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Questions about 1200xl Mods

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I'm kind of excited I just finished a small mod on my 1200xl and all went well. I know it is the easy one where you remove R63 and solder in a jumper to get 5v to the SIO port.

 

Now I really want to do the "ClearPic 2002" http://www.retrobits.net/atari/clearpic.shtml mod but I have a few questions.

 

*Where is the best place to get the parts? I went to Radio Shack today and they only had 2 out of the 6 parts.

*I was also asked what wattage I needed I would assume the lowest wattage but I'm not sure. As you can tell I know very little about electronics.

 

*I am also unclear in the last step where you have to solder a wire from junction R27 and C61? I see they are side by side does this mean solder a wire to both top leads (across both leads) to J2-5?

 

*Does anyone have a picture of the last step R27 and C16 to J2-5?

 

**Oh almost forgot how or what is the best way to remove the solder from the holes. I have tried a paper clip and safety pin both not very easy or neat.

 

Thanks,

Mark

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Low value components ~ 3-5 Watts should be fine.

 

I did one of the Supervid mods on my 800XL, fairly sure I just used desoldering braid when removing components. Getting every last bit out shouldn't be too critical, just ensure you don't end up with any bridged joints or damage any traces.

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*Where is the best place to get the parts? I went to Radio Shack today and they only had 2 out of the 6 parts.

 

I get all my resistors caps & diodes on Radioshack.com. They'll deliver to the closest store to you or to your home - I've done both depending on which will be quicker.

 

There are plenty of other sources for electronics on the internet.

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Use 1/4 watt carbon (film) resistors.

 

The 'top' of C61 and R27 are connected together with a copper trace. Run the wire from either one to J2. (look at the bottom of the board and you can see the trace)

 

Solder braid is the best way to clear the holes. Cheapest, anyway. R/S has a de-soldering iron that sometimes works better if you have a lot of holes to do.

 

Hope it works well for you.

 

Bob

 

 

 

I'm kind of excited I just finished a small mod on my 1200xl and all went well. I know it is the easy one where you remove R63 and solder in a jumper to get 5v to the SIO port.

 

Now I really want to do the "ClearPic 2002" http://www.retrobits.net/atari/clearpic.shtml mod but I have a few questions.

 

*Where is the best place to get the parts? I went to Radio Shack today and they only had 2 out of the 6 parts.

*I was also asked what wattage I needed I would assume the lowest wattage but I'm not sure. As you can tell I know very little about electronics.

 

*I am also unclear in the last step where you have to solder a wire from junction R27 and C61? I see they are side by side does this mean solder a wire to both top leads (across both leads) to J2-5?

 

*Does anyone have a picture of the last step R27 and C16 to J2-5?

 

**Oh almost forgot how or what is the best way to remove the solder from the holes. I have tried a paper clip and safety pin both not very easy or neat.

 

Thanks,

Mark

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Garry: 3W resistors are a bit bulky ;) not to mention 5W ones, standard size resistors have 1/6-1/8W

 

as fot the wire Bob mentions i would go for shielded type of wire (one wire in a copper shield) to reduce the noise that might get into unshielded wire as it goes under the board

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*Where is the best place to get the parts? I went to Radio Shack today and they only had 2 out of the 6 parts.

 

I get all my resistors caps & diodes on Radioshack.com. They'll deliver to the closest store to you or to your home - I've done both depending on which will be quicker.

 

There are plenty of other sources for electronics on the internet.

I get electronic components through www.mouser.com and www.digikey.com. Mouser gets a lot more of my business as you can usually purchase very small quantities, if needed.

--Selgus

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*Where is the best place to get the parts? I went to Radio Shack today and they only had 2 out of the 6 parts.

 

I'm lucky enough to have a well-stocked (but expensive) electronics store near me... Radio Shack has slowly become a complete joke - nothing but batteries and LEDs. When I do mail order, it's usually through www.jameco.com. They have competitive pricing, fast shipping, and are willing to deal with small quantities.

 

BTW, I have installed the Clearpic mod on one of my 1200XLs and it makes a huge difference!

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Radio Shack has slowly become a complete joke - nothing but batteries and LEDs.

 

Don't forget the new crack-cocaine of the decade: cell phones!

 

Last time I meandered into a RatShack, I told them THEY have questions and

I'VE got answers ;-) LOL!

 

And yeah, overpaying for components at RatShack that you have to order and come

back in for is a sin. Best off doing business with digikey, mouser or jameco.

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I'm placing an on-line order at Mouser Electronics and I need more info on the

 

68 pf

1000 pf

 

I was asked what style, volts, tolerance, leads

 

Anyone know what type I need?

