guus.assmann

This switch has 2 contacts that are insulated from each-other. Both "switch-decks" are separated by extra insulation. That's the black plastic that's visable vertically between the pins. There is not input or output. Looking at your picture, the two pins on either side of the "bridge" in the middle will be connected or not, depending on the position of the switch. So a connection will be between the pins vertically, on either side of the bridge. Or in other words, connect the power input to 2 horizontally placed pins. Connect the wires to the power supply to the other pins. Normally, an Ohm-meter will tell you just fine. And you could test with a small battery and a light-bulb, or motor. So low voltage and only 2 pins = half the switch. That way it cannot go wrong. And now for the disclaimer: If still in doubt, ask for help. But to someone who's physically available. :-) BR/ Guus

Hello, Why not socket the LMC1992 in the 1040STE? Then you can use that to test the other IC's. Of course you need to be able to not destroy the 1040STE. And also, put the suspects in the 1040 and not the LMC1992 from that in the TT. If the TT is the "killer" it won't be able to get the other chip. It's highly unlikely that the 1040STE will be killed by a broken LMC. On the TT, check all spots and traces that may have been in contact with the shielding. And one more thing. Check the metal standoffs of the power supply. They can short out tracks. Specially the one on the left/middle may touch a capacitor. (I mean the metal that's away from the back of the computer.) BR/ Guus

Hello pixelmischief, You're missing the pin, obviously. :-) Now seriously, it seems likely that the pin is missing for a reason. It may have been a reversing safeguard. To be sure, you'd need to verify with the original power supply. If it has no wire on that position it's clear. Does it look like the pin is broken of? Can't see that on the picture. If there's a piece of pin left, check for continuity between the pin-part and the last 3 pins of the connector. I'm writing this, without having a look in a Mega STE. I do have one, but it's quite some work to get it and open it up. Maybe Frank Lucas has one available that's also opened up and still complete. BR/ Guus Assmann

Hello, Some lines? I hope the attachment will do much better. As a Chines proverb says: One picture is better than 1000 words. NB: TT and STE-pwer supplies are identical. BR/ Guus TT_Power_Wires.PDF

@pixelmischief Just now I had a look at the switch. The type (building form) will do just fine. It sort of looks like the one used in the original power suppply. But you should take one that's rated for 125V-AC. This rating is mainly for the fact that the connections should not be too close. There's some rules for that. In Netherlands (230V-50Hz) the minimum distance has to be 5mm (about 0,2") This is called "creep distance" Peronally, I'd choose a double-pole switch and make sure to use a 3 lead-connection. That is with protective earth connection. BR/ Guus

It may also be dirt, bad solder joints or solder "Whiskers". Clean it all and resolder as much as you can.

For the Mouse, have a look at the traces from the connector into the keyboard. That's where I would expect damage / bad contacts. And for the Tos-Roms. It should be fairly easy to get another Tos for the machine. Have a (Google) look for Atari TT: Storm, Thunder and Lightning. These are names for boards that give the TT a USB interface, a CF interface and more TT-Fastram. It needs a patched Tos and the Roms are included. BR/ Guus

Hello, Thanks for the presentation and the hard work behind it. And of course I'm curiuos about the price. Please keep up the good work :-) BR/ Guus

For 1.44 MB to work, there's also a Gal that needs to be the right revision. If not, it won't work either. If I'm not mistaken, the one you need is in this .zip However I'm not sure which one to get. And I don't have source code. I did replace that one in my computer as well and also placed the FPU and Gal with that. BR/ Guus GAL.zip

If the capacitors are removed and the resistors and possible coils are bridged, the I/O will be faster. However, the computer will not pass the EMC test. That may cause problems in some case. It may cause RF interference. The 68B21 has some higher drive capabilities. That can also cause more RF. Not always a big deal really. BR/ Guus

Hello, The circuits in the Atari are all 5V. So is the RTC. But it will remain working fine at a lower voltage. 4,5V is well within the safe range. Just make sure that the batteries will not be emptied and start leaking. That would make a terrible mess and now you'll get 3 instead of 1. You might consider putting in Eneloop cells. Then you'll get about 3,6V. BR/ Guus

