Upgrade Hacking - 1M 2M options - TDS500 TDS700 - Series C or D

[Tantratron]

Hello, as it is known and experiment by different members, it is quite easy to upgrade via GPIB the SRAM acquisition A10 board from 1M or 2M options. Some of these A10 boards have already soldered the maximum SRAM storage memory so only by software we can manipulate or set which option: 50Ko standard or 500Ko (option 1M) or 8 Mo (option 2M).

However after inspecting 6 different TDSxxx wether C serie or D serie, I have two technical questions.

First here are the different SRAM models I've found so far within the TDS520D, TDS540C, TDS754D, TDS784C and TDS794D:

• AS7C164 (8K x 8bits) able to offer option 1M
• AS7C256 (32K x 8bits) but the two TDSxxx were set standard 50K
• IDT7124 (128K x 8 bits) able to offer option 2M

Question 1: do you know if the oscilloscope will fail or brick or self-detect an issue when forcing option 2M (8Mo) but the SRAM total memory is able only to offer 50Ko or 500Ko storage

Question 2: what is so particular with AS7C256 because I find strange the total memory (there are always 16 SRAMs per channel) offers 32K*16*4 = 2Mo

Does this AS7C256 internal mapping hardware can only work with 50Ko option even though its storage is higher or is it OK to set at 500K (option 1M) without failure ?

Thanks, Albert

[madao]

I have  repaired many TDS700/500.

only old TDS540/520 has 8x 6116 SRAM per channel, if 1M option is ordered ->  upgraded to  6264, swapping to 6264 is possible. (but CPU board must be also upgraded to  1M (few 62256 to 621024 swapped)
TDS744/724A/754C has  8x 6264, indepent of 1M Option, it is up to 1M hackable. 2M Option requiered other acquisition board(swapping to bigger SRAM is not possible)
TDS754D with old ACQusition has 16x IDT 71024 SRAM (128k x8), up to 2M hackable.
TDS754D with new ACqusition has 8x MT58LC128K32  (128k x32 )  dito up to 2M.

Greetings
matt