shoestring

Not too much. Games are just slightly more complicated now, more lines, more reels, inner reels, larger reel strips and multi features..etc I used to work in the industry once upon a time. Glad I'm no longer doing it

That's pretty much how modern commercial slot machines are implemented here. The reels are weighted by distribution of symbols and each reel stop is selected by a rng.

Partial failure in GTIA is not rare. My 65XE had no keyboard "tick, tick" sounds but video was perfect. I picked up a pair of nos ANTIC/GTIA chips off eBay for around 15 bucks, still plenty of those around. Those single wipe sockets are poor. Over time, they tend to lose their springiness and contact between the metal in the socket and the leg of the ic chip fails.

It's best not to continue troubleshooting with that power supply, even if it proves to be ok. They are known to fry a perfectly working machine when they fail. Your best case scenario is that your ingot is supplying less voltage than what is required. The LED may light up but less than 4.75v causes ttl logic to act up. Worst case scenario are multiple faults on the board due overvoltage. You may just have a bad component, at no fault of the supply but I would stop using it regardless. There should be someone in your area who can offer help and trouble shoot the machine with a good, known working power supply.

Can you get it to boot a disk ?

Always avoid the cheaper AC switching power adapters out there, especially ones that come with USB hubs. I've said it before. The real crappy stuff are house fires waiting to happen, they lack the proper filtering and are full of garbage quality capacitors that can short out or explode. If you value your life and your Atari, spend the extra bucks.

Nice. Mine took a lot of work to fix and the label was destroyed but at least I have a fully working system that I can mod. I still need to retrobrite the keys a little more though. I socketed the entire board also with high quality dual wipe sockets. It just makes future repairs and troubleshooting easier.

Dead machines can hide many faults. Take a picture or short video of the display you're getting now. That might help a little more than just a description.

Yes. That's perfect, those were used a lot in arcade games. The 1541 used 4 x 2114 static ram (UA/UB 2 and 3 ). The 1541-II used a single 6116/2128. You definitely want to check those if the light is flashing continuously. Also replace the 74LS14 ( UA1 ). You can find these at any electronics store. There are actually 2 x 6552s, why don't you swap them around and see if the symptoms/behavior change ?

You need an EPROM programmer to check the mask rom and read it in as a 2364. Most affordable programmers won't read those. My TopMax reads them though but it don't come cheap. You should also check the SRAM in the 1541. It will be a generic 6116 sram. They often go bad. I test these out of circuit using my TopMax. Piggy backing a known good 6116 can help identify a bad SRAM but not in all cases, especially if the chip is shorted internally. Yes the parts are fine. The 65c02 is the CMOS version and should be pin compatible with the standard NMOS 6502. The other chips are a little more difficult to test. But substituting the VIA and 6502 in another known working 1541 is a good way to troubleshoot those chips. A logic probe is also handy for identifying stuck and floating outputs on any of the above chips.

2364 / 2564 EPROMs are a little pricey due to their scarcity but you can sometimes find them cheap on eBay. You can opt for a standard 2764 8kx8 eprom but will need to buy or build a 2364 to 2764 adapter. http://blog.worldofjani.com/?p=757 I had to do something similar for the character rom. http://www.jammarcade.net/commodore-64-breadbin-repair-log-7-bad-characters-part-2/

Jack had no mercy when it came down to TI. I saw the 8 bit generation recently. Michael Tomczyk, Jack's assistant said in an interview that Commodore actually reverse engineered the TI-99/4a and worked out that they were losing money on their CPU ( TMS9900 ) and only making profits on their software and peripherals, Commodore was still making money on their c64. At that point Jack announced that they were cutting their peripheral costs and software in half and reducing the c64's price to $199

It's Atariage. Which is full of inflammatory threads like the "I don't really hate the Amiga, I'm just disgusted with the ads."

Also check the decoupling caps ( small yellow things ) near the chips, particularly the ones on each of the chip ram. These are are basically there to shunt the AC noise to ground. They can break very easily and if broken cause instability and the machine to crash. If you suspect the CIA chips swap them around and see if your symptoms change.

So then why do you get to use this argument and flip it around in your favour by saying that the IIgs was comparable to the c64 ? Especially since the IIgs isn't really a true Apple II system anyway, it's more of a hybrid Mac with Apple II compatibility. It's actually a much better system than the first Mac and Mac+ which is the reason I only make the comparison with the IIplus or IIe systems. It shares the same name but that's where the similarities end. [ if you don't consider the custom chip that contains all of the IIplus and IIe compatibility on a single chip ].