 

Thanks,

Mark

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When I did the Clearpic2002 mod on my 1200xl, I noticed that I get an even better picture by connecting the R27-C61 junction to R181 instead of J2. But I'm using an LCD tv so maybe that's a factor.

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Anything over 10 volts is fine. Axial leads will fit the board better. Ceramic or mica is OK. Tolerance - 20% or less.

 

Bob

 

 

 

I'm placing an on-line order at Mouser Electronics and I need more info on the

 

68 pf

1000 pf

 

I was asked what style, volts, tolerance, leads

 

Anyone know what type I need?

 

Thanks,

Mark

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So, how did you connect J2-5?

 

Bob

 

 

When I did the Clearpic2002 mod on my 1200xl, I noticed that I get an even better picture by connecting the R27-C61 junction to R181 instead of J2. But I'm using an LCD tv so maybe that's a factor.

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Thanks Selgus for the two places to order on-line. Funny I started with Mouser they only had the resistors. I ended up getting the capacitors from Digi-Key. So thanks that worked out well.

 

Thanks Bob1200xl for the descriptions on what I needed.

 

Thank you everyone else for the tips and further explanations.

 

Looks like next week sometime I will be doing the mod. :twisted:

 

Thanks,

Mark

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Oops. I should have said I connected J2-5 to R181 instead of the R27-C61 junction. My bad.

 

So, how did you connect J2-5?

 

Bob

 

 

When I did the Clearpic2002 mod on my 1200xl, I noticed that I get an even better picture by connecting the R27-C61 junction to R181 instead of J2. But I'm using an LCD tv so maybe that's a factor.

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All the parts came in today. Do any of them have polarity? A Plus or Minus side?

 

 

Anything over 10 volts is fine. Axial leads will fit the board better. Ceramic or mica is OK. Tolerance - 20% or less.

 

Bob

 

 

 

I'm placing an on-line order at Mouser Electronics and I need more info on the

 

68 pf

1000 pf

 

I was asked what style, volts, tolerance, leads

 

Anyone know what type I need?

 

Thanks,

Mark

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No. None of these parts have any polarity.

 

Bob

 

 

 

All the parts came in today. Do any of them have polarity? A Plus or Minus side?

 

 

Anything over 10 volts is fine. Axial leads will fit the board better. Ceramic or mica is OK. Tolerance - 20% or less.

 

Bob

 

 

 

I'm placing an on-line order at Mouser Electronics and I need more info on the

 

68 pf

1000 pf

 

I was asked what style, volts, tolerance, leads

 

Anyone know what type I need?

 

Thanks,

Mark

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Thank you everyone that answered my many questions.

I just finished the mod today and everything went very well.

I am very impressed with the outcome.

 

:)

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Good Job, NML32! Now do this:

 

Ok. Several people have asked me about this, so i finally sat down and wrote down easy steps. Bob1200XL wrote a somewhat famous article on this YEARS ago, which has pretty much become the standard for 1200XL modders to refer to. It's kind of lengthy and also, it assumes you want to use factory ATARI ROMS for both the OS and BASIC. Since ATARI has been dead now for decades, I don't think intellectual property rights mean much to many of us where the ROMs are concerned. So why not just have both ROM sockets set up for standard 28pin EPROM configuration? Well, you can.. And its pretty easy..

 

Bob, feel free to correct me if there's something that could be done in a better/nicer way:

 

STANDARD XL/XE OS ROM

 

1. install 28 pin socket at U13 rom site.

2. replace U14 with standard XL/XE MMU (CO61618).

3. remove W6 jumper.

4. solder a wire from U21, pin 23 to the rear pad of W6.

5. make sure jumpers W9,W11, and W12 are in place, and remove all others.

6. Insert standard XL/XE OS ROM (or your custom XL/XE OS of choice on a 27128 EPROM) in U13 socket.

 

 

INTERNAL BASIC EPROM

 

1. Make sure "STANDARD XL/XE OS ROM" mod (above) has been done and works.

2. Remove 24pin socket from U12 rom site.

3. carefully cut the small trace that connects to pin 20 of U12 on the top side of

the motherboard.

4. install 28 pin socket at U12 rom site.

5. solder a wire from U14, pin 18 to U23, pin 11.

6. solder a small wire from U12, pin 20 to U12, pin 22.

