What is FRAM?

FRAM acts pretty much exactly the same as standard 62256 SRAM we all use in our TEC-1G, except inside it has tiny ferrite donuts that get charge with a magnetic polarity depending on whether you're writing a 1 or a 0 to that cell. When the power goes off, the magnetic polarity hangs around, similar to how a VHS tape holds onto the information on it. When you power back up, all your program is exactly where it was when you turned your machine off.

The RAMTRON 32K FRAM chip used to be available in 28pin DIP configuration (I actually own two if them!) but were discontinued a long time ago and are now rarer than Dodo Birds. But the SOIC (surface mount) version of them is still readily available. So all that needed doing is making a carrier which is what we have here.

How to Use the 32k FRAM - A simple Plug & Play

The TEC-1G has two 28 pin sockets that can take this FRAM module. In the left slot, the FRAM becomes your main system memory, starting from $0000 and goes up to $7FFF, making up 32K that never loses its contents! In the right (Expand) socket, you have access to 32K by way of two 16K windows. Controlling which window the TEC-1G "sees" is done with the Fn-E shortcut when in the Monitor, or using the "Toggle Expand" in the main menu. I use this to backup any programs I have in main memory and then flick the EXPAND off, to "hide" that portion of FRAM from the machine, so it cannot get corrupted by any rogue program.

For the EXPAND socket, just make sure you have the "chip size" jumpers set correctly to be able to work with 28pin chips, and set to "other" on the switches. If you're using this in the main 32K RAM socket, nothing needs be done but ensure you install the FRAM in the correct orientation, pin 1 being bottom right.

Kit Options

As with my other kits, you can buy just the PCB, all the parts but unassembled (although doing surface mount soldering can be a little challenging if you don't have the right equipment), or you can buy the parts partially assembled (needing you to solder the DIP pins in) or fully assembled. Only the assembled versions will be tested, and no warranty can be given on the separate components parts, as soldering surface mount is tricky and prone to damage and bad soldering. For partially assembled, I will do a continuity test between the pins of the FRAM chip and the pin holes, ensuring no shorts as well. The fully assembled unit will be fully tested in my actual TEC-1G and some data written to it and read back to ensure full operation.

Please note that this FRAM can be used with some RC2014 / RCBus systems, some Microbee machines, and any retro computer that can use a standard 62256 SRAM, as it is pin- and timing-compatible.

NOTE: The first version of this board (green) was printed upside down when you have them actually plugged into a TEC-1G. I didn't realise the error until after I made my first batch of this completed units. So if you purchase the assembled versions, I have 3 units in green that will sell first - making them super rare collectibles! (Am I selling you on it? ;) Anyone buying just the PCB or the separate components will have the White version of the PCB.