DavidMil

How about we trade: your box of external modems for two boxes of my 56K (and slower) internal modem cards. Lately I've been using them to fill in low spots in my yard! David

I think my old 300 baud Hayes Smartmodem is working (at least I can get a dial tone and dial out), but I was wondering if anyone has a 'best communications' software suggestion to use with this modem. I tested with Bob Term 1.2 and XE Term. I'd also like to get some more info on initialization strings. I do have the manual with all the commands, but there is nothing in the docs that says more than 'use this command in the initialization string to do...'. Any help would be appreciated! Thanks, DavidMil

On second thought, after another round of Brasso and 0000 grade steel wool, it looks really good. So I'm going to spray a thin layer of polyurethane on it and call it good. David

I look for via holes close to where the trace was cut and put one end of the wire into it and the other end into the socket for the IC. Try to keep the wires about the same length as the cut trace. For timing purposes. However, as slow as 8 bit Atari's were, it's not that critical. And Osgeld is right on with #30 wire wrap wire. That's what I use too. DavidMil

Are you asking for a number 4 keycap for the 600XL? If so MyAtari (www.myatari.com) has them. DavidMil

Steel wool by itself didn't do much so I added some Brasso into the mix. The end result looks very nice. I will still nickel plate it though. Here's a couple of pictures...

Seems like I remember someone making a weather station using one or maybe two RS232 ports to communicate with the 850 over a couple of 50 foot speaker/phone wires. One 232 port was for the temperature and I'm not sure if the other was for wind speed or rain. Sorry, that about 34 or 35 years ago, and the RAM space in my head could use some serious replacements! David

I actually have a good one, and I saw that someone (I think in Europe) had some for sale on eBay. A bit pricey though... David

So you actually have the groves on the back of the rubber print head? That is much better than glue, and Stefan and I had agreed that shore 60 was about right (we were close). Again, my hat is off to you, and seeing my old 1027's print again is ample compensation for any hurt! Congratulations! David PS. I still what four when you are ready to ship! DM

I forgot to mention that R56 is 4.7K (which you are also reading across) and when you add R57 into the reading you would get about 5K ohms. Close enough to the 4.893 that you were reading (if you had an auto ranging ohm meter). You may want to check across R56 alone to see what you are reading. If it's not close to 4.7K, I would raise one leg of R57 and check it again. We are getting side-tracked from your short problem though... David

I bought one of Best's replacement Mylar's and my 1200XL keyboard works perfectly now. They are a little pricey as they have gold contacts but they are guaranteed for life. Be sure you follow the online instructions for replacement! DavidMil

Very Impressive! It also hurts a bit... I've been working on creating a casting of the rubber print head. I had two 'good' print heads to work with. During the first attempt, the mold casting material dissolved a good portion of the first rubber print head. So I put my backup in the freezer as someone suggested. When I got it out to try another casting, I found that during the freezing the rubber print head cracked and split in many places. Well, at least I got a nice degassing chamber out of this. Irgendwer, how did you attach the rubber printhead to the print wheel and what hardness (shore value) did you use? Also will you be selling these anytime soon? I want four! Nicely done! David Milsop

Jpc18, Please forgive me but I have to ask: You are on ohms and not kilo ohms scale right? The way you have the probes set there, you are reading across the E-B (Emitter, Base) junction of Q6 and through R57. If you are reading 4.893 ohms, you have a serious problem there. David

SignGuy19 is correct, without the cartridge installed and Q9 powered on, Q8 won't turn on and give a path to ground for Q6 and Q7. Jpc18 did you ever lift one leg of the four caps and two Ferrite Beads (C36, C37, C119, C122, L7, and L10)? This will tell you which of the three 5Volt power rails (5A, 5B, VCC1) has the short. To avoid any miss-readings, I would raise the legs of L7 and L10 that are connected to the large trace that connects the two inductors on the top of the board. David

I'm so sorry that I forgot to tell you that all of these things are easily correctable or can be overcome. Sorry, David

High untreated blood sugar can cause that same problem. Low thyroid can cause that problem. High uric acid in the blood can cause that problem. Like someone said, a mild stroke can do it too. Also low O2 can cause problems like this. If the symptoms start suddenly it's not as likely to be Dementia/Alzheimer's. You hang in there and I'm sure many of use will include you in our prayers! David

Cool! Thanks, David

CI2 goes to pin 36 of the cartridge slot. You can ohm it out to make sure. Put one lead on the side of R57 closest to the heat sink and the other on pin 36 of the cartridge socket. I'm going to tell you that the 5200 schematic is not the easiest to follow. From what I'm looking at (via the schematics), power is on VR1 even when the power button is off. SignGuy81, would you agree with that? David

Look on page 2-27 of the schematics (Fig. 2-12) This is the power supply/distribution section of the schematics. Look at the base of Q6 and Q7. CI2 is connected to Q6 via R57, and CI1 is connected to the base of Q7 via R58. R57 and R58 are large resistors on the right edge of the board. Do you not have pages 2-27 and 2-29? I can put them out here for you. 2-29 is a picture of the top of the MB with part numbers listed for each component. VCC1 is connected to the output of VR1. David

The manual that sm3 sent you should have a page on modifications (updates) that can be made by the purchaser (you). Look closely at my pics, you'll see the info about the switch. David

That is a strange problem. My first thought is that it is one of the big chips, but it could be a funky cap or a bad transistor too. With all the chips soldered down, you going to have a fit trying to get to the bottom of this. I think that what I would do is raise one leg of one of the three inductors L1, or L2, or L3 and look for a change in the display. If raising one does nothing, leave it up and try raising another. If that does nothing put the first leg down and raise the last inductor. This will at least give you an idea of which set of chips or components connected to each 5 volt rail are causing the problem. The 6502 chip (CO14806) is not soldered down is it? Just for an hopeful easy fix you may try swapping that one out first. My fist guess would be the GTIA or Antic chip if replacing the CPU does nothing. You might want to wait a bit and see if someone has had this symptom before and has a better idea of what the problem could be. One word of caution: When you raise the leg of the inductor that supplies power to the video circuitry of course the screen will go black. The above method is just a crude first check to isolate a quick fix. David

I wonder if this person thought about making the keyboard detachable? I'd have to go up into the attic and cannibalize a 800 ribbon cable off of an old 800 keyboard ( I have several that have missing/nonworking keys). You'd have to remove that connector and solder the replacement ribbon cable onto the keyboard. Either that or look online for 18 wire ribbon cable. If you are interested let me know. David

Before you do all that I would suggest that you do a fast voltage check and see if you are still loosing power (not getting 12V on the MB) with VR1 removed. If the voltage is good at this point you will know for sure that the problem is beyond VR1. If it's still low, kill the power and do and ohms test between either L7 or L10 and ground. If you're not getting a very low reading (a few ohms or less) at one of these points, I would think that we need to look elsewhere. I just had a thought... Look in the cartridge socket and make sure there are not any bent connectors or small loose metal objects (like maybe a solder ball). VCC1, CI1, and CI2 all got to the cartridge socket, and create a short potential. CI1 and CI2 are right next to the ground connector in the cartridge socket. David

And VR1 is still Removed Right? David

Is that connector soldered into the top of the circuit board under the keyboard? That's what it looks like in the picture. I've never seen one like that. All that I've seen have the ribbon cable soldered into the bottom of the circuit board and a female connector on the end of the ribbon cable that plugs into the computer. DavidMil