shoestring

I'll definitely keep that in mind. It will be nice to have Tramiel era 8bit Atari in my collection

' Commodore attack" . I suspect a power supply was responsible for this. A work colleague of mine picked up this 65xe and an 800xl off eBay. He described a buzzing sound and rolling picture ( sound familiar ?? ).I ended up repairing the 800xl which also had a single DRAM fault at U9, I replaced the whole stack of 8 with m3764s. The machines came with 3 power supplies, one of them was C70042-1 'The Logo' and the other two were identical but I had never seen those types before. All encased in epoxy and non repairable. Some vandal had also been poking around inside the 65xe and destroyed the variable resistor at R38, I suspect this is for the colour adjustment. After testing the 800xl & repairing it, I salvaged the leads+7 pin din connectors for a switching adapter solution and tossed the power supplies in the bin. I was rewarded with the 65xe for help with the 800xl, so now it's mine to fix. I have a really nice Tektronix TDS3054 scope to get the job done. Thanks for the troubleshooting points, I'll post some results once I make more progress.

The MT DRAMs were so far gone that my EPROM programmer ( Micromaster LV48 ) couldn't recognize them and was prompting to check device and position ( as though no device was installled in it ). Normally it will either pass tests or fail when it reads back the wrong value at a given address. I put some sockets in this already and installed some TI branded DRAMs. I'm more interested in upgrading it to 512kb which requires an SRAM package, it's requires more work but is more worth while than the 128kb mod.

DRAMs don't work that way. You need two because one makes up the upper 4 bits and the other makes up the lower 4 to give you 1 byte per memory address. The other two empty sockets give you a total of 128kbytes in a 130xe. They use the same PCB for both models.

Hi all. I have picked up a dead and battered 65xe that produces nothing but a black screen. It has what appears to be 2 x 64Kx4bit DRAMs ( MT 4067-12 ). Are these just 4464s? The data sheet seems to confirm the same pinout. I'm still getting nothing after replacing them with known working DRAMs which are a little faster. FYI I'm using a known working power supply which I use for my other Atari's. I tested the MT-4067 DRAMs out of circuit and they seem completely dead so I'm suspecting that a faulty power supply took these out and perhaps other circuitry as well. The 40 pin chip at the bottom left is stone cold compared to the other chips which run warm, looking at the circuit it appears that this chip is some kind of DRAM address decoder?? I'm just looking for some advice on probably causes before I start doing some troubleshooting of my own as I have no experience with the XE series and I'd like to get the memory in this upgraded eventually and the exterior cleaned up Thanks in advance. Some pics of the machine and my current progress.

These are decoupling capacitors, their main purpose is to filter out high frequency noise. The signal diode looking things are capacitors too, I've seen them mixed up with other types in the dram circuit . I guess they use everything they get their hands on and leave nothing to waste

Need more info and better shots of the keyboard to identify the type. As mentioned there are at least 5 different variants. I think you'll have an easier time replacing the entire keyboard than finding the right keycap.

Thanks, that's good to know. I was worried about excessive heat especially during the Aussie summer. Removing all the unnecessary chips ( mask roms, ttls & drams ) is going to help limit that.

Yeah sorry about that. I should have read further on. If it weren't for the monitor port on the PAL models I wouldn't have recommended it.

I'm a little confused here. He says in the video that he had to upgrade the machine's base memory from 16kb to 64kb to get Antonia to work?? I'm pretty sure I read somewhere in this thread that you don't need any dram installed in the Atari at all. That would make sense since the board has a replacement CPU and some ram already on it.

Ok I'm in for one. Just sent you payment!

My Amiga 500 got me into some trouble. I used to call BBSs for free Australia wide via a poorly setup diverter ( it would forward calls if you dialled quick enough ). I had a script which dialled up the diverter after hours and then quickly dialled the phone number of a BBS to get the free call. There were a number of us doing it and the phone company caught on. We all received threatening letters to stop abusing the diverter.

The 600xl has composite A/V if you own one of the PAL models.

Tough one but I'd probably go with a 600xl due to its small size and availability. The internal ram can easily be upgraded to 64kb or beyond.

I had this with my 800xl. I took my keyboard apart and found one of the small springs under the keys to be rusted on one end so I reversed the spring. Fixed my problem but I don't know if this is your problem.

Not so much an old manuals guy. I occasionally go through Zzap 64! and read all the game reviews, sometimes I download games to play on my c64. There were so many good titles I missed out on when I was in high school. The Internet and my old magazine collection gives me the opportunity to read the reviews and play those games again.

It would work in an open case but I don't know if that would work in all cases. RAM fails in many different ways. Say for example say you have a stuck low bit on the output of the bad chip, piggybacking a good chip would still drive the output low? Or you would have the stuck low bit superimposed over the good output? Best to remove all those DRAMs, install sockets and test them individually.

Nice job. The Borat photo at the end made me chuckle

The Multicades are great. They provide the closest experience you'll get to an original PCB due to re-implementation of the hardware in FPGA form. What I don't like is emulation in those cheap/underpowered boards, the audio quality is atrocious.My biggest issue is with the bootleggers who don't have any rights to distribute the rom images and are using MAME code in their products. I really question their ethics and I would never give them my money.

You could implement a driver in MESS, which has now been combined into MAME. It has support for virtually every chip out there used in arcades and also computer systems. This will definitely help once you start writing/testing the operating system as MAME comes with an excellent debugger.

I saw the last unit sell for $230 on eBay in completed listings, not a bad deal considering the long wait required for the next run.

Those DRAMs are sensitive to over voltage. A power supply failure or surge was most likely the cause. If you have no way of testing ram chips just replace the entire 8.

I stand corrected. It's the 40 pin 6503 (65C02) package in my Apple IIe. There is a 28 pin version but I've never heard of one used for the Apple II

I purchased a //e enhanced recently that appears to have the platinum motherboard. It has 1986 and ntsc international silkscreened on the main logic board. The CPU is a Rockwell 6503 which came in a 28 pin package. A low cost version of the 6502.

I think sound quality was still below par considering what the above mentioned sound chips could do. Other software houses were taking full advantage of the SID and POKEYs capabilities so I was generally disappointed when I finally got the chance to play some Br0derbund titles on my C=64. The Apple always played, felt and sounded better. But my opinion may be somewhat biased as I originally played those games at school on a //e system.