What's this? [Ebay]

[orion70]

I have found this auction for a "GS Vic Cartridge simulator", whatever this means. Seems to be battery powered, and has empty chip sockets. Someone knows more?

Auctioneer says

If you need one of these you will know what it is...

If you have no idea then you dont need it .

i.e., I really don't know what the heck this is

[srowe]

It's made by Audio Computers, it was advertised as 8K RAM plus 3 slots. I think it's been heavily modded.

[Mike]

It's the same VCS VIC Cartridge Simulator as has been discussed a few years ago. This time, without cartridge shell and with a variant assembly of edge connectors.

If you look closely in the *bay photos, the "V" hides under the left (mostly) open socket, and the "G" of "GS" is actually a C.

[srowe]

OK, I've now received this cartridge. The jumper block has been modified but tracing the circuit I've worked out that it allows

• selecting the socket BLK5 line between BLK5 and BLK1
• enabling the onboard 8K between BLK1 and BLK5
• write protect

unfortunately it repeats the error on other Audio Computers cartridges of using CR/W rather than VR/W.

[Vic20-Ian]

Once you get it working please can you post a guide on how to use it?

[srowe]

Once you get it working please can you post a guide on how to use it?

Will do, I need to check the documentation that came with my 16K RAM cartridge in case there's any details in that. I've got some RAM chips on order for it.

[Noizer]

(...) unfortunately it repeats the error on other Audio Computers cartridges of using CR/W rather than VR/W.

What does the error do?

[srowe]

Mike's previous explanation

http://sleepingelephant.com/~sleeping/i ... 192#p78037

I'm still not clear, given that external RAM is only enabled by BLK/RAM lines, if using the wrong R/W line can cause actual problems.

[srowe]

OK, so I've found my original documentation and this is what it says about the VCS

The cartridge simulator fulfills the needs for back plane expansion
for the intensive user who wishes to add more peripheral devices to
the Vic, with the possibility of more memory.

First of all, the VCS offers either just three 22 way slots, or three
slots in addition to 8K of Ram. The Ram used are identical to those
used in the VCR cartridge. The VCS can therefore be added to the basic
Vic, providing 11775 bytes free if you have the 8K version. You can
also use it in conjunction with the VCR. If it is used in conjunction
with the VCR 20, for example, you would obtain 28158 bytes free for
basic or in cartridge mode, where the program stored in its 8K of Ram
will automatically run when the machine is powered on.

You can purchase the VCS as a motherboard, without Ram, or already
fitted with 8K of Ram. In both cases, the battery neceassry for
back up is not provided. (An ordinary 4.5V battery is perfectly
adequate).

The paper is quite fragile after 38 years, I'll try and work out how to scan it safely.

[srowe]

Here's a diagram of the jumper block

It controls where the onboard RAM is mapped and the write protect.

[Gyro Gearloose]

What kind of paper is "quite fragile" after 38 years?

[srowe]

What kind of paper is "quite fragile" after 38 years?

Just cheap copier paper, it feels quite 'soft' and the staples are small and pulling through the paper.

[Gyro Gearloose]

I think I know what you mean, have you tried scanning with your phone? Then you don't need to crack open the paper quite as much.

[srowe]

Investigations were delayed by glacial delivery of RAM chips from China plus hunting down a dry joint.
As expected the jumper block allows selecting the 8K between BLK1 and BLK5 plus making it read-only. I haven't been brave enough to connect a battery, I'm not sure what voltage is expected (there's a 1K2 resistor in series).

[Vic20-Ian]

I have one of these and fairly sure it was meant to be a 9V battery backup for RAM.

I will look for the instructions