Set cursor to “X,Y”
<ESC>[Y;Xc	Draw a line from cursor to “X,Y”
<ESC>[S;E;Rd	Draw an arc centered at the cursor, with starting angle “S”, ending angle “E”, radius “R”
<ESC>[Y;Xe	Draw a filled box from cursor to “X,Y”
<ESC>[Y;Xf	Draw a outlined box from cursor to “X,Y”
<ESC>[80m	Disable scrolling
<ESC>[79m	Enable scrolling
<ESC>[YLL;XLL;YUR;XURg	Set clipping limits, default value: YLL=488, XLL=1; YUR=1; XUR=256
<ESC>[81m	Set character height to one line
<ESC>[82m	Set character height to the minimum of the current font

1. This is an paraphrase from the Argus Reference Manual
2. The screen pixels are not square, they are 2:3. This will affect how an arc is drawn

Some test code to plot that Sanae-san image

import serial
import time

from PIL import Image
import matplotlib.pyplot as plt
import numpy as np
simg = Image.open('Th12Sanae_bw.png')
plt.imshow(simg)
simg_b = np.array(simg.convert("1"))


ser = serial.Serial('COM5',38400)
print(ser.name)
ser.write('\x1b[J'.encode('ANSI'))
ser.write('\x1b[11m'.encode('ANSI'))
ser.write('\x1b[50m'.encode('ANSI'))

#ser.write('\x1b[256;128a'.encode('ANSI'))
ser.write('\x1b[J'.encode('ANSI'))
ser.write('\x1b[70m'.encode('ANSI'))
ser.write(('\x1b['+str(0xF)+'b').encode('ANSI'))

for i in range(256):
    s = simg_b[:,i]
    sl = False
    p = 0
    pl = 0
    for c in s:
        p = p+1
        if(sl!=c):
            if(c==False):
                ser.write(('\x1b['+str(pl)+';'+str(i)+'a').encode('ANSI'))
                ser.write(('\x1b['+str(p-1)+';'+str(i)+'c').encode('ANSI'))
            sl = c
            pl = p

ser.close()

VRAM Address

CPU Addr Bus (S=00)	CPU Addr Bus (S=01)	CRTC Addr (S=10)	CRTC Addr (S=11)	DRAM Addr (Y)
A8	A9	RA2	MA5	A0
A7	A16	RA1	MA12	A1
A6	A15	RA0	MA11	A2
A5	A14	MA4	MA10	A3
A4	A13	MA3	MA9	A7
A3	A12	MA2	MA8	A4
A2	A11	MA1	MA7	A5
A1	A10	MA0	MA6	A6

The DRAMs, as you’d expect, are addressed in the “CAS/RAS” way: Their 16-bits of total address width is issued twice by the DRAM PAL controlled MUX. The total DQ bit width is 16bits. (hence no A0 from the CPU)

Screen’s Horizontal Lines – CRTC’s Vertical: 512 bits in total, Shift Register contains [15:0] = 16 bits, the rest is addressed by MA[4:0]

Screen’s Vertical Lines – CRTC’s Horizontal: 256 scanlines in total, addressed by {MA[9:5],RA[2:0]} (probably, not verified).

Paging is probably controlled by MA[12:10] by modifying the R12 – Starting High Address Register

DRAM Controller PAL

The DRAM addressing and refreshing is controlled by a single PAL chip. This is quite an elegant design considering how limited the PALs were at that time. The PAL is encrypted, so I can’t read the content easily with my TL866. But here’s something very close.

This National Semi DP84322 DRAM controller chip seems to be a relabeled PAL. The Argus implementation added 3bit high address decoding and MUX control logic on top of this.