7. Burn ATARI BASIC Rev.C onto a 2764 EPROM.

8. Insert EPROM in U12 socket.

 

 

Heres the result of my latest 1200XL endeavor:

OR-1200XL.JPG

XL/XE OS ROM

INTERNAL REV.C BASIC

CLEARPIC 2006 MOD

SIO POWER FIX

XL/XE 8-BIT REFRESH ANTIC CHIP

ATARIAGE PBI/CART ADAPTOR

IDEa Interface with very "custom" cable.

 

This machine belongs to Orpheuswaking.

Edited by MEtalGuy66

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Nice and easy mod description, MetalGuy66!

 

What to do if i don't have a 27C64 and want to

use a 27C128 instead, besides burning BASIC 2x into

Eprom (or add a switch for pullup/pulldown

on A13 pin of 27C128 to choose between BASIC and

on 8k Game like Star Raiders)?

 

I've done the OS mod so far.

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Good idea beetle..

 

For those who "don't get it," here's what he's talking about:

 

Let's say you'd like to have some game (one thats available on a standard 8k ATARI cart like Star Raiders, Galaxian, or Missile Command) available instantly on boot up, without using the actual game cartridge.. Heres how:

 

MULTIPLE IMAGES ON ONE EPROM IN THE BASIC ROM SOCKET

 

1. Just take your 8k BASIC ROM image, load it into a HEX editor, and then add your 8k GAME ROM image on the end of it.. Make sure your file length comes out to exactly 16384 bytes. If not, you did something wrong..

 

2. Save this file and burn it onto a 27128 EPROM.

 

3. Solder a 4.7k resistor on top of the EPROM chip, from pin 26 to pin 28.

 

4. Bend up pin 26 so it does not go into the socket. DO NOT bend up pin 28. It does still need to go into the socket.

 

5. Now get a SPST toggle-switch and mount it somewhere on the case.

 

6. Solder a wire from ground to one pin of the SPST switch. (Pin 14 of the EPROM is ground.)

 

7. Solder a wire from the other pin of the SPST switch to pin 26 of the EPROM.

 

8 Insert the EPROM into the socket at U12. Make sure all the pins except pin 26 went into the socket.

 

Now, with the switch in one position, A13 is grounded and the machine will load your game from ROM at power-up.

With the switch in the other position,A13 is pulled high by the 4.7k resistor and the machine will load BASIC at power-up.

In either position, holding down OPTION during power-up will make the machine boot with niether the game nor BASIC.

 

 

 

Now. By the same token, what if we would like to switch between two different OS ROM images?

Well, guess what...

 

MULTIPLE OS ROM IMAGES ON A SINGLE EPROM

 

1. Load both OS ROM images into a HEX editor, and graft them together, one right after the other. Make sure your file length comes out to exactly 32768 bytes. If not, you did something wrong..

 

2. Save this file and then burn it onto a 27256 EPROM.

 

3. Solder a 4.7k resistor on top of the EPROM chip, from pin 27 to pin 28.

 

4. Bend up pin 27 so it does not go into the socket. DO NOT bend up pin 28. It does still need to go into the socket.

 

5. Now get a SPST toggle-switch and mount it somewhere on the case.

 

6. Solder a wire from ground to one pin of the SPST switch. (Pin 14 of the EPROM is ground.)

 

7. Solder a wire from the other pin of the SPST switch to pin 27 of the EPROM.

 

8 Insert the EPROM into the socket at U13. Make sure all the pins except pin 27 went into the socket.

 

Now, with the switch in one position, A14 is grounded and the machine will boot with the OS you chose for the upper half of the EPROM.

With the switch in the other position, A14 is pulled high by the 4.7k resistor and the machine will boot with the OS you chose for the lower half of the EPROM.

Edited by MEtalGuy66

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Bob, feel free to correct me if there's something that could be done in a better/nicer way:

 

STANDARD XL/XE OS ROM

 

1. install 28 pin socket at U13 rom site.

2. replace U14 with standard XL/XE MMU (CO61618).

3. remove W6 jumper.

4. solder a wire from U21, pin 23 to the rear pad of W6.

5. make sure jumpers W9,W11, and W12 are in place, and remove all others.

6. Insert standard XL/XE OS ROM (or your custom XL/XE OS of choice on a 27128 EPROM) in U13 socket.

 

 

INTERNAL BASIC EPROM

 

1. Make sure "STANDARD XL/XE OS ROM" mod (above) has been done and works.

2. Remove 24pin socket from U12 rom site.

3. carefully cut the small trace that connects to pin 20 of U12 on the top side of

the motherboard.

4. install 28 pin socket at U12 rom site.

5. solder a wire from U14, pin 18 to U23, pin 11.