I own at least 2 of those boards, one with original box and documentation. They were designed for the Mega ST and have this size, so the can be securely be mounted in the computer. There's a couple of standoffs at the end of the board, away from the connector. Also there's some metal shielding. There's a 16Mhz oscillator on the board. I've put a socket in and tested with higher frequencies. Above about 24Mhz there's not much improvement anymore. (Gembench test) The speed is determined mainly by the data transfer between CPU and FPU. BR/ Guus

Sorry, I've only used the board a couple of times using Dos. So I'm not sure about any windows version. BR/ Guus

Hello, Yes, you're right that there's a difference. I'm not sure if the "simpler" version will work. Maybe some specs can be found for the board? (Or the readme file with the software) Both the one in my Mega STE and the one that's not mounted do have an FPU socket. And I also have 1 without the FPU socket. That one is also not mounted. BR/ Guus

Hello, I own a Mega STE with an AT-Speed in it. It does contain a 286 and also has a Chrystal on the PCB. (32Mhz is engraved) And the Atari does run at 16Mhz. Also, there does exist an adapter from the PLCC 68000 to a Dip 64 socket that's specially made for an 286 PCB. I don't have the schematics for either card. The Adapter I've just seen is made by GE-Soft. My Mega STE works well, until I move it between rooms. As long as I don't do that and let it sit in it's own place, it's working happily. BR/ Guus

Have a good look at the Gotek documentation. There's a possibillity to use pin 2 for disk-change signal. That may be of use. (Have not tried it myself...) BR/ Guus

There's an adapter board to interface between the PLCC socket and the DIL socket. However that may be hard to get and can cause contact problems. I have to reseat mine every once in a while. So yes, it will function just fine in the MegaSTE, also if that's run at 16Mhz. The 80286 has it's own clock.... BR/ Guus

Hello, The fact that you succeded is proof that you did it right. And the price for the chips is quite good I think. In future, also look at the speed of the chips. 150nS is mostly good enough. (On 8Mhz system 200nS will also do) On a TT you may want to use 120nS. Erasing depends on the light source. Just experiment with shorter times. If you test before programming, it's ok. One very important thing for erasing Eproms. Make sure they're in conducting foam,all pins must be electrically connected. Failing to do so may destroy an Eprom. Especially the older ones like 2716 or 2732. The even older 2708 will definitivly not survive if pins are not connected. I've learned that in the time that an Eprom costs FL 150 (Current equivalent is $ 150). They were not my Eproms, my manager killed them and I found out why. BR/ Guus

What's the speed of the Eproms? 120nS would be ok. Slower may cause problems. BR/ Guus

Hello, That's a matter of taste. Personally, I like GFA Basic better. (Has lots of examples as well). BR/ Guus

Hello Bikerbob, It is very possible that the revision of the test cartridge is the problem and not the hardware itself. I've had this issue, until I used another (multi) testcartridge. It might need a test cable or another fixture to pass this timing test. Does the testcartridge start the menu? Maybe after hitting the space key? You should be able to do all other tests. However, I cannot tell you what revision to use. (I'm not home at the moment) BR/ Guus

Mostly, if you heat up the label, the glue will become soft and the label will come of more easy.

Hello, I have made a PCB, many years ago, that made it possible to use a 65C02 in the XL's or XE's. And the XL7 is already in this forum, look at the attachments I put in. Schematics and source code are there. Just needs some sorting out. There's "logic" in the file names. BR/ Guus

Hello, Technically a bit of topic. And I've made the assumption that Bob has no objections, as he offered to look for some stuff. A while ago, Bob has done some significant speedup of a 1200XL. And I've tested it on the 600XL, 800XL and 130XE. It worked on all boards. ! But I don't recall ecactly what's what. And I also tried to get it to work at 14Mhz and include the OS and Basic-Roms and XE-GS ones as fast Rom. It didn't work and I should have bought a logic analyser to get it to work. Never done that or spend enough time.... BR/ Guus Speedy816_Bob_Wooley.zip PCBS.zip SCH.zip

Politicians discuss about laws and this changes these laws. So they think that discussing the rules and laws of nature can have the same effect. They generally lack the intelligence / knowledge / interest to understand it's not possible.