156 replies to this topic

[CPUWIZ]

Bruce Tomlin, on Fri Aug 4, 2006 7:36 PM, said:

Yeah, looks like it will be $5.00 for the bare board

Mmmmmh, competition.

Almost Rice, on Fri Aug 4, 2006 9:59 PM, said:

Why did you have to import them?

Because it's cheaper.

[kenfused]

I guess I don't ever seeing myself going with a new pokey board unless some large abundant and cheaper supply of pokeys and be found. The only exception might be if pokey could be mapped at a different address so I could still have some RAM on there too. Probably could map one somewhere lower in memory that doesnt interfere with anything, or with the HSC, or at the very least give it a smaller footprint than 16K. When you add up the cost of board+pokey+case it is probably better to just cannibilize ballblazer carts otherwise (at least until the one place runs out of cases of them). For SRAM it might be nice to support both dip sizes. The skinny dip might be easier to fit on the board, but the wider dip is easier to find (but I haven't looked too hard yet).

[Bruce Tomlin]

kenfused, on Sat Aug 5, 2006 12:29 PM, said:

I guess I don't ever seeing myself going with a new pokey board unless some large abundant and cheaper supply of pokeys and be found. The only exception might be if pokey could be mapped at a different address so I could still have some RAM on there too. Probably could map one somewhere lower in memory that doesnt interfere with anything, or with the HSC, or at the very least give it a smaller footprint than 16K. When you add up the cost of board+pokey+case it is probably better to just cannibilize ballblazer carts otherwise (at least until the one place runs out of cases of them). For SRAM it might be nice to support both dip sizes. The skinny dip might be easier to fit on the board, but the wider dip is easier to find (but I haven't looked too hard yet).

I tried, and I couldn't get both skinny and wide RAM chips to fit because of that @#%!@ screw post, and the narrow neck too. I just couldn't get enough lines up there at the design rules I was working with. And there's really no point in going multi-layer. And I've got tons of narrow RAM chips that I've scavenged over the years, especially the ones that they used for 386/486 caches. (as someone else mentioned long ago, they might not be low power, but that's only a problem if you want to use a battery).

But I agree that it's kind of going to be a problem to put a Pokey in every game when they're, what, five bucks each? We need an HSC-style inline cartridge, but that would be a bit of a pain to design, and how just sturdy are stacked 7800 carts anyhow?


So anyhow, last night I drew up some diagrams for the six main jumper combinations (ignoring 512K and 1M) on an image of the top copper layer, dug up all the parts I needed, and soldered a socketed board for a 128K game. Then this morning I burned a GAL and a 27C010 with Klax. Klax started up the first time. That's a good sign.

There is only going to be one GAL for most combinations. I have a GAL for 144K, but only Alien Brigade and Crossbow used 144K, and I think it's possible to arrange them to work on a 256K board. 512K and 1M require a 22V10 GAL, and I'll worry about those when someone is actually doing that big of a game. 256K should be plenty for now.

[Bruce Tomlin]

I just got a bunch of 74LS02 chips, so I'm all ready to make pre-loaded boards now.

Seeing as to recent developments, I need to charge $4 for a bare board, $4.50 for a board with a 74LS02 installed, and $6 with a bankswitch chip installed. Please specify the desired size for pre-installed boards. (8/16K, 32K, 48K, 64K, 128K, 144/256K)

Send e-mail to bruce@xi6.com.

[PacMan]

Email sent.

[Bruce Tomlin]

I've been working on some preliminary documentation:

http://atari7800.net/mini-ultra/

[DracIsBack]

Just wondering about this.