6. solder a small wire from U12, pin 20 to U12, pin 22.

7. Burn ATARI BASIC Rev.C onto a 2764 EPROM.

8. Insert EPROM in U12 socket.

 

QUESTION: If I add an XL/XE OS into my 1200XL with internal BASIC, will I lose the functionality of the F1-F4 keys and other 1200XL functions? I'm currently running the REV 11 1200XL OS and don't want to lose any 1200XL unique features. Will the F1-F4 keys and their functions (turn off display, lock keyboard, etc) still work with an XL/XE OS?

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I think the F1-F4 keys still work on an 800XL.

 

The OS change is OK. Bend up pin 27 and solder a wire from there to L14 (up by the CHAN switch). Or, you can cut the trace between pin 27 and pin 28 if you don't want to bend up the pin. On a 27C256, you can then choose between two OSes with the CHAN switch.

 

The BASIC mod looks funny - I'll have to check that one.

 

Let me go look at this stuff and I'll get back to you.

 

Bob

 

 

 

 

Bob, feel free to correct me if there's something that could be done in a better/nicer way:

 

STANDARD XL/XE OS ROM

 

1. install 28 pin socket at U13 rom site.

2. replace U14 with standard XL/XE MMU (CO61618).

3. remove W6 jumper.

4. solder a wire from U21, pin 23 to the rear pad of W6.

5. make sure jumpers W9,W11, and W12 are in place, and remove all others.

6. Insert standard XL/XE OS ROM (or your custom XL/XE OS of choice on a 27128 EPROM) in U13 socket.

 

 

INTERNAL BASIC EPROM

 

1. Make sure "STANDARD XL/XE OS ROM" mod (above) has been done and works.

2. Remove 24pin socket from U12 rom site.

3. carefully cut the small trace that connects to pin 20 of U12 on the top side of

the motherboard.

4. install 28 pin socket at U12 rom site.

5. solder a wire from U14, pin 18 to U23, pin 11.

6. solder a small wire from U12, pin 20 to U12, pin 22.

7. Burn ATARI BASIC Rev.C onto a 2764 EPROM.

8. Insert EPROM in U12 socket.

 

QUESTION: If I add an XL/XE OS into my 1200XL with internal BASIC, will I lose the functionality of the F1-F4 keys and other 1200XL functions? I'm currently running the REV 11 1200XL OS and don't want to lose any 1200XL unique features. Will the F1-F4 keys and their functions (turn off display, lock keyboard, etc) still work with an XL/XE OS?

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The Fx keys all work just fine.

 

OS: Step 5: you want only jumpers 11, 12, and 13. (not 9)

 

BASIC: Step 3: use a 27C128 EPROM and eliminate this step. (also, step 6)

Step 7: Duplicate the ROM data into the high addresses (copy the lower 8K into the upper 8K) and burn a 27C128.

 

U14 pin 18 should go thru a 3K (1/4 watt) resistor to +5v. (from pin 18 to pin 20 on U14)

 

This should work OK... I have a setup like this, only with the ED/ASM cart internal.

 

Bob

 

 

Bob, feel free to correct me if there's something that could be done in a better/nicer way:

 

STANDARD XL/XE OS ROM

 

1. install 28 pin socket at U13 rom site.

2. replace U14 with standard XL/XE MMU (CO61618).

3. remove W6 jumper.

4. solder a wire from U21, pin 23 to the rear pad of W6.

5. make sure jumpers W9,W11, and W12 are in place, and remove all others.

6. Insert standard XL/XE OS ROM (or your custom XL/XE OS of choice on a 27128 EPROM) in U13 socket.

 

 

INTERNAL BASIC EPROM

 

1. Make sure "STANDARD XL/XE OS ROM" mod (above) has been done and works.

2. Remove 24pin socket from U12 rom site.

3. carefully cut the small trace that connects to pin 20 of U12 on the top side of

the motherboard.

4. install 28 pin socket at U12 rom site.

5. solder a wire from U14, pin 18 to U23, pin 11.

6. solder a small wire from U12, pin 20 to U12, pin 22.

7. Burn ATARI BASIC Rev.C onto a 2764 EPROM.

8. Insert EPROM in U12 socket.

 

QUESTION: If I add an XL/XE OS into my 1200XL with internal BASIC, will I lose the functionality of the F1-F4 keys and other 1200XL functions? I'm currently running the REV 11 1200XL OS and don't want to lose any 1200XL unique features. Will the F1-F4 keys and their functions (turn off display, lock keyboard, etc) still work with an XL/XE OS?

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