Looking for Atari chip or IC replacement (C25953-20 or GAL22v10)

Hi all,

together with @Klyde, I'm putting together a project for a friend to expand a 65XE to 128K RAM, but we would need a C25953-20 EMMU which, as you may know, is quite difficult to find. Do you have one or know where I can get one? Or is there somebody to program a GAL22v10 for us (neither I nor @Klyde don't have a programmer)?

Thank you.

 

A different option would be: does someone has a 130XE for sale? Or an already expanded (128K or more) A8 machine? I heard that there's a new cartridge that expands RAM to 1MB but cannot find the reference on the web. It could be coupled with a SIO2SD and make a very good game and application A8 computer. Thanks in advance for all the info you can provide. After 5 years of Atari Sector and AOC, I'm still a beginner when it comes to A8... Too bad, Dazza, too bad.

 

Good luck, Daz.

I'm afraid I have no spare Atari chips or any Atari classics for sale right now... Brenski, has had some Atari bits for sale off/on of late -

He has some ICs here but they don't look to be of the correct type -

https://www.ebay.co.uk/itm/Eprom-Co...632554?hash=item23ed18102a:g:Q~kAAOSwYQRe5HfZ

Sorry, Daz. I can't help at the moment.

 

Thank you anyway, Baz. I know we can always count on you when it comes to mutual help on retrocomputing projects. What about the techies orbiting around the AOC planet? Richie? Allan? Paul? Robofruit? thx

 

Hi Daz or even ol Graham
Yes I can program up a GAL for you, I've only got 16V8's which should work as replacements for both the 16R8 & 16L8's . You will require an LS95 as well to use a GAL sits in I U35 .

I've not tried using this but welcome to burn one for you from the JEDEC file on Mathy;s site
http://mathyvannisselroy.nl/special stuff.htm#CO25953
If you download the VDHL file se note below.

""The attached design fully works! Just replace both U34 and U35 in your 130 XE
with IC sockets and use the attached jedec file to burn a gal. Make sure pin
12 is tied somewhere either gnd for 130xe comp. or vcc for 800xl comp.
Actually I had to flip a bit in the (gal.jed) jedec file manually to make pin
13 an input. Since the halt signal is not used the damned vhdl compiler sets
all unused OCLM pins in simple mode of the gal to output. Since the halt
signal is still supplied to pin 13 this would be a shortcircuit.
If you want to compile this vhdl file and use your own jedec file no probem,
just make sure you bend pin 13 out of the IC socket so that it does not get
any signal. ""

It also mentions 16V8 as well.

Just let me know what you would like

 

Thank you Graham for your kind reply. @Klyde is modding the 65XE and I know he would prefer the GAL22V10 solution because of the additional LS95 (or LS74) chip needed when you use the 16v8. But I'll let him choose what's best.

 

Hi Graham, thanks for your help. The best option would be to use a GAL22v10, it avoids the need of the extra LS95.

Jedec file can be found here:

https://github.com/mikulski-lab/C25953-emmu/tree/master/gal22v10/wincupl

We can provide a GAL22, David?

 

Our Post crossed
I'll have a look o n GITHUB now.! If you can find a GAL JEDEC file that work I'm happy to program one, I've however not got any 22V10 only 22V8's
note these are both 24 pins devices not 20 pin And that the motherboard has a 20 pin socket
So for neatness the 16v8 and an LS95 would be just plug in and work, the 22v10 would have 4 extra legs to deal with, one of which would be in power or Ground pin which ever way you chose to move the chip (it being programmable afterall)

 

Just checking and yes the Motherboard he has didn't have the U35 socket space. and there are 4 pins hanging off the end of the original 20 pins space, with a couple of bits of wire.
Happy to help whatever way, but I'd have to get a 20V10 you can have a 16V8 as have a number of them.

 

Looks like they are a rarity 20V8's no problem 20V10's Hmm.

 

I guess so. Never handled one before, and to be honest I wouldn't know where to buy one. I'll look for it in UK so I can have it sent to Graham's place quickly and, hopefully cheaply.