I managed to get the 5×2 pin header, and a “jtag cable” from a previous employer. I haven't soldered in awhile so I messed with it awhile trying to desolder all the points to attach the 10-pin header. Well, turns out, as far as I know, that the ground connections are not drilled through. So I attached ground to the serial port. Then I look at the “jtag cable”. It's not wired at all like any JTAG I saw mentioned. Well, Bob did say he tried to make his own once and it didn't work. I guess that's the one he gave me. Don't know why, he's got several. One is USB, wish I borrowed that one now..

So I re-wire the jtag cable to use the “DLC5” aka “very poor man's jtag” pin-out. There are resistors on our PCB which should be plenty, but I added what I had and they're like 450ohm and seem to work… Then, software… tjtag would be awesome if it worked. It doesn't seem to use DLC5 correctly for me…? Then I noticed I need nTRST at 3.3v, so I tied that to the serial port as well. so our 14-pin JTAG has pin1 going straight to 3.3v (shoulda used a 100ohm resistor they say), and next 4 pins down the left side going to parallel port pins 2,13,4,3 (in that order) and parallel port's ground going to serial port ground…

For visual: diagram mine

So I tried tjtag again and no dice. wtf. but some italian program for AR7 noticed the CPU ID as “1” so I searched and found UrJTAG. I had to find libusb0.dll and ftd25xx.dll so the program will run. Neither library being utilized… wtf! But works better than getting cygwin for the old jtag tools ports.. What a day! All to save a $15 router. hah.

I returned from sleep and it didn't work. I programmed the wrong address. soooo unless UrJtag says the Manufacturer and Chip type, it's not gonna work. Remember that. I assumed it was a supported family, but unsupported chip and thus didn't display. 0x3fc00000 would be the 16-bit access to any MIPS CPU's boot-rom, which is of course mapped to flash for us. It's also mapped at 0x30000000. For me, the 64k image takes just under 30minutes to flash. I recommend using noverify when flashing.

C:\Program Files\UrJTAG>jtag.exe

UrJTAG 0.10 #1502
Copyright (C) 2002, 2003 ETC s.r.o.
Copyright (C) 2007, 2008, 2009 Kolja Waschk and the respective authors

UrJTAG is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
There is absolutely no warranty for UrJTAG.

WARNING: UrJTAG may damage your hardware!
Type "quit" to exit, "help" for help.

jtag> cable dlc5 parallel 0x378
Initializing parallel port at 0x378
jtag> detect
IR length: 5
Chain length: 1
Device Id: 00000000000000000000000000000001 (0x0000000000000001)
  Unknown manufacturer!
chain.c(149) Part 0 without active instruction
chain.c(200) Part 0 without active instruction
chain.c(149) Part 0 without active instruction
jtag> include admtek/adm5120/adm5120
ImpCode=01000001010000000100000000000000 41404000
EJTAG version: 2.6
EJTAG Implementation flags: R4k DINTsup ASID_8 NoDMA MIPS32
Processor entered Debug Mode.
jtag> detectflash 0x3fc00000
Query identification string:
        Primary Algorithm Command Set and Control Interface ID Code: 0x0002 (AMD/Fujitsu Standard Command Set)
        Alternate Algorithm Command Set and Control Interface ID Code: 0x0000 (null)
Query system interface information:
        Vcc Logic Supply Minimum Write/Erase or Write voltage: 2700 mV
        Vcc Logic Supply Maximum Write/Erase or Write voltage: 3600 mV
        Vpp [Programming] Supply Minimum Write/Erase voltage: 0 mV
        Vpp [Programming] Supply Maximum Write/Erase voltage: 0 mV
        Typical timeout per single byte/word program: 16 us
        Typical timeout for maximum-size multi-byte program: 0 us
        Typical timeout per individual block erase: 1024 ms
        Typical timeout for full chip erase: 0 ms
        Maximum timeout for byte/word program: 512 us
        Maximum timeout for multi-byte program: 0 us
        Maximum timeout per individual block erase: 16384 ms
        Maximum timeout for chip erase: 0 ms
Device geometry definition:
        Device Size: 8388608 B (8192 KiB, 8 MiB)
        Flash Device Interface Code description: 0x0002 (x8/x16)
        Maximum number of bytes in multi-byte program: 1
        Number of Erase Block Regions within device: 2
        Erase Block Region Information:
                Region 0:
                        Erase Block Size: 8192 B (8 KiB)
                        Number of Erase Blocks: 8
                Region 1:
                        Erase Block Size: 65536 B (64 KiB)
                        Number of Erase Blocks: 127
Primary Vendor-Specific Extended Query:
        Major version number: 1
        Minor version number: 1
        Address Sensitive Unlock: Required
        Erase Suspend: Read/write
        Sector Protect: 4 sectors per group
        Sector Temporary Unprotect: Not supported
        Sector Protect/Unprotect Scheme: 29BDS640 mode (Software Command Locking)
        Simultaneous Operation: Not supported
        Burst Mode Type: Supported
        Page Mode Type: Not supported
        ACC (Acceleration) Supply Minimum: 11500 mV
        ACC (Acceleration) Supply Maximum: 12500 mV
        Top/Bottom Sector Flag: Bottom boot device
jtag> flashmem 0x3fc00000 u-boot.img noverify
Chip: AMD Flash
        Manufacturer: Macronix
        Chip: MX29LV640B
        Protected: 0000
program:
flash_unlock_block 0x3FC00000 IGNORE

block 0 unlocked
flash_erase_block 0x3FC00000
flash_erase_block 0x3FC00000 DONE
erasing block 0: 0
addr: 0x3FC01000