VB Cartrige Production…

The cheapest reprogramable cart would use a 16 bit flash rom and a VB to PC link cable to perform the actual flashing. So in quantitys of 100 the cost breaks down like this:

Origional VB cart (for the edge connector) $1-$4
Flash Rom: $3-$10
New Circuit Board: $6
PC Link Cable: $3-$15

So you could make carts for around $13-$35 apiece, but your R&D on this would be around $400 to make the first cart. so to make your mony back you need to sell 100 carts at around $50 or 20 carts at $100 apiece. With a net investment of $4,000 before yo can sell your first cart.

David

Its not that simple. While we know 98% of what you need to do to make a reporgramable cart there are several ‘details’ that need to be worked out.

For example what ‘spare’ pins on the vb edge connector can you programaticaly controll, and that are stable at boot. If ther are not enough spare pins than we would need extra logic chips to reinterpet a write to expantion ram as an initiation of the flash programming sequence. (I keep mening to toss the VB on my logic analyzer to solve this one)

We need to verify that you can in fact make a boot loader reside at the top of the rom that redirects the interupt table. And develop the code to program a flash rom, it looks straight forward but some flashes are very timming dependant. (Im 98% sure this is trivial, but….)

And finaly you would need to develop a relyable link cable to pc protocol. The basic concept of link port communication is understood, but things like handshacking and error checking get tricky. (this is the easiest one by far, since so much work has been done on it. But as always developing new software on an unknown system has its hurdles)

Basicaly, if you can’t figure out what parts you need, chances are that you don’t have enough low level hardware/software experience to pull it of. With that said I am a firm believer that resolve can overcome any limitation (including lack of knowlege). So if you are serious I can show you what you will need to do, as can several other people here.

David