What to do with 600XL?

[yorgle]

I recently acquired a 600xl as part of a AtariWriter package deal from ebay (needed the 1027 printer for my 800xl setup). The 600 doesn't work but I'm thinking I'd like to fix it. I've already swapped its keyboard into my 800xl but feel kinda bad just having the poor 600 sitting here, dead. It doesn't power up at all- the red LED doesn't even come on. Where should I start?

[Urchlay]

I recently acquired a 600xl ... It doesn't power up at all- the red LED doesn't even come on. Where should I start?

 

First step is to try a known good power supply, of course... the one from your 800XL.

 

The red LED is part of the keyboard... I assume you mean the LED didn't come on when you still had a keyboard in the 600XL?

 

Have you tried hooking the 600XL up to a TV or monitor, to see if you get any sort of video at all? Even a totally black or green picture means something different from absolutely NO signal... Though if the LED doesn't light up, you probably aren't getting any video either.

 

If that's the case, and the power supply is definitely good, you'll want to check the power switch. You need a multimeter... with the power supply *disconnected* and the switch in the off position, check the resistance across the switch. It should be open (infinite resistance). Now close the switch... you should read 0 ohms (a short). If not, replace the power switch, see if that fixes it.

 

Next thing you want to do: get hold of a schematic from http://jsobola.republika.pl/schematy.htm, it's in Polish, but look for "600xl.zip". The actual schematic has very little text, so you should be OK if you don't speak Polish.

 

Have a look at 600XL_8.PCX, which is the power section... In the upper left corner is the power switch. With the power supply connected and the switch on, see if you have +5 volts between point "5A" and ground, and between "5B" and ground. Basically, look for L1, L2, L3, and L4 on the board (they're inductors, aka coils, kind of oval-shaped components) and check for +5V on either side of each one. Also you can check resistance across each coil: it should be almost a short (near 0 ohms). If any of the coils read more than a few ohms, or if one side of a coil reads +5V and the other reads 0 volts, they're probably the culprit... also check the various capacitors (C1 through C16), which should basically appear as an open circuit with the meter in the "ohms" setting. If any of the caps are reading 0 ohms, that's very bad (if that's the case, your power supply might melt).

 

If the coils and caps check out OK, you might look at the schematic and find the pins on the various chips labelled VCC, and see if you have +5V between those and ground.

 

All the above assumes a good bit of knowledge on your part (e.g. how chip pins are numbered)... If I'm going too fast, feel free to ask questions... I'm not really an electronics expert, but I'm willing to help with anything I can help with.

[yorgle]

Thanks for the great reply. I've printed out your suggestions and will go at it this weekend to see if I can get it working again. I don't really have a use for this computer, but I just can't stand to have something laying here that doesn't work. If anyone here wants it, let me know. As long as it is going to a good home, it's free for the taking (except for shipping, of course).

[Urchlay]

Thanks for the great reply. I've printed out your suggestions and will go at it this weekend to see if I can get it working again. I don't really have a use for this computer, but I just can't stand to have something laying here that doesn't work. If anyone here wants it, let me know. As long as it is going to a good home, it's free for the taking (except for shipping, of course).

 

Have a go at fixing it before you get rid of it...

 

Normally I'd jump all over a free "parts" 600XL, but at the moment I'm still unpacking from moving last week... my new place is maybe half the size of the old place, so there's not even room for all the stuff I have now

[jaybird3rd]

If you can't get it working and decide to get rid of it, at least save the chips off the motherboard. They're not being made anymore, after all, and could be used to repair another 8-bit computer down the road.

[+orpheuswaking]

If you really want to pass it along, I would be happy to take it off your hands

[Scream And Fly]

The 600XL is an awesome machine. They are so small, and expanded, are as good as any other.

[yorgle]

If you really want to pass it along, I would be happy to take it off your hands

[yorgle]

If you really want to pass it along, I would be happy to take it off your hands

 

Sorry 'bout the double post. Since you're the first to ask, it's yours for the cost of shipping. PM me your address and I'll let you know how much it will cost to ship. I was going to try to fix it, but just don't have the time.

Edited August 5, 2007 by yorgle

[yorgle]

Hey, I got it working! I had scrounged the 600's keyboard for my 800xl and decided to stick the old 800xl keyboard into the 600's case just to keep everything together. Just for kicks, plugged it in, flipped the switch and HEY, IT NOW WORKS! I know I said I'd give it away, but I've changed my mind. I think I'll keep it here at my office to play with.

