Moondoggie1968

So should a12 be grounded? I'm using a 28128 what about pin 26?

Ok, I've the the 3904 inverter wired up but need a little help. I've got a12 wired to a12 on the card edge as well as everything else down to a1. I've got the following pins on my 27128 left to wire up, can someone help with reference to the inverter. 1 - VPP 20 Chip Enable. 22 output enable 26 (No connection?) 27 Program strobe. I've got power and ground going to the inverter circuit, just need to wire up the input and output. Thanks Krock for the schematic.

That (is annoying), time to keep looking. Any other suitable replacements? 991209[/snapback] It should be possible to use a 2N3904 transistor and two resistors; some cartridges do this, but I don't know the exact resistor value. My suggestion would be to wire the emitter to ground, the base to A12 via 4.7K resistor, and the collector to /CE. Also wire a 4.7K resistor from /CE to VDD. The 2N3904 is a dime-a-dozen (literally, if bought in bulk) small-signal NPN transistor and should be widely available. A 2N2222 would be an acceptable substitute (slightly more expensive, but not enough to worry about). A small N-channel MOSFET might be an even better choice if you could find one, since you could eliminate the base resistor, but those aren't as easy to find. 991321[/snapback] Does anyone else have suggestions as to what value of resistors to use? What would be the part number for a N-channel MOSFET, are they in the same packaging?

That (is annoying), time to keep looking. Any other suitable replacements? 991209[/snapback] It should be possible to use a 2N3904 transistor and two resistors; some cartridges do this, but I don't know the exact resistor value. My suggestion would be to wire the emitter to ground, the base to A12 via 4.7K resistor, and the collector to /CE. Also wire a 4.7K resistor from /CE to VDD. The 2N3904 is a dime-a-dozen (literally, if bought in bulk) small-signal NPN transistor and should be widely available. A 2N2222 would be an acceptable substitute (slightly more expensive, but not enough to worry about). A small N-channel MOSFET might be an even better choice if you could find one, since you could eliminate the base resistor, but those aren't as easy to find. 991321[/snapback] Looking @ a 2n3904 on an old 5 1/2" floppy drive may try this instead. Makes sense since we are only using 1 gate on the chip anyway.

High CMOS Inverters will not work properly either. You need a 74LS04 991081[/snapback] That sucks, time to keep looking. Any other suitable replacements?

Could someone please provide a definitive texted based schematic for a hex inverter and 27128 on a 24 pin board? I've got the following for the hex inverter to the 27128 pin 14 to pin 7 GND 7404 pin 28 to pin 14 VCC pin 22 output enable to pin 2 Output 1 how to connect the input to pin 1 is where I'm stumped. I've seen lots of different ass backwards, upside down, reversed contradicting diagrams that are starting to confuse me. I know I'm close, BTW, I'm using a 4069 which should work fine.

Got the pinouts handy for a 27128?

Sorry didn't read your post, will give those pinouts a whirl

Found a 74hct04 but it's on a board and don't want to desolder it and ruin the device although I don't use it. Found some 4069's from an old Pay Descscrambler project, from what I have research they should be pin compatible. Does anyone have the schematic to add the hex inverter in text form? The pics above are kind of blurry. 4069 will work, right? I'm using 27128 *64k chips

Even if I'm going to put one game on it? Even small ones copied to fill the chip? The 28 pin atari age boards don't seem to have one.

You had any luck making a 2764 work on an old ATARI board yet? 980907[/snapback] I just put my prototype board together and doubled up river raid(32k) to make it fit the 64k chip. I'm using a 27c128 chip. I hooked up everything but the following on the 128 chip pin 1 27 26 22 does anyone know if they should grounded or set to +5? do I need a 7404 to get this to work? I'll post some pics in a bit.

I watched the whole thing, pretty cool!

The video touch pad was the last controller I needed before I had all of them. Got this little gem. http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewIt...Q%3ACA%3A1&rd=1 Box wasn't it good shape but it was there and the controller and star raiders keypad overlay were mint. had a copy of star raiders in a box of atari's I bought and had to see what it was all about. as far as the carts and eproms It wouldn't be hard to solder a ZIF socket onto a cart and burn a couple of eproms with common roms and even demonstrate them in the cart.

I'm just getting into burning my own roms, want to get 1 game to work first, then maybe my own multicart (dip switch).

