Update: Programming the RAMTRON FerroMagnetic FM16w08 chips for my Tektronix 2465A scope with the brandnew TL866II is simply impossible! Although they are supported in the device list the universal programmer sadly kept giving at least 24 verify errors. And also a second brandnew FM16w08 failed in the same way!
Luckily my RT809H was completely capable to program, read and verify both memory chips perfectly! But only after I upgraded the windows program to new version 20210222. Because previous RT809H version only supported the FM1808 type for my 2440 Tek scope.

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Warning! Although the 62256 SRAMS in the Tek 2440 scope look exactly easy IN-CIRCUIT READABLE as the 4464 SRAM does that also is only connected to the Backup Keeper Lithium Battery in the 2465A scope if the scope is powered off (meaning no data- or addressbus conflict!). However reading the calibration data from the Tek 2440 SRAM chip completely failed verify wise. I made a special 28 pins 27c256 eprom to 28 pins 62256 testclip reader cable and attached it to my TL866II and after that also with my G540 universal programmer. But both failed to read the data without any read error! And afterwards I needed to SELF CALIBRATE the 2440 like explained in this repair article. But I again was able to PASS all previous scope errors that occur when the NVRAM or the calibration in it was corrupted. Which now still only leaves the External Calibration (Ext Cal) procedure that is at fault and just requires removing a jumper on the scope's mainboard and manually calibrate the scope's inputs by providing a few good calibrated signals to setup the internal CCD memory and adjust the amplifier values in NVRAM.

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PS: there is no need to remove any of the databuffer chips or the CPU to be able to read the data in the 4464 SRAM because if the scope is powered off there is no address or databus line conflict since at that moment the Sram will be the only functioning component in the 2465A (or the 2440 or other equally designed Tektronix) scope!

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Update: The Tektronix 2440 SRAMS are HM62256 32KB type rams that require the special FM1808-70-PG ferro magnetic memory chips instead the FM16w08 (or the FM1608 DIP) that have 4 times more memory capacity compared to the original DS1230 32K chips often used in the 2440 memory oscilloscope. I was able to buy 2 FM1808s DIP on eBay for only US$5.89 (about 4,95 Euro). And they have a worry free retention time of 10 years without the need of any dangerous lithium backup battery. That also can leak in time! The above mentioned testclip with 28 pins socket cable can still be used after pin 26 is reattached to the testclip and its 100 ohm pullup is removed because it here is addressline A13 instead of the CE pin it was on the 4464 SRAM.

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Thanks Humberto. I just fixed some new repairs.

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By-the-way: I also do have a original Hameg HZ65 Component tester that works similar like the Huntron Testdevice you mentioned. But the thing with these kind of testers is that you likely do need to compare the curve of a presumably Bad Semiconductor with the one of a second Semiconductor V/i curve that you know is still 100% OKAY. So you probably never can be very sure when you test on a Bad working Device. Because the Testcables also influence the way how the Scopecurve is displayed.

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