[+Guitarman]

Hey, I got it working! I had scrounged the 600's keyboard for my 800xl and decided to stick the old 800xl keyboard into the 600's case just to keep everything together. Just for kicks, plugged it in, flipped the switch and HEY, IT NOW WORKS! I know I said I'd give it away, but I've changed my mind. I think I'll keep it here at my office to play with.

 

I love those kind of fixes!!!

[yorgle]

I spoke too soon. Apparently some of the ram is bad. If I boot to BASIC, I can get the READY prompt, but it locks up a few seconds after that. If I turn it on holding the OPTION key, I can get to the test menu. I ran the MEMORY TEST and the ROM test goes ok, but the RAM test starts showing two green blocks followed by four red blocks then it locks up. Anyone know the number of the RAM chips?

[guus.assmann]

I spoke too soon. Apparently some of the ram is bad. If I boot to BASIC, I can get the READY prompt, but it locks up a few seconds after that. If I turn it on holding the OPTION key, I can get to the test menu. I ran the MEMORY TEST and the ROM test goes ok, but the RAM test starts showing two green blocks followed by four red blocks then it locks up. Anyone know the number of the RAM chips?

The Ram chips are 4464. (TMS4464, KM4464)

These are 16K x 4 Bits dynamic Rams.

Use 44256 instead. Those are 64K x 4. With only few modifications, some wires and pins disconnected, it will be 64K.

And then it's the same as a 800XL.

The chips may be found on video-card from quite old PC's, even the 486-es.

 

If you need more info on the mods, let me know.

 

BR/

Guus

 

P.S. It may also be a bad CPU, with a heat problem. Does it always go bad once two blocks are green?

Edited August 8, 2007 by guus.assmann

[yorgle]

I spoke too soon. Apparently some of the ram is bad. If I boot to BASIC, I can get the READY prompt, but it locks up a few seconds after that. If I turn it on holding the OPTION key, I can get to the test menu. I ran the MEMORY TEST and the ROM test goes ok, but the RAM test starts showing two green blocks followed by four red blocks then it locks up. Anyone know the number of the RAM chips?

The Ram chips are 4464. (TMS4464, KM4464)

These are 16K x 4 Bits dynamic Rams.

Use 44256 instead. Those are 64K x 4. With only few modifications, some wires and pins disconnected, it will be 64K.

And then it's the same as a 800XL.

The chips may be found on video-card from quite old PC's, even the 486-es.

 

If you need more info on the mods, let me know.

 

BR/

Guus

 

P.S. It may also be a bad CPU, with a heat problem. Does it always go bad once two blocks are green?

 

I get different effects each time I turn it on- sometimes it comes up with a blank red screen, sometimes it will boot to the READY prompt but then lock up. Sometimes it will simply show a black screen. Even when I get the READY prompt, I can only enter a few lines of program before the wierdness starts.

 

Are you sure the RAMs are supposed to be 4464's? The ones in the computer now are 4416's. Maybe that's the problem. I have a bunch of 4164's but they're only 16 pins. The sockets on the board are 18 pins.

[puppetmark]

I spoke too soon. Apparently some of the ram is bad. If I boot to BASIC, I can get the READY prompt, but it locks up a few seconds after that. If I turn it on holding the OPTION key, I can get to the test menu. I ran the MEMORY TEST and the ROM test goes ok, but the RAM test starts showing two green blocks followed by four red blocks then it locks up. Anyone know the number of the RAM chips?

The Ram chips are 4464. (TMS4464, KM4464)

These are 16K x 4 Bits dynamic Rams.

Use 44256 instead. Those are 64K x 4. With only few modifications, some wires and pins disconnected, it will be 64K.

And then it's the same as a 800XL.

The chips may be found on video-card from quite old PC's, even the 486-es.

 

If you need more info on the mods, let me know.

 

BR/

Guus

 

P.S. It may also be a bad CPU, with a heat problem. Does it always go bad once two blocks are green?

 

I get different effects each time I turn it on- sometimes it comes up with a blank red screen, sometimes it will boot to the READY prompt but then lock up. Sometimes it will simply show a black screen. Even when I get the READY prompt, I can only enter a few lines of program before the wierdness starts.

 

Are you sure the RAMs are supposed to be 4464's? The ones in the computer now are 4416's. Maybe that's the problem. I have a bunch of 4164's but they're only 16 pins. The sockets on the board are 18 pins.