Here's a quick and dirty port I did tonight, this is a great game and thought I'd share for those of you who have a dreamcast. Been playing this game on PC emulators for a while and it's always great. Turns out it works great on the Dreamcast Atari Emulator too, although there is some lag the faster the game gets but worth a look. looking forward to playing this great game on some real hardware real soon once I get my eprom burning station going. http://computerdirect.homeip.net/FallDown/ Click the above link to download it since I can't attach it. Let me know what you think.

Here's a quick and dirty port I did tonight, this is a great game and thought I'd share for those of you who have a dreamcast. Been playing this game on PC emulators for a while and it's always great. Turns out it works great on the Dreamcast Atari Emulator too, although there is some lag the faster the game gets but worth a look. looking forward to playing this great game on some real hardware real soon once I get my eprom burning station going. http://computerdirect.homeip.net/FallDown/ Click the above link to download it since I can't attach it. Let me know what you think.

I guess so 981104[/snapback] Just kidding! you obviously know your $hit.

Thanks for the correction! Are you sure you know what you're talking about?

What were you smokin'?

Here's the pinouts for the chip and edge connector (Looking at the bottom of the cartridge -- i.e. edge connectors first) Top D3 D4 D5 D6 D7 A11 A10 A12 A9 A8 +5V SGND --1- --2- --3- --4- --5- --6- --7- --8- --9- -10- -11- -12- GND D2 D1 D0 A0 A1 A2 A3 A4 A5 A6 A7 Bottom ____________ | 2716 | A7 | 1 24 | VCC [+5 V] A6 | 2 23 | A8 A5 | 3 22 | A9 A4 | 4 21 | VPP [Doesn't matter probably. +5V] A3 | 5 20 | !Output Enable (always on) [GND] A2 | 6 19 | A10 A1 | 7 18 | !Chip Enable (make high bit) [inverted A12] A0 | 8 17 | D7 D0 | 9 16 | D6 D1 | 10 15 | D5 D2 | 11 14 | D4 GND | 12 13 | D3 |__________| ____________ | 2764 | VPP | 1 28 | VCC [+5 V] A12 | 2 27 | !Program Strobe (no connection?) [+5V] A7 | 3 26 | No Connection A6 | 4 25 | A8 A5 | 5 24 | A9 A4 | 6 23 | A11 A3 | 7 22 | !Output Enable (always on) [GND] A2 | 8 21 | A10 A1 | 9 20 | !Chip Enable (always on) [GND] A0 | 10 19 | D7 D0 | 11 18 | D6 D1 | 12 17 | D5 D2 | 13 16 | D4 GND | 14 15 | D3 |__________| Sorry, I guess this doesn't look very good without a proportional font.

I'm thinking that about mine, next step, POT teardown and sandpaper. if that doesn't work time to dig up new 1 meg pots. Why do driving controllers never have this problem?

I'm also intrested in using 28 pin EPROMS on old carts so if you figure it out please post your results with picures and instructions please as my current porgrammer (soon getting a new one) is unable to burn DIP 24 chips and DIP 28 is my ownly current option and I got a slew of old atari carts to recycle in the mean time and all Igot also is 28 pin EPROMS (lots of 2764, 27128, 27256) Shawn Sr. 979749[/snapback] Just spec'd out my 24 pin board, and adapting it for 28 pin daughterboard and using what I can see from the AA store pics as a reference for to verify my pinouts. should have some text based schematics by tomorrow.

Absolutely! But for the same reason they don't put a cart port on a FB2, they don't want to be inundated with calls servicing 30 year old hardware. They market more to the general public rather than the atari junkies like us. The ability to easily ad the cart port shows the engineers had us in mind through the design process.

Of course I would need to purchase my very own flashback 2 in order to accomplish this. Which would be entirely legal, especially in Canada.

I've got the next 3 days off and wanted to get a headstart getting this eprom burner working and using the hardware I've got. There's not enough photos of the 28 pin boards atleast the bottom for me to confirm the connections. If some had the silkscreen designs for a 28 pin eprom board I should be able to adapt a 24 pin cart and be able to test my burnt eproms. Even if I have to add caps and inverters. I will probably order from AA tomorrow, once I decide all of what I'll need and how many of each. My ebay account has been busier than ever Thanks Chris