Can I burn Basic C to an eprom?

[mimo]

And use it to replace Basic B in my 800XL?

If so, how?

Thanks

[MEtalGuy66]

And use it to replace Basic B in my 800XL?

If so, how?

Thanks

 

Yep. Get the BASIC C ROM image. Burn it to a 2764 EPROM, and make a small socket adaptor to get the 2764 to work in place of the basic rom (just adapt the pinout)

[yorgle]

And use it to replace Basic B in my 800XL?

If so, how?

Thanks

 

If you can give me the Atari Coxxxx number for the BASIC C rom, I've probably got one you can have. I recently purchased a whole mess of Atari chips in an attempt to resurrect my dead 600xl. I know there are at least 6 roms in the pile.

[peteym5]

Best Electrons sells the Basic-C EPROMS. Wasn't there a recent thread on here about Turbobasic XL on an internal Eprom or Cartridge?

 

http://ataripal.googlepages.com/turbobasicxl

 

Turbobasic inside of the computer or something.

Edited October 26, 2007 by peteym5

[re-atari]

And use it to replace Basic B in my 800XL?

If so, how?

Thanks

A few months ago there was a topic dealing with this very question, check it out here . I posted an image how to rewire a standard eprom into a cartridge in this topic, so if you have a eprom burner at hand, you're good to go.

 

re-atari

[Kyle22]

Hello.

 

I have been trying (unsuccessfully) to upgrade my BASIC rev. A cart to rev. C. I sent the rev. C file to my EPROM burner (Needham's SA-20), starting at 0 -> 1FFF, then burned a 2532 from 0 -> 0FFF, and another 2532 from 1000 -> 1FFF.

 

I plugged them into the BASIC cart board C012963, and does not work. Both chips verify, I even read a 2764 with BASIC C on it, that I had in my 1200XL, and compared it, it verified too.

 

What am I doing wrong???

 

Thanks for your help!

 

-Kyle

[atarifan49]

Hello.

 

I have been trying (unsuccessfully) to upgrade my BASIC rev. A cart to rev. C. I sent the rev. C file to my EPROM burner (Needham's SA-20), starting at 0 -> 1FFF, then burned a 2532 from 0 -> 0FFF, and another 2532 from 1000 -> 1FFF.

 

I plugged them into the BASIC cart board C012963, and does not work. Both chips verify, I even read a 2764 with BASIC C on it, that I had in my 1200XL, and compared it, it verified too.

 

What am I doing wrong???

 

Thanks for your help!

 

-Kyle

 

Your trying to use EPROMs in a board that was designed for ROM chips with slightly different pin outs. You either need to modify the cartridge board for the 2532's or purchase a two-chip 2532 cartridge board from B&C or Best.

[re-atari]

Hello.

 

I have been trying (unsuccessfully) to upgrade my BASIC rev. A cart to rev. C. I sent the rev. C file to my EPROM burner (Needham's SA-20), starting at 0 -> 1FFF, then burned a 2532 from 0 -> 0FFF, and another 2532 from 1000 -> 1FFF.

 

I plugged them into the BASIC cart board C012963, and does not work. Both chips verify, I even read a 2764 with BASIC C on it, that I had in my 1200XL, and compared it, it verified too.

 

What am I doing wrong???

 

Thanks for your help!

 

-Kyle

If you're using an XL, I'd just build me a conversion socket that takes a 2764 eprom to replace the built in rom. Check the topic I referred to in the previous post, you'll find all the info you need there.

 

Rewiring a cart to take a 2764 requires the same kind of tinkering. I homemade me an Assembler Editor cartridge from a surplus Star Raiders this way back in 1986, and it still works to this very day. Go about as follows:

Program the romfile in a 2764. Then bend out pins 1, 2, 20, 23, 26, 27 & 28. Insert the eprom in the left 2564 socket flush with the bottom side, so that pin 1, 2, 27 & 28 extrude on top of the socket. Make sure the bent-out pins do not make contact with the socket. Use a piece of wire to connect 2764 pin 1, 27 & 28 together and wire them to 2564 pin 24. Wire 2764 pin 2 to 2564 socket pin 21, 2764 pin 20 to 2564 socket pin 20 and 2764 pin 23 to 2564 socket pin 18. The 2764 pin 26 is N.C., so you can leave it as is.

 

re-atari

[Kyle22]

Thanks for the info. I did a little research, and found that one of the two chips in the BASIC A cart is 2532 compatible. The other has the select line inverted in the chip for A12. Basically, A12 selects one chip (low) or the other (high). The two sockets are pin for pin in parallel. There is no different chip selects between the two sockets.