 

The stock Ram chips in a 600XL are 4416. they are 16K x 4. The 4164 chips you have are 64k x 1 and won't work. you can use 4464K or 44256K ram chips if you want to upgrade the 600XL to 64KB.

[re-atari]

The Ram chips are 4464. (TMS4464, KM4464)

These are 16K x 4 Bits dynamic Rams.

Use 44256 instead. Those are 64K x 4. With only few modifications, some wires and pins disconnected, it will be 64K.

And then it's the same as a 800XL.

 

@ Guus: I presume you are doing some other projects and answering this question all at the same time, as you have some of the info mixed up

 

@All: Guus is the original designer of the NL 256Kb memory upgrade, former employee of Atari Benelux and long time A8 electronics expert. When it comes to the A8 architecture he definitely knows what he's talking about. His reply goes to show that to err is human, a slip of the tongue happens all of us every now and then.

 

@ Yorgle: The original 600XL uses 2 pcs 4416 DRAM (16kbit*4) giving it 16Kb. With some added wiring and effort it can be upgraded into a 64Kb machine using 2 pcs 4464 DRAM's (64kbit*4). The 4416 and 4464 are largely pin-compatible. IIRC Guus posted the correct how-to about a month or so ago. Installing 44256's DRAM's (256kbit*4) to build a 256Kb computer will require a bit more, both in wiring, 74LS's and effort.

 

re-atari

[yorgle]

The Ram chips are 4464. (TMS4464, KM4464)

These are 16K x 4 Bits dynamic Rams.

Use 44256 instead. Those are 64K x 4. With only few modifications, some wires and pins disconnected, it will be 64K.

And then it's the same as a 800XL.

 

@ Guus: I presume you are doing some other projects and answering this question all at the same time, as you have some of the info mixed up

 

@All: Guus is the original designer of the NL 256Kb memory upgrade, former employee of Atari Benelux and long time A8 electronics expert. When it comes to the A8 architecture he definitely knows what he's talking about. His reply goes to show that to err is human, a slip of the tongue happens all of us every now and then.

 

@ Yorgle: The original 600XL uses 2 pcs 4416 DRAM (16kbit*4) giving it 16Kb. With some added wiring and effort it can be upgraded into a 64Kb machine using 2 pcs 4464 DRAM's (64kbit*4). The 4416 and 4464 are largely pin-compatible. IIRC Guus posted the correct how-to about a month or so ago. Installing 44256's DRAM's (256kbit*4) to build a 256Kb computer will require a bit more, both in wiring, 74LS's and effort.

 

re-atari

 

Thanks for the clarification.

[Urchlay]

If you do come across some 4464's, you should know that you can replace your suspected-bad 4416's with them, without doing the rest of the 64K upgrade, and they'll function as though they were 16K chips. If this fixes the problem, you can do the rest of the 64K upgrade whenever you're ready, or just use it as a 16K machine. I've done a 600XL 64K upgrade, and it's pretty easy (replace the 2 RAM chips, solder 3 wires).

 

One easy thing you might try to do before swapping the RAM: reseat all the socketed chips. It's possible that some of them have worked their way loose over many years of expansion/contraction caused by temperature changes (especially if it was stored in an attic in a hot climate).

 

Another easy thing you could try: swap the two 4416's. It's at least possible this could help...

 

You said you can type a few lines of BASIC before weird things start to happen... what sort of weird things? Does it always do the same thing? Does it just freeze, or does the display turn to garbage, or does it just turn a solid color? Also... does it do this if you just boot to a READY prompt and let it sit for a while, or only if you actually try to use it?

[yorgle]

If you do come across some 4464's, you should know that you can replace your suspected-bad 4416's with them, without doing the rest of the 64K upgrade, and they'll function as though they were 16K chips. If this fixes the problem, you can do the rest of the 64K upgrade whenever you're ready, or just use it as a 16K machine. I've done a 600XL 64K upgrade, and it's pretty easy (replace the 2 RAM chips, solder 3 wires).

 

One easy thing you might try to do before swapping the RAM: reseat all the socketed chips. It's possible that some of them have worked their way loose over many years of expansion/contraction caused by temperature changes (especially if it was stored in an attic in a hot climate).

 

Another easy thing you could try: swap the two 4416's. It's at least possible this could help...

 

You said you can type a few lines of BASIC before weird things start to happen... what sort of weird things? Does it always do the same thing? Does it just freeze, or does the display turn to garbage, or does it just turn a solid color? Also... does it do this if you just boot to a READY prompt and let it sit for a while, or only if you actually try to use it?

