Reverse engineering Tektronix TDS3GV module for TDS3000 series oscilloscopes?

[stas_last]

slightly modified for esp32. Now works on web sockets. made a save button.

I attach the archive.

[YuukiJapanTech]

Hi.
I have the TDS3GM, which has no VGA output compared to the TDS3GV, but the other features are similar.

I disconnected the connector to check the pattern of the logic IC.
All patterns from the connector to the logic IC are visualized, so please refer to them.

TDS3GM was also a 4-layer board, but when it was transmitted by a very strong light, the second and third layers had only VCC and GND.

I also wrote pin assignments on the photos I analyzed for VGA, etc. Thank you for the analysis!
I think the VGA DA converter IC use ADV7120, can probably other use  BU3616K.

I would like to complete a board that fully supports TDS3GV someday, so I'll do my best to analyze it...

[pschirrer]

Hello,

I have a TDS3014 and just connected the Serial cable using a USB FTDI TTL to USB adapter, like described earlier in this post.
The scope is receiving the characters I type (checked using the debug feature of the RS232 menu). The scope is sending data when performing a screen dump through RS232, but it is not responding to commands sent to the RS232 port (*IDN? command for example). I can see it received it (debug menu), there is no error reported, but no characters are sent (0 sent in the debug menu).

Anybody know what is happening ? How can I get the scope accept commands ? I would like to offload the channel data to do some post analysis.

Thanks.

[pmercier]

You will have to downgrade your firmware to 3.39. With the newest version I don't get an answer too event if the debug see the communication (except for the print screen).

[pmercier]

@YuukiJapanTech Here what i have reversed from reverse engineering the schematic from different photos (maching yours too)

Screen
2 DotClk (25Mhz)
3 HSync (31.5KHz)
4 VSync (60Hz)
6, 7, 8, 9 Red
51, 52, 54, 55 Green
56, 57, 59, 60 Blue

Ethernet (SNI)
15 Tx
16 Rx
17 TENA
18 CLSN
19 RENA
20 TCLK
22 RCLK

Adrs
37 A11
39 A10
40 A9
41 A8
42 A7
43 A6
44 A5
46 A4
47 A3
48 A2
49 A1
50 A0

Data
82 D0
83 D1
84 D2
85 D3
87 D4
88 D5
89 D6
90 D7
92 D15
93 D14
94 D13
95 D12
97 D11
98 D10
99 D9
100 D8

Ctrl
22 /INT
24 CARD_INSERTED (5K to ground for 3GM)
81 R/W

Power
12 3v3
72 5v

Grounds 1, 5, 10, 21, 32, 38, 45, 53, 58, 67, 80, 86, 91 and 96

Serial (from james_s) :
68 TxD
69 RxD
70 RTS
71 CTS

They are the ones i have written in my notebook, but i've more on the reverse schematic (don't remember the one i reversed). I'll have access to it once am back to home tonight.

Edit:

D0 to D7 was flipped, they now have the good pinout
I've 8 more pins, but as i still haven't finished the reverse, i don't know was they are exactly. They are control signals for the card, but don't know for the moment what they are doing.

[pschirrer]

Hello pmercier,

Sorry, I forgot to mention that the scope reports version 3.39...

So what should I do ?

[pmercier]

Do you have all options activated ?

[pschirrer]

Hello pmercier,
I guess so, I have updated one of the modules to "TDS3ENG" and they show all activated.

Regards

[pmercier]

Strange. Look like i have this problem with my 3K model A too with the latest firmware version. I cant downgrade for the moment as I have no more floppy drive

[pmercier]

My bad. Look like I made a mistake in one of my previous response. I had no problems getting the IDN response on my model C, but not on my model A.

[buffdriver]

Hi,

This is my first post.  I've bought a TDS3012 and while awaiting delivery, I'm reading up on both the bandwidth and module hacks.  Since I won't have access to a communication module, I am interested in getting serial access via this solution.

The scope is sending data when performing a screen dump through RS232, but it is not responding to commands sent to the RS232 port (*IDN? command for example). I can see it received it (debug menu), there is no error reported, but no characters are sent (0 sent in the debug menu).

I had no problems getting the IDN response on my model C, but not on my model A.

I've read through the thread several times, but I'm not sure of the current status for non-B or -C units.  Has anyone had success with getting one of these earlier scopes to respond to serial commands?

Thanks,

buffdriver

[pmercier]

I have a -A and a -C. I was able to send serial command to the C version and it responded. But due to a TOO recent firmware on the A it won't answer any command at all.

[av500]

24 CARD_INSERTED (5K to ground for 3GM)

same for TDS3GV which I bought just before you posted that 5K to GND value which probably is enough to fake it :/

[james_s]

Strange. Look like i have this problem with my 3K model A too with the latest firmware version. I cant downgrade for the moment as I have no more floppy drive

Isn't it just a standard PC slim floppy drive? Looks like they can be bought for a few dollars, seems like it's worth having one around if only for the ability to update the firmware.

[Galen]

The drive is a slim type standard floppy drive. Not a specialized part for Tek.

[pmercier]

@james_c : I've a lot of floppy drives, but all of them avec missing something : real usable floppies ... So i've buyed a slim floppy emulator for my 3000A but i haven't been able to make it work. Need to test it again with a normal floppy emulator (and make a slim to HE34 adaptator ...)

@av500 : No it's not enough to make the scope accept a "virtual" extension card. I've already confirmed that

[Galen]

for the video signal, the ADV7120 has 8 bit input for each color, but based on pmercier's pin list, the scope only has 4 bit for each color? is this correct?

[pmercier]

The scope provide only 4bits per colour on the connector. Checked directly on the mother board.

[Galen]

The scope provide only 4bits per colour on the connector. Checked directly on the mother board.

Thanks pmercier, very helpful pin list.
Then, for each color, are the rest 4 bit pins of ADV7120 grounded or pulled up to 5V?

[james_s]

I've used the ADV7123 in other things before, the datasheet says to ground unused inputs. If you tie them high you'll never be able to display black.

[Galen]

I've used the ADV7123 in other things before, the datasheet says to ground unused inputs. If you tie them high you'll never be able to display black.

Thanks James_s.  I ordered a few ADV7120 and 74LCX245. But the connector is not cheap.  I may try to use a PCB with finger contacts for the test first.

[Jwalling]

The drive is a slim type standard floppy drive. Not a specialized part for Tek.

Not always true, earlier ones had a wider drive, but otherwise standard interface. The wider drives were also used on some of the TDS500 to TDS700 scopes as well. Because of this, there are two different rear covers to accommodate the different size drives.

[madao]

wider slim floppy is not  a tek special. it is using also in HP oscilloscope and some notebook (very old)
Wider slim floppy drive is  excatly wide as  3.5" standard  FDD.


Thanks for reserve engineering of   TDS3GM /GV Module.

Greetings
matt

[james_s]

Thanks James_s.  I ordered a few ADV7120 and 74LCX245. But the connector is not cheap.  I may try to use a PCB with finger contacts for the test first.

Isn't the connector only about $10? It would be expensive if you needed a bunch of them but for just one that doesn't seem too bad to me.

[Galen]

Yes James, found another source, price only 3 bucks each. Ordered 3 pieces.