Atari-Forum

Then there was Robson and his awesome color mod - I recall he just spray painted the keycaps and then used some sort of foil for letters: http://www.tercsirobi.byethost14.com/index.php?p=1_7 I have asked him for details, and I hope he doesn't mind if I just quote his words: "I bought white matt...

I recall Alison tried that with her ST mouse and ended up with a pile of plastic, as the Atari plastic was much more sensitive to heat and the mouse melted down. I'd try it with just a few keys you don't care about... EDIT: just found it: http://atari-forum.com/viewtopic.php?f=15&t=14047&p=1...

The other way would be to use a SCSI drive in your Megafile. As I recall, SH204 used ACSI-to-SCSI adapter and then SCSI-to-MFM adapter and MFM drive. Those adapters appear on eBay now and then.

Although more expensive, I found the safest method is to immerse the whole machine in hydrogen peroxide. I buy 1 gallon of 40% concentrate for $40 and mix it 8:1 with water ending up with 5% solution. It never dries out this way hence safe, and takes about a day or two of slightly cloudy days (I fi...

Wouldn't HCT work as well? When seeing people using LS, I feel so retro...

I still might have one spare PCB. It needs minor modification, but it works relatively well :) Send me a PM if you're interested. Hi Kubik, I PMd you. Hi again Kubik, Have you changed your mind re the PCB you mentioned? TeX38 I'm sorry, I have no clue what do you mean :) I have answered your PM bac...

Sorry to hear that, but at least you had some fun I feel your pain, I am struggling with RTC on ST and it's the same mystery to me as the 2chip TOS is to you

Hmm, honestly, I am out of ideas. It's most likely something pretty basic, but without having the board at hand, I can't say what. If I was in this situation, I'd try a logic analyzer and see what's going on and try to guess what are the first few reads from those EPROMs. (I've just found out the $5...

Yeah, I am positive it is because I am mixing it wrong. I have two kinds, and failed with both. The molding plastic is awesome. I used it to cover up my solder job on the TOS switcher on my 1040STe and the 030/060 switch on the Falcon. Worked great. Poor man's 3D printing? You'd better RTFM on thos...

Good hint, thanks! As for the epoxy problem - are you sure you're mixing it properly? Some epoxies use 1:1 ratio, but some don't. If you're sure you've got the ratio right, use a bit less of the hardener - it's difficult to guess the amount right if you're mixing just two tiny drops of it :) Gooey c...

I'd guess implementing other cores should be possible, however, this isn't about having thousands of cores - that's what Mist (or ZX Uno) is for. This is a new ZX Spectrum, with modern design, modern technology, modern features, and yet backward compatible as much as possible, including HW compatibi...

farvardin wrote:very nice, but expensive as hell!

The price was supposed to be exactly the same as ZX Spectrum when released. Actually, due to inflation, it's much cheaper - those 175GPB in prices of 1982 would correspond to something like 500 GPB nowadays.

I believe it's straight 1:1 cable, nothing special, you could easily build it yourself.

Glue has always the same main number. What you think is glue in your 520 is actually MMU :) I don't think SECAM has anything to do with it, you would still get lores picture, just B/W. It's more like a connector problem, monitor detection problem, or your monitor doesn't do 15kHz. EDIT: Now when I a...

I believe 1.04 is the highest you can run on this, but 1.02 is good enough. There are also some patched TOSes, EmuTOS etc, but I'd stay with the ones you have, at least until you can confirm the thing works. If I am not mistaken, EPROMs are not pin-to-pin compatible with TOS ROM chips. The monitor c...

My recommendations for tools are above :) I've realized one thing that wasn't explicitly said. If I am not mistaken, the address signals on EPROMs are 'shifted' by one - that means that A15 of EPROM is connected to A16 of CPU, A16 of EPROM is connected to A17 of CPU. That one pulse you're getting co...

As a first check, I'd verify the EPROMs are getting /CE signals, because at the moment it looks like the system doesn't start at all. It would be great if your probe was able to count the pulses as well, that way we could determine what's going on. I love my Superprobe, it helped me a lot many times...

Does the floppy do the same sound when you just reset the computer? What kind of diagnostic tools do you have?

Yep, I have added RTCPAL (or something similar to it). I can see the chip select signal working fine, and I can read an write registers. I didn't do any other test besides the diag cart, because it's just a bare 520ST mainboard sitting on my desk, no floppy and stuff. The goal is to have a small PCB...

Did you see any problems designing and testing those? I am basically about to do the same, but for 4MB SIMMs (for old MACs, SoundBlasters etc), and I wonder if there's something I should be aware of.

Yeah, I could go with a off the shelf PSU. But I'd rather build stuff myself and know its works properly. Even so, people could do that themselves anyway. I fully understand that, I am like that myself :) However, such a kit using off the shelf PSU might be interesting for different class of custom...

One way to keep the price down would be to use standard PSU and just desing a case and cabling around it. If I paid something for Atari PSU, it would be for the look and feel, not the innards. Meanwell PSUs are pretty good and very reasonably priced - their 66W one (5V/12V) costs around twenty quids...

TeX38 wrote:In fact, if anyone reading this subject has one hanging around unused I would love to hear from them.
I would be interested in just the bare board if available.

I still might have one spare PCB. It needs minor modification, but it works relatively well Send me a PM if you're interested.

Folks, does someone have working Mega and diag cart at hand? I have added the Mega RTC chip (Ricoh RP5C15) to my 520ST. I am reasonably sure it works, because I can see registers at addresses FFFC21 and above, I can see the second counter incrementing, and I can change values of most registers. Howe...

I think it actually needs 5V only if you don't need to boot from floppy. To check whether the board has survived the PSU failure is 5V sufficient, even a 5V wall wart should do (like one used for active USB hubs, providing 5V / 2A). That PSU failure was 95% caused by failed caps. You can try replaci...