Little home project: ROM dumper

[SvOlli]

2 minutes ago, Mr SQL said:

I'm curious what values you retrieve for CBS RAM if you try a Tunnel Runner cart.  Answer may be related to the F8 Superchip question. Currently there are three ways to define it, low high or random. 

Since I don't have an CBM RAM cart, I can't test it (and the dumper isn't implemented yet). What is the most common (= cheapest) PAL cart I could get? (I don't use my NTSC machine very often, and here in Germany, PAL carts are generally cheaper to get.)

[Mr SQL]

On 8/10/2022 at 2:44 PM, SvOlli said:

Since I don't have an CBM RAM cart, I can't test it (and the dumper isn't implemented yet). What is the most common (= cheapest) PAL cart I could get? (I don't use my NTSC machine very often, and here in Germany, PAL carts are generally cheaper to get.)

Maybe Moutain King? I think @Rom Hunter would know the answer.

[Rom Hunter]

On 8/12/2022 at 3:27 PM, Mr SQL said:

Maybe Moutain King? I think @Rom Hunter would know the answer.

Mountain King doesn't exist in PAL format.

AFAIK there were no CBS RAM plus carts released in PAL format.

Edited August 20, 2022 by Rom Hunter

[Mr SQL]

On 8/20/2022 at 5:08 AM, Rom Hunter said:

Mountain King doesn't exist in PAL format.

AFAIK there were no CBS RAM plus carts released in PAL format.

Interesting CBS RAM technology was not available in PAL land, this may explain the confusion on standardizing the mappers to initialize. 

 

Surprising, Tunnel Runner and Mountain King would surely have been popular,

 

Perhaps CBS Electronics was afraid of knock-offs infringing on their IP like with the Canal SuperCharger?

[SvOlli]

On 8/10/2022 at 8:39 PM, Mr SQL said:

I'm curious what values you retrieve for CBS RAM if you try a Tunnel Runner cart.  Answer may be related to the F8 Superchip question. Currently there are three ways to define it, low high or random.

So, the dumper is implemented and committed. I can't test it with an original CBS cartridge, but I can tell you, what will happen as I've implemented it with the SuperChip cart: I'm doing a write of $FF to $F000. This will result in the value on the bus being $FF, if no-one writes to it. Since the write-port starts first, the $FF will be written to RAM, as they are one the bus and on-one else if pulling them low. When the read-port of the RAM is reached, the RAM already contains $FF. That is what I'd also write to the (E)PROM at that position, so it doesn't interfere, when (E)PROM and RAM are selected both at once.

[Mr SQL]

3 hours ago, SvOlli said:

So, the dumper is implemented and committed. I can't test it with an original CBS cartridge, but I can tell you, what will happen as I've implemented it with the SuperChip cart: I'm doing a write of $FF to $F000. This will result in the value on the bus being $FF, if no-one writes to it. Since the write-port starts first, the $FF will be written to RAM, as they are one the bus and on-one else if pulling them low. When the read-port of the RAM is reached, the RAM already contains $FF. That is what I'd also write to the (E)PROM at that position, so it doesn't interfere, when (E)PROM and RAM are selected both at once.

Very cool, I wonder if you could test an NTSC CBS cartridge with a PAL TV that has a vertical hold. 

[SvOlli]

7 hours ago, Mr SQL said:

Very cool, I wonder if you could test an NTSC CBS cartridge with a PAL TV that has a vertical hold. 

There is something you might have missed: the dumper works without a 2600. So the PAL/NTSC does not matter for dumping. I was just asking because I'm using PAL 99% of the time, so buying an NTSC cart does not make much sense.

[Fabriciotm]

On 6/5/2021 at 8:11 AM, Dionoid said:

Here are some pictures of my breadboard-setup of @SvOlli's Rom Dumper, but this time using an Arduino Nano, for which I added the code to his retrocartdumper project on GitHub.

 

Note that the Nano has the bare minimum of the required 20 GPIO pins for dumping of Atari 2600 cartridges. I had to connect the cartridge's address A12 signal to +5V, which basically works as the chip-select for the ROM. This means that only bankswitching schemes are supported which use hotspots within the cartridge ROM address space.

For most cartridges brands (e.g. Atari, Activision, Imagic, CBS, M-Network and Parker Brothers) this is sufficient. If you need support for dumping TigerVision's 3F or Superbanking cartridges, please use the Teensy++ 2.0 microcontroller instead.

Also, since the A6 and A7 pins on the Nano are analog-in only, writing to the the data bus is not supported on the Nano, but only on the Teensy.

 

Picture of dumping a PAL Fatal Run cartridge (which has F4 bankswitching + SuperChip) using a cheap €5 Arduino Nano clone:

 

Note that I had to lift the 24-pin cartridge connector on its legs as high as possible, because the connector wasn't tall enough to give the cartridges enough clearance when inserting them.

 

Instead of Nano, you can use the Arduino Mega Mini. Is the same Arduino MEGA 2560 R3 in a small board. I bought from Aliexpress for $5.

[Ecernosoft]

On 4/21/2020 at 12:20 PM, SvOlli said:

Now I can use some help.

 

I've gone through my collection of games and found the following bank switching types: 2k, 4k, F8, F6SC, F4, and F4SC.

 

I'm looking for some games / cartridges which utilize some of the more exotic bank switching types. I know I could use the Harmony Cart to mimic everything available, but to have a small collection of "testcarts" would be nice. So I'm looking for suggestions for carts with the requirements in the following order:

- cheap (that includes shipping to Germany)

- fun

- PAL

And also for using the Harmony Cart, a list a reference carts for a bank switching type with one available ROM per type.

Also note, that only non Harmony specific types are wanted, so no DPC+ .

There’s a 128k game I know of. (I don’t think it’s dpc+) and it’s an RPG.