Does the O2 have 'Helper' Chips in Games

[christo930]

Did the O2 ever have any games that had onboard RAM like the 2600?  If not, was it possible? Some 2600 games had a fairly substantial amount (10x the internal RAM) on the cartridge itself.

Had the O2 been the huge roaring success the 2600 was and the will to spend money to make better games and higher sales, was something like a DPC+ chip possible?  Does the design preclude either RAM or a DPC+ chip?

[ozyr]

The only thing I'm aware of is an extra chip for SID The Spellbinder, which contained extra word phrases for The Voice.

As for extra RAM or a DPC chip, there are only a handful of people that can answer that, and I'm not sure if they are on AA (I know the most knowledgable person is not).

[carlsson]

Does the C7420 BASIC cartridge for the Videopac+ G7400 count? It has its own Z80 with 16K RAM and 16K ROM so pretty much a self contained computer.

[DanBoris]

On 5/4/2020 at 11:51 PM, christo930 said:

Did the O2 ever have any games that had onboard RAM like the 2600?  If not, was it possible? Some 2600 games had a fairly substantial amount (10x the internal RAM) on the cartridge itself.

Had the O2 been the huge roaring success the 2600 was and the will to spend money to make better games and higher sales, was something like a DPC+ chip possible?  Does the design preclude either RAM or a DPC+ chip?

I am not aware of any O2 cart that had extra RAM in it. In theory it should be possible. 

[Mikebloke]

I don't think anything that is normal sized carts have anything special, not even the Parker or imagic games as far as I'm aware. You have the chess module with the big brick that is supposed to sit on top of your machine awkwardly though. Guess the one ozyr mentioned might be the only one. 

 

I don't think there is anything limiting a dpc+ style system for a new cart, it's just not been developed enough to warrant it. The keyboard capability might make it attractive for some unique features I guess. 

[+pboland]

First off, I don't have the technical know how to really implement anything like this but here are some thoughts. I am in the states so my comments will be from that point of view.

 

On 5/27/2020 at 12:55 PM, Mikebloke said:

I don't think anything that is normal sized carts have anything special, not even the Parker or imagic games as far as I'm aware. You have the chess module with the big brick that is supposed to sit on top of your machine awkwardly though. Guess the one ozyr mentioned might be the only one. 

 

I don't think there is anything limiting a dpc+ style system for a new cart, it's just not been developed enough to warrant it. The keyboard capability might make it attractive for some unique features I guess. 

From what I've seen the chess module is the only upgrade that happened to the OD2 (actually the G7000) line. But, it doesn't work with NTSC OD2's. I've always wondered what extra power it really gave the OD2 and if it would be possible to make that added power standard on new PCB's and what that power would truly add...

On 5/14/2020 at 6:54 PM, carlsson said:

Does the C7420 BASIC cartridge for the Videopac+ G7400 count? It has its own Z80 with 16K RAM and 16K ROM so pretty much a self contained computer.

But then the thought of the OD3 comes to mind. I know in Europe the G7400 is basically the OD3. Is it possible to build all the upgrades of the G7400/OD3 onto a standard OD2 PCB?

 

That itself would be a great upgrade for all OD2's. Then all new homebrews could be based on the G7400 hardware capabilities and work on all machines G7000/OD2 & G7400/OD3 (of course there is still the issue of NTSC & PAL to deal with). And yes there would need to be some kind of logic built in to recognize if it is already in a G7400.

 

I know there would be a lot of issues with this idea but it was just a thought. I don't know if it is really possible to build that kind of upgrade that could fit in a standard OD2 cart shell. I was kind of hoping it would use modern components to achieve that. Of course even it is was possible, it most likely isn't practical.

 

I don't know. I was just thinking out loud.

 

[carlsson]

From what I understand, the C7010 contains a 4.43 MHz NSC800 which is Z80 compatible, 2K RAM and 8K ROM. That can be compared with the C7420 BASIC module which has a 3.58 MHz Z80, 16K RAM and 16K ROM.

 

Without knowing more about the topic, I would assume if you make a cartridge with a Z80 and enough RAM (32K?) to soft load the ROM portions, it might allow Chess and BASIC to run. But in order to turn a O2 into an O3, you need to update the graphics system as well, plus that the onboard 8048 supposedly runs faster (5.91 MHz vs 3.58 MHz) on the O3, and also differences on the onboard RAM.

[+pboland]

On 6/28/2020 at 1:23 PM, carlsson said:

From what I understand, the C7010 contains a 4.43 MHz NSC800 which is Z80 compatible, 2K RAM and 8K ROM. That can be compared with the C7420 BASIC module which has a 3.58 MHz Z80, 16K RAM and 16K ROM.

 

Without knowing more about the topic, I would assume if you make a cartridge with a Z80 and enough RAM (32K?) to soft load the ROM portions, it might allow Chess and BASIC to run. But in order to turn a O2 into an O3, you need to update the graphics system as well, plus that the onboard 8048 supposedly runs faster (5.91 MHz vs 3.58 MHz) on the O3, and also differences on the onboard RAM.

I kind of knew the O3 in an O2 was pie in the sky, but does the hardware in the C7010 really add anything to the O2 other than the ability to play chess?

[carlsson]

Exactly how the G7000 operates with a secondary CPU on the cartridge is for someone else to answer. At least National Semiconductor claims the NSC800 is fully Z80 compatible. Perhaps at least other board games would be doable, depending on which portions of the O2 hardware the cartridge can access.

[Mister-VCS]

On 5/5/2020 at 5:51 AM, christo930 said:

Did the O2 ever have any games that had onboard RAM like the 2600?  If not, was it possible? Some 2600 games had a fairly substantial amount (10x the internal RAM) on the cartridge itself.

Had the O2 been the huge roaring success the 2600 was and the will to spend money to make better games and higher sales, was something like a DPC+ chip possible?  Does the design preclude either RAM or a DPC+ chip?

e.g. Monkeyshines

 

[jimj]

On 7/25/2020 at 11:56 PM, Mister-VCS said:

e.g. Monkeyshines

I have always assumed the "Expanded Memory" games were referring to ROM, not RAM.  Can anyone confirm if this is correct?

[carlsson]

Yes. The first batch of Videopac games were 2K ROM. Through bank switching (select/address lines) you can access four of those for a total of 8K ROM. The games featuring 2x2K = 4K ROM were labeled Expanded Memory. Possibly though the cartridge contains helper circuitry for selecting the right ROM chip, so in that way it is a "helper chip" even if all it does is read the desired chip?

Edited July 29, 2020 by carlsson