Compare it against the 2e which came out around the same time as the c64 and not the previous Apple 2 models. The 2gs was a 16 bit machine that was introduced after the ST and the Amiga. There was only one c64 but there were many Apple 2 variants over the years with various upgrades and enhancements to keep up with competition. There is a big difference between Apple IIs that were release in 1977 compared to models that were introduced in 1984-1986.

1. Games: C64. More titles than you can ever play entirely with the most active community still making games and demos today. 2. Graphics: C64. It had hardware sprites which meant you could move objects around the screen without having to constantly redraw what is underneath as they moved. Various screen modes [ Hires mode, multicolour mode, MIC mode, FLI mode..etc ] 3. Ease of use: Apple. Power supply was built in which meant no brick, long dangling chords or cables. It has a lovely keyboard and the machine is expandable via slots.Better durability and reliability. Disk II system was much better and faster than the 1541. 4. Price: C64. Best bang for the buck, no question. The computer for the masses not the classes 5. Basic: Apple 2: Commodore's basic [ which was purchased from Microsoft ] was never great until the c128 was released. I learnt to program on the Apple and struggled to do anything useful on the Commodore even though I owned one and typed in many listings and they ran. I also loved the built in machine language monitor on the later Apple models at school which I used extensively and learnt how to program the 6502, this taught me a lot about hardware and how computers worked. To do the same on Commodore meant you needed a freeze frame or action replay cartridge [ had a machine language monitor built in ] this cost a lot of money that I didn't have back in the day. Business: Apple. The Commodore had business software and an 80 column cartridge available but I think most later Apple 2s shipped with them built in ( Extended 80 column card ) and they already had a vast array of business software available that were lacking on the c64. Apple had Visicalc before any other platform which really helped boost Apple sales in the beginning and establish it as the more serious computer. Lets face it, if you bought a c64 you didn't do so to run Visicalc or other business software I think the only market the c64 didn't have the Apple 2 had was the educational market hence the reason we saw them so much in schools. Regarding the 2gs, this was released almost 4 years after the C64. For a fair comparison we should just consider Apple 2e, ZX Spectrum and the C64 which were all released roughly around the same time. The 2gs has amazing sound, this doesn't surprise me in the least since the same guy who designed SID chip in the C64 designed the sound chip in the 2gs. SID was actually a hybrid digital/analog synthesizer chip whilst the Ensoniq 5503 in the 2gs was a true digital wavetable synth, the technology was completely different.

A sign of a bad capacitor will be buldging outward at the top or leaking, sometimes it's not so obvious. There's not that many electrolyitc caps in the A500 so the task should be relatively easy.

The Amiga was fantastic. It didn't need ads. That machine sold itself and was the talk in my school. Everyone at my school who owned an 8bit machine upgraded to an Amiga except for the Apple 2 guys of course.

Chip creep perhaps. I remember having to reseat the 68000 at least once or twice a year.

I sold an Apple //e ( enhanced ) in great condition for less than $300 AUD recently. So there are definitely good ones out there if you're patient enough to wait for the right one.

I'll open up my 600xl and take a look. I'm a little confused by where the 4k7 resistor is supposed to go. So maybe someone else can chime in and clear things up. The 600xl schematics already show a resistor between DATAOUT and +5v @ R76 but the sio2sd site goes on to say between pin 1 and 5 of SIO connector ?. Pin 5 is DATAOUT but pin 1 is the clock input, pin 10 appears to be +5v.

C77 and C78 are actually 1nf capacitors. .001uf = 1nf In the 600xl the capacitor locations which are tied between datain/dataout and ground are C89 and c90.

I used a mixed solution of laundry booster and water and submerged the parts for a few hours in the sun. The keys are harder to do but it does work. I did not do the bottom of the case fearing that the sticker on the bottom would be destroyed. At some point I'm going to re-do the keys to even out the results. http://members.iinet.net.au/~davem2/overclock/Retrobrite.html

Probably work in a single wipe or machined pin socket. But try getting a thin wire to stay in a dual wipe socket. I hate it when I break a leg but it's relatively easy to solder a donor leg on and it ends up being just as durable...any trick to save money