strange homebrew cart.

[CrAlt]

Hello all. Vic noob here.



I got this cart with my vic 20. Its for my packet radio modem. The modem plugs in to the USER port uses a program thats called "TERMINAL 40". I type SYS40960 in to start the software. All good.

But the other day i noticed that when the cart is plugged in my ram goes up to 11775.
Is this cart also a 8K expansion cart?

The board says "VIC 20 16K ROM CARD"
"GLOUCESTER COMPUTER INC"
"GLOUCESTER MA 1983 USA"

There are 4 spots for chips. LOW1,HIGH1,LOW2,HIGH2
In high2 it looks like an EPORM (D2764A)
In LOW1 we have a HM6264LP-15 chip.

I googled that and learned that it is a 64 k SRAM chip.

How do i find out how much total ram this cart is adding? Anyone think it will work as a real 8K expander?

Thanks

[Leeeeee]

But the other day i noticed that when the cart is plugged in my ram goes up to 11775. :o
Is this cart also a 8K expansion cart?

Yes it is.

In LOW1 we have a HM6264LP-15 chip.

I googled that and learned that it is a 64 k SRAM chip.

How do i find out how much total ram this cart is adding? Anyone think it will work as a real 8K expander?

The HM6264LP-15 is an 8K byte low power static RAM chip so the cart will also work as just an 8K expander.

You could also, if you wish, replace the EPROM with another with any other 4K or 8K $A000 cart ROM image burned into it.

I would also assume that with two more 6264s and perhaps some wire jumpering the card could work as up to 24K bytes of RAM expansion.

Lee.

[CrAlt]

Cool!

Thanks leeeeeeee

[6502dude]

Since eprom on the board is in /BLK5 address space (you start your terminal program with sys40960), you should be able to pull the eprom from its socket and burn rom image of any 8K game and have it auto start.

This is a nice little board to have if you just want to play around a bit.

You will likely need 27C64 eproms for this board.

[CrAlt]

Since the terminal is at block 5 why doesn't it auto start?


I was reading about how the vic sets up its ram on the site in your sig...
http://www.8bitcentral.com/vicram.htm
"Another feature of block 5 is that programs stored in this area can be "auto-started" when the VIC is reset. Most cartridge games are located in block 5. You can tell because these games start automatically when you turn the VIC on"

[gklinger]

You should get yourself on the list for the MegaCart. I understand a slot has become available lately...

[CrAlt]

How do i go about getting on that list?

That project looks cool as hell.

[gklinger]

How do i go about getting on that list?

I think you just did.

6502dude is the hardware designer behind the project and he can add you to the list.

That project looks cool as hell.

I've had the opportunity to play with the prototypes and it's every bit as cool as it sounds. It is shaping up to be the say all, end all of VIC-20 cartridges.

[Mike]

Hi, CrAlt,

welcome to Denial!

I just would like to point out, that this thread better fits into the 'Hardware and Tech' section (could one of the mods move it to there?).

"Another feature of block 5 is that programs stored in this area can be "auto-started" when the VIC is reset. Most cartridge games are located in block 5. You can tell because these games start automatically when you turn the VIC on"

They can be auto-started, but for this to happen, they must feature the A0CBM signature beginning at $A004. This is obviously not the case here.

Greetings,

Michael

[nbla000]

How do i go about getting on that list?

I think you just did.

6502dude is the hardware designer behind the project and he can add you to the list.

Yes send a PM to him.
The latest small SMT PCB layout that fit inside a common CBM case is ready and we will test it soon with latest eproms with Bridge too, if all will be ok as we think we will contact all members on the list to pay an account to start mass production

That project looks cool as hell.

I've had the opportunity to play with the prototypes and it's every bit as cool as it sounds. It is shaping up to be the say all, end all of VIC-20 cartridges.

Thanks Golan, it was a very fun but hard work and it's a pleasure for me to hear these words.

[ral-clan]

I think I have one of these boards too, but mine is completely populated, with a DIP switch bank where the solder pads are in the middle. I'll try and remember to check when I get home.