3-Feb-11

	I think anyone who owns a Unisite needs to breathe a silent 'Thanks!' for whatever 'mystery tech' created the file in this archive. I have no idea who sent it to me -- It simply appeared in my FTP site's upload folder a few days ago, with the exact file name you see in the archive, along with an entirely anonymous note saying only "You're welcome. Share it!!"

	When something this significant comes along, I'm not inclined to question it. So, I will honor whoever put the hard work into this by doing exactly that - sharing it!

	What is it, you ask? It's the breakdown of the 22V10 PLD, in the U91 position on the Unisite's main board, which upgrades the programmer to use 8MB RAM.

	To use this material, you must have the following:

	--A Unisite programmer with controller board P/N of 701-2313-xxx. This board is easily distinguished from earlier boards by the presence of two 30-pin memory SIMM sockets in the lower left quadrant.

	--A blank 22V10-class SPLD. These are still available from Atmel and other chip makers, but don't use anything rated slower than 25nS.

	--A programmer to handle the above chip (duh!)

	--A sense of adventure.

	If you're using another Data I/O programmer to create the 22V10, you will need to transfer the JED file under their format #92 (JEDEC Kernel). The checksum should be 0x93DC. Other programmers, such as Advin, BPMicro, Needham, etc., should have no trouble with the file as it is in standard JEDEC format. Worst case, you can use the source .PLD file to compile something you can use.

	For those who may not know the past history: Unisite programmers with controller board P/N 701-2313 are normally equipped with a 22V10 PLD, Data I/O part #324-1852-003, in the U91 position. This device determines how much memory the Unisite will see. Even if you plug in a pair of 4MB SIMMs, the programmer will never see the extra memory as long as this PLD is installed.

	Unisites which have the 8MB option have a similar PLD, DIO P/N 324-1852-002, in the U91 position. This device 'unlocks' the extra memory. Past attempts to discover the nature of its contents have been unsuccessful, due to the PLD's security fuse being blown when it was initially programmed by DIO.

	Now, it appears someone has managed to reverse-engineer the functionality. Darned if I know how they did it, but I'm bloody grateful! This is a mystery which has persisted since the Unisites went through their first hardware update around 1990.

	This mysterious gift was nothing if not complete. It included the PLD source file as well, and it even has the pin labels matching the controller board schematic designations. Whew!!

	So, off it goes into the world.	Enjoy!