 

I am going to burn an 8K 68766 (24 pin) and try it, leaving the other socket empty. If that doesn't work, I'll go the 2764 route. I'll post my results here.

 

I erased those 2532's I tried in the cart, and burned USD in them. Those 2532's are good for USDoublers in 1050 drives that have the mask ROMs if you don't want to change the jumpers.

 

 

-Kyle

[re-atari]

I am going to burn an 8K 68766 (24 pin) and try it, leaving the other socket empty. If that doesn't work, I'll go the 2764 route. I'll post my results here.

 

Do check beforehand if a 68766 really is pincompatible with a 2564.

 

If you're going to do the 2764 mod, there's a way to combine 2 BASIC versions in one cartridge. Follow the instructions I posted above to build an adaptor socket, but use a 27128 16Kbyte eprom instead of 2764. Program one BASIC version in the lower 8K block and the other version in the high 8K. Solder a 4k7 resistor from pin 26 to 2564 socket pin 24 (+5V), and an on/off switch from pin 26 to 2564 socket pin 12 (GND). When the switch is closed pin 26 (address line A13) is low, selecting the lower 8K block. With the switch open A13 is high, thereby activating the high 8K.

 

BTW: the same rule of thumb applies to 8Kbyte game carts. For example, using a 8 pos. BCD switch and some careful rewiring you can put a single 27512 eprom holding 8 romfiles in one cartridge casing. And it still doesn't end there either: I built an adapter socket with a 16 pos. BCD switch for my XL's OS. It holds a 28F020 flashrom in which I programmed the romfiles for 16 OS-versions. Works like a charm.

 

re-atari

[Kyle22]

Thanks for all the info!

 

I found a 68764 EPROM, pin compatible w/ 68766. It was $11.99 + 5.95 shipping (ouch)! but it works perfectly in the BASIC rev. A cart. Take out both mask ROMs, burn the 68764 or 68766, and put it into EITHER socket on the cart. board, leaving the other one empty.

 

I have a 2764 with BASIC C on it, so I set the burner for 2764, and read the chip. Then changed type to 68766, put in the 68764! and burned it. I chose "Intelligent 1ms 3x" algorithm.

 

I was a little afraid to burn it, because my burner only had 68766 listed. I looked at both datasheets, and could find no real differences.

 

Anyway, it works fine. Hopefully my little experiment may be of help to others who want to make a ver. C cart, and have some of those expensive 68764 or 68766 chips sitting around.

 

-Kyle

[ClausB]

Hopefully my little experiment may be of help to others who want to make a ver. C cart, and have some of those expensive 68764 or 68766 chips sitting around.

Good work! A much cleaner solution than building an adaptor circuit.

 

I remember the MCM68764 from the mid-80's, when it cost about $40!

[Roydea6]

Thanks for all the info!

 

I found a 68764 EPROM, pin compatible w/ 68766. It was $11.99 + 5.95 shipping (ouch)! but it works perfectly in the BASIC rev. A cart. Take out both mask ROMs, burn the 68764 or 68766, and put it into EITHER socket on the cart. board, leaving the other one empty.

 

I have a 2764 with BASIC C on it, so I set the burner for 2764, and read the chip. Then changed type to 68766, put in the 68764! and burned it. I chose "Intelligent 1ms 3x" algorithm.

 

I was a little afraid to burn it, because my burner only had 68766 listed. I looked at both datasheets, and could find no real differences.

 

Anyway, it works fine. Hopefully my little experiment may be of help to others who want to make a ver. C cart, and have some of those expensive 68764 or 68766 chips sitting around.

 

-Kyle

 

I was able to get a few of these chips, I could not find any datasheets, and my burner didn't have the option for "Intelligent 1ms 3x" so I used binary algorithm. I installed one into a cartridge. Works great. ? peek(43234) before change =192 and after the chip change =234.. without the cartridge in =96. I would like to see the datasheets.

 

Thanks for the info..

 

Now back to desoldering the chip from motherboard.

[puppetmark]

I was able to get a few of these chips, I could not find any datasheets, and my burner didn't have the option for "Intelligent 1ms 3x" so I used binary algorithm. I installed one into a cartridge. Works great. ? peek(43234) before change =192 and after the chip change =234.. without the cartridge in =96. I would like to see the datasheets.

 

Does this help?

 

MCM68764_1_.pdf

[Slor]

If anyone needs a basic replacement burned to a 68764, feel free to drop me a line. I can send you one out at cost + shipping.

 

James