 

Wierd= random characters appear scattered across the screen. Pressing RESET results in a black screen. I did switch the two 4416's around to see if that made a difference, but it didn't. I'll try reseting all the chips (everything is socketed). Thanks on the 4464 tip- I was wondering if I could do just that- I don't really need to get 64k right now, I just want to get the thing working.

[jaybird3rd]

Wierd= random characters appear scattered across the screen. Pressing RESET results in a black screen. I did switch the two 4416's around to see if that made a difference, but it didn't. I'll try reseting all the chips (everything is socketed). Thanks on the 4464 tip- I was wondering if I could do just that- I don't really need to get 64k right now, I just want to get the thing working.

If you're simply looking to repair your bad RAM without doing the upgrade, I've got a pair of good 4416 chips left over from one of my upgraded 600XL machines that I could probably let you have for the cost of shipping. PM me if you're interested.

 

I would, of course, recommend that you do the upgrade eventually. It's trivially easy if you have the right RAM (three extra wires and on or two cut traces, if I remember correctly), and it will make your 600XL a lot more useful.

[guus.assmann]

The Ram chips are 4464. (TMS4464, KM4464)

These are 16K x 4 Bits dynamic Rams.

Use 44256 instead. Those are 64K x 4. With only few modifications, some wires and pins disconnected, it will be 64K.

And then it's the same as a 800XL.

 

@ Guus: I presume you are doing some other projects and answering this question all at the same time, as you have some of the info mixed up

 

@All: Guus is the original designer of the NL 256Kb memory upgrade, former employee of Atari Benelux and long time A8 electronics expert. When it comes to the A8 architecture he definitely knows what he's talking about. His reply goes to show that to err is human, a slip of the tongue happens all of us every now and then.

 

@ Yorgle: The original 600XL uses 2 pcs 4416 DRAM (16kbit*4) giving it 16Kb. With some added wiring and effort it can be upgraded into a 64Kb machine using 2 pcs 4464 DRAM's (64kbit*4). The 4416 and 4464 are largely pin-compatible. IIRC Guus posted the correct how-to about a month or so ago. Installing 44256's DRAM's (256kbit*4) to build a 256Kb computer will require a bit more, both in wiring, 74LS's and effort.

 

re-atari

 

Thanks for the clarification.

Yep, Mixed up some IC numbers. (But not the functions) Sorry.....

If you can't get the chips, I do have some to spare. (Also, the rebuild to 64K is very simple indeed)

Most of the time, if the Ram chips are bad, they also get quite warm.

I mean they get too hot to keep holding them without wishing you had not.

The irregular behavoiur may also be caused by simple bad contacts.

Remove all chips from the sockets (one by one) and push them back. That may cure the problem.

BR/

Guus

[yorgle]

This is madness!!! I only got this blasted thing because I wanted the 1027 it came with, but now I'm obsessed with getting it working. I've got ram chips coming in the mail and I've wasted a whole afternoon pulling and resetting chips, switching it on and off again- each time getting a variety of wierd results or simply blank, red screens. Now I'm wasting time reading up on 64k ram and monitor port upgrades thinking "cool, I can make it just like an 800xl." I'VE ALREADY GOT A PERFECTLY GOOD 800XL SYSTEM!!!. Why can't I just let this thing die... Is there a cure for this type of insanity?

[mimo]

NOPE, see signature, I only wanted an 800 xl to relive my youth ( bought it in November last year)

now I have 3 800 XL's, 2 400's, ,1200 XL, 2 2600's, 3 7800's, 2 5200's etc etc etc

[Beetle]

Hopeless. Atari virus is incurable so far. You can take a year-long break,

but after that it will get you even harder.

Just like Mimo i just wanted to play a bit with my youth memories.

Then i did some work in my hobby room, which gave me more workplace.

So i decided to put one Atari setup on the desk which was my 800XL.

 

Look my signature to see what happened since i joined here March '06.

Edited August 10, 2007 by Beetle

[yorgle]

Hopeless. Atari virus is incurable so far. You can take a year-long break,

but after that it will get you even harder.

Just like Mimo i just wanted to play a bit with my youth memories.

Then i did some work in my hobby room, which gave me more workplace.

So i decided to put one Atari setup on the desk which was my 800XL.

 

Look my signature to see what happened since i joined here March '06.

 

So I should just embrace it? Let it control me? No, I say! I won't do it!! I have free will. I can choose. Who am I kidding. I'll report back after I see what the new RAM chips do.