Denial

Found this Vic-20 cartridge the other day. It's got a STACK label on the bottom, but I have no idea what it is or does.

All I know is that STACK had a bunch of utility cartridges, of which this is probably one of them.

Plugging it into my VIC-20 displays that the available BASIC RAM has increased to 6655 bytes (so it's probably a 3K expansion)... but aside from that I notice nothing different on power on.

Does anyone have any instructions or way of determining how it is used?

Some pictures of the cart.

I did some searching around for information on these carts.
I have at least determined that it is not Vickit 2.
http://www.nemetzpower.de/Denial/VICKIT-II.pdf

SYS 45056 does nothing.

My curiosity got the better of me, so I opened the cart shell.

There's no ROM in there. So it's only just a RAM expansion with a cart pass-through port?
Seems like a lot of chips for just 3K extra.

Looks a bit like the Stack Storeboard: http://www.computinghistory.org.uk/det/ ... toreboard/
...but obviously there's nowhere to add more RAM or add a ROM. It's just +3K and that's yer lot.

These RAM chips are the good old 2114's. They are 1024x4 bits. So, 6 of them are arranged on the board as 3072x8 bits.
(As you can deduce from the wiring pattern on the left in the second picture, where the datalines are divided 50/50 over the two rows of 3 chips).

These are used as base memory in many VIC-20s. In mine I have soldered six 2114s piggyback on existing ones on the motherboard (in 1984!).

Regards,

Wim.

I suppose RAM exapnsions aren't worth much, but I guess they have a use because they can be gutted for spare parts in case my VIC's memory blows.

RAM expansions no, but I've never seen that cart before, so it might be worth something. I'm guessing the pass through is so you can possibly run another 8k/16k on top, or another Stack utility cartridge.

According to https://archive.org/details/your-comput ... ne-1982-08 (pg 26) it looks to be a "Low Cost 3K Memory"

Does anyone have an idea, what that extra TTL on this cartridge is supposed to do?

Looks to be a NAND gate with the output connected to /WE of the RAMs. I can only trace one input, probably to the /VRW.

srowe wrote:According to https://archive.org/details/your-comput ... ne-1982-08 (pg 26) it looks to be a "Low Cost 3K Memory"

Interesting. So that solves this mystery!