atari2600land's Blog

When you tear it apart you might be able to see if the plastic screen overlay can slide out via the area with the circuit board.

 

You might find useful info in the latest builds of MESS:

I mentioned Microvision, and it’s certainly a significant one. The driver was added in 0.148, and is still considered non-working and from my brief testing of Connect 4 it’s easy to see why, the pieces rarely end up where you tell them to drop and, an it seems entirely random that the computer decides to drop a piece where it wants one. Clearly there is still work to do, but it’s an important system to have emulated, it’s generally considered to be the first handheld video system, and the actual game cartridges contain no ROM chips, but instead MCUs with internal ROMs, so simply having them dumped is a miracle (even if I think there is some question over possible bad bits) Here are some screenshots from Connect 4 running.

 

(Microvision screenshots.. not specs of dirt on your screen)

 

So before you ask if I’m serious, yes, I’m serious, those are the screenshots, the unit is so early it had a resolution of just 16×16 pixels, and the pieces for one player are represented with a 2×2 cross-hatch pattern, and the other solid 2×2 squares. That’s it, here are some enlarged versions of the same thing, just so that you can see them on a monitor! You’ll definitely want to run these with a high -prescale value in MESS if you don’t just want to see a washed out blur!

 

They must have figured out how the LCD works in order to get as far as they have.

Where can I get the Connect Four Microvision ROM they used?

See the pictures on http://atarihq.com/danb/MicrovisionCarts.shtml

 

The Microvision cartridge is kinda like a 2600 cartridge. There's the PCB which holds the chips and other components, and the plastic shell (which on the Microvision also has the screen and keypad overlays). You need to replace the PCB with a brand new one holding the microcontroller and any other chips & components.

 

The bottom of the cartridge PCB is an edge connector which completes the circuit with the LCD controller, keypad, dial, speaker & battery. (See the pinout on http://atarihq.com/danb/Microvision.shtml#cartconnector )

 

I'll see if I can dig at the MESS code and see if it has any hints on the LCD controller.

So I can take the chip out and put in my own? I'm confused. Does the chip just simply pop out or would I have to cut something out and solder it back together? I looked at the second link and it's all Greek to me.

I'm confused as well. Is the plan to emulate the TMS1000 + game ROM with the propeller chip?

I'm confused as well. Is the plan to emulate the TMS1000 + game ROM with the propeller chip?

 

I guess you could phrase it like that. The ultimate goal is to produce a working Mircovision game that works on a Microvision console (by any means necessary!)

No need to emulate the TMS1000 CPU, just write the code for the CPU that's on the Propeller.

I'm sorry if I am confusing you.

 

The Microvision cartridge is two main parts - the plastic case and the circuit board (which holds the TMS1000 CPU). To make a new Microvision game you need to replace the circuit board with a brand new one holding the microcontroller and any support chips & components. This is how 2600 homebrews are often made. You open a donor cart and drop in a new circuit board.

 

The new circuit board would be the same size & shape as the Microvision circuit board with the same edge connector, which is the interface to the LCD controller and other stuff in the Microvision main unit.

 

Yes, this does mean that you will have to learn enough about electronics and circuit design to understand something like http://atarihq.com/danb/files/Microvision/PinballCart.pdf so you can put all of the necessary pieces in place to replace the TMS1100 with your microcontroller of choice.