1764 REU

[xlar54]

Hey, I recently got one of these, and Wikipedia article on it says:

"The 1700 and 1750 had a resistor at position R4 that, according to Commodore engineer Fred Bowen, compensated for subtle differences in the expansion port on the C64 and C128. The 1764 lacked that resistor. Bowen and other CBM engineers recommended against using a 1764 with a C128 unless the resistor was added, or a 1700/1750 with a C64 unless the resistor was removed."

Anyone know what this is about?  I dont want to take a chance at damaging my 128 due to not having this resistor installed.

[RobertB]

Anyone know what this is about?  I dont want to take a chance at damaging my 128 due to not having this resistor installed.

I've used the 1764 many times on various flat C128s and C128Ds.  No problems at all!

          Back from buying many C=/Amiga items
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          Robert Bernardo
          Fresno Commodore User Group
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[airship]

I've used my 1700 and 1764 on both C64s and C128s without problems. YMMV.

I'm sure Fred wouldn't have said anything unless it was a problem sometimes. He's a good engineer.

[Andrew Wiskow]

I removed that resistor on my 1750 when I first used it with a C64, but I've used it since then on C128's with no problem.

-Andrew

[SmallCleverDinosaur]

Hi everyone. This is somewhat off-topic but is there someone who has a 1750XL, 2MB REU made by Creative Micro Designs (CMD), or maybe has pictures of one?

There was also a "Super 1750 Clone" made by Chip level designs (CLD). Has anyone got one of those? Or pictures?

[RobertB]

Hi everyone. This is somewhat off-topic but is there someone who has a 1750XL, 2MB REU made by Creative Micro Designs (CMD)...

Yes, I have one.

There was also a "Super 1750 Clone" made by Chip level designs (CLD). Has anyone got one of those?

Yes, I have those, too.  Actually, there is one Super 1750 Clone which is exactly like a 1700/1764 but with more memory.  The other type is the small cartridge version with the same exterior as a common cart, like a 1750XL.

               Merry Christmas!
               Robert Bernardo
               Fresno Commodore User Group
               http://videocam.net.au/fcug
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[SmallCleverDinosaur]

Robert, do you have everything?

Could you take some pictures, that would be great!

[RobertB]

Robert, do you have everything?

Everything would encompass the entire universe! 

Could you take some pictures, that would be great!

I am on holiday until Jan. 12 and am away from my usual C= equipment.  I still take photos on film but have them transferred to CD -- that would delay things.  Also I'd have to open up the ram expanders for a look inside -- something that I don't like doing for fear of breaking the cases.  However, I can try.

               Truly,
               Robert Bernardo
               Fresno Commodore User Group
               http://videocam.net.au/fcug
               The Other Group of Amigoids
               http://www.calweb.com/~rabel1/
               Southern California Commodore/Amiga Network
               http://www.sccaners.org/

[Golan Klinger]

Anything in particular you want to know about them?

[Blacklord]

It strikes me that creating a clone 17xx that is entirely compatible with the C= articles really only requires the MOS 8726 REC.

Of course, finding a ready supply of these now days may be difficult...

[Golan Klinger]

It strikes me that creating a clone 17xx that is entirely compatible with the C= articles really only requires the MOS 8726 REC.

Of course, finding a ready supply of these now days may be difficult...

That chip has been thoroughly dissected and the functionality reproduced so it isn't outside the realm of possibility. I've found the REU in the 1541 Ultimate has rendered all my other REUs unnecessary.

[Blacklord]

Unfortunately the 1541 Ultimate weighs in at over $320 dollars (not including postage). Which is a little too much for me

Especially considering C64's can be picked up for $5 or so.

[RobertB]

Unfortunately the 1541 Ultimate weighs in at over $320 dollars (not including postage). Which is a little too much for me

Especially for those who just want a ram expander and nothing else.

                  Merry Christmas!
                  Robert Bernardo
                  Fresno Commodore User Group
                  http://videocam.net.au/fcug
                  The Other Group of Amigoids
                  http://www.calweb.com/~rabel1/
                  Southern California Commodore/Amiga Network
                  http://www.sccaners.org/

[Blacklord]

Unfortunately the 1541 Ultimate weighs in at over $320 dollars (not including postage). Which is a little too much for me

Especially for those who just want a ram expander and nothing else.

                 

Absolutely!

[Golan Klinger]

The point is that the technology is now fully understood and replicable. Creating a modern 2MB REU replacement is now doable and eslapion was talking about doing just that at WoC 2007. I don't know if he abandoned the idea but he was quite sure he could do it.

P.S. The 1541 Ultimate is like sex in that it's difficult to convey the appeal to someone who hasn't experienced it.

[SmallCleverDinosaur]

Many thanks Golan for the pictures of the 1750XL and the 1750 clone I was just curious as to what they looked like. By the way, how do you make your attached pictures in the forum clickable?

It strikes me that creating a clone 17xx that is entirely compatible with the C= articles really only requires the MOS 8726 REC.

Of course, finding a ready supply of these now days may be difficult...

As Golan said, the technology of the MOS 8726 is now fully understood and can be replicated. I have been thinking of using a PIC microprocessor to create a replica. But there are a few things to understand first. For example how DMA works. Does anyone have documentation of this? I've tried to find it on the internet with little success.

[Golan Klinger]

I was just curious as to what they looked like. By the way, how do you make your attached pictures in the forum clickable?

Use Postimage. It's free, provides those clickable thumbnails and even gives you the code to paste into your messages. Very handy indeed.

[RobertB]

Actually, there is one Super 1750 Clone which is exactly like a 1700/1764 but with more memory.

I will still try to take a photo of this variation of the Super 1750 Clone.  It has a massive sticker over the case, proclaiming that it is the "Super 1750 Clone"!

               Merry Christmas!
               Robert Bernardo
               Fresno Commodore User Group
               http://videocam.net.au/fcug
               The Other Group of Amigoids
               http://www.calweb.com/~rabel1/
               Southern California Commodore/Amiga Network
               http://www.sccaners.org/

[SmallCleverDinosaur]

Use Postimage. It's free, provides those clickable thumbnails and even gives you the code to paste into your messages. Very handy indeed.

Thanks Golan!

     I will still try to take a photo of this variation of the Super 1750 Clone.  It has a massive sticker over the case, proclaiming that it is the "Super 1750 Clone"!

Robert, you are too kind

[Blacklord]

I was just curious as to what they looked like. By the way, how do you make your attached pictures in the forum clickable?

Use Postimage. It's free, provides those clickable thumbnails and even gives you the code to paste into your messages. Very handy indeed.

Or use the attachment option under "Additional Options" when you post.

The forum is littered with broken external links where people have linked offsite images that aren't around anymore

cheers,

Lance

[SmallCleverDinosaur]

So I've noticed. That's sad. The pictures I have posted, I have linked to my own domain and I plan on keeping that for a long time so hopefully, my links won't be broken.

But using your or Golans technic is even better.

[Golan Klinger]

I like using Postimage as it allows me to link to the same images from multiple forums (if need be).

[Andrew Wiskow]

Creating a modern 2MB REU replacement is now doable and eslapion was talking about doing just that at WoC 2007.

Is he still talking about making a clone of the FD-2000, too?  Or has he dropped that idea?

[Golan Klinger]

I don't know. He hasn't said.