spinnaker15136

So can I do at least part of the alignment procedure without the special disk and cartridge? Will the 1050 alignment kit work on the 810? From what I remember Best sells both. Would be nice to be able to buy just one in case I get a 1050.

Trying to follow the calibration procedure. First I don't know how they expect you to get a probe clipped onto those components. C155 looks like a resistor to me. C154 a diode? Maybe a glass cap? Never saw one of those. Am I reading the diagram correctly? Probe goes on the "top " of C154 and "bottom" of C155?

Yes and yes. Multiple disks do not work. And as I recall. This was the issue when I put it away 30+ years ago.

Making big progress. Reseatted all chips again. Also Q104 appeared to be smashed down with leads touching. Straitened the leads. Disk drive is now responding to power on of computer but I get a boot error. I am on a work break from my real work right now but wanted to give this update. Later I will look at the manual for timing procedure. At least SIO appears to be working.

Well I really should be headed off to bed but had to giv that flow chart a quick look first. If I followed things right I get to Does motor and busy light go off after 7 seconds which it does. So I go to 8C-22 which is the diagnostic cartridge which I do not have. I will try to check out the rest tomorrow but need to get some sleep.

Oops sorry. Not thinking. Just got back from the emergency room for my 93 yo mom for the second time this week after giving her the Heimlich for the second time this week. Finally got them to admit her tonight.

Correct on startup. Switches are set correctly. No difference on startup sound or operation. Few seconds of buzzing then Memo Pad. Might as well continue on this thread http://atariage.com/forums/topic/290460-reading-writing-the-atari-400-800-serial-port/ since it has morphed into an 810 repair thread.

Old electrolytic caps tend to dry out. A lot of people say they should be repaired. I dumped my old Tek for a digital scope after repairing it (think it was a deflection issue) and saw how packed that PSU was. I dreaded having to tear into that so on eBay it went. I replaced more than my share of filter cap on old TVs. It was really funny with some customers that knew just enough about TVs to be dangerous. They were bound to ask you if it was THE condensor or THE tube.

We must not have the same 810 service manual. The one I have only has 10 chapters. Last page is 10-5.

Just as a reminder computer goes immediately tp Memo Pad when DOS is tyoed or computer is turned on with no cartridge.

What should I look for on the switches? I have confirmed that they are set correctly. I do see the PSU right after that but don't see where they can be found on the board. I am still can't locate -5V Not finding references to "and the chip for id select." I do see the reference to the PIA that reads the switches. Is there a physical layout of the 810 boards somewhere? Just finding a schematic.

I did a continuity test. Pretty sure SIO cable is good. Will check manual thanks.

Thanks for the CSAVE tip. SIO appears to be working. At least output. I entered a few lines in BASIC. Typed CSAVE and heard a tone on the TV speaker. Square wave appeared on scope.

Already mentioned disk drive goes though power up procedure. Head moves disk spins. I have +5V +12V in the 810. Not sure where to find the other voltages. Looked at the 810 service manual but did not see where they were located.

Where would I get such a thing? Checked on ebay did not see it. Is it just the cable? What is considered "cheap"?

Yes cleaned the heads. I tried a couple of different disks. But the head does not move at all. Clean / bad head or bad disk, shouldn't the 810 at least try to read? And can someone refresh my memory? With BASIC cart in, I type DOS correct? Will that cause DOS to be loaded in memory? Right now it just goes to memo pad. And with no cart, nothing happens on power up of the computer. Just to make sure I am doing it right. Power up 810 (it goes trough its power up routine). Power up computer with no cart. Bootable disk should be loaded correct?

Never used CSAVE. Can I place it in a line of the code and loop to it? Working right now, on a brak but I could try it later.

Already tried those things thanks. Including reseatting all chips in the 810, all connectors and the side board. 810 goes though the power up routine but does not load a disk. Will CSAVE still try the SIO even if there is no device responding?

Yeah found that just before I turned in last night. Thanks.

Than again maybe not so promising. But it looks like $E459 is the wrong track. Looks like that is for talking to one to the devices. I think I need to go deeper since I really don't have a device. Unless it is going to put data out on the port anyway? OK time for sleep now. Really.

This looks promising https://www.atarimax.com/jindroush.atari.org/asio.html But time to get some sleep now. Real work tomorrow..

$300 is the device handlers. $E459 looks more promising but I can't make heads or tails of what that document is trying to say. But I think I need to go deeper. I think I nee to set the clock with AUDF4 $D206 but still havn't figured out how to set the frequency. Then set bit 5 of SKCTL $D20f Found this in my OS guide. Again not entirely sure I understand what they are saying about it in the memory map in the link you provided. Finally write to SEROUT $D20D I addition to the frequency of the clock, what I can't figure out is how to know if the transmit buffer is busy or not. I can't remember if I can poll it or have to use an interrupt vector. Of course I would like someone to confirm all of this theroy. I must have been a lot smarter close to 40 years ago.

Can anyone point me to a simple code example for talking to the SIO port? I did this about 30 years ago and darn if I can remember how. I know I had to set the audio frequency register for the clock or baud rate. but still trying to digest the OS manual on how I did that. for the desired frequency. also I know that I set SKCTL for async but in this instanse I want to use sync. Can anyone help? Basically I am trying to determine if my SIO is working on the 800. This thread looked promising but I am not seeing the Atari end of the code. http://atariage.com/forums/topic/209010-sio2pi-raspberry-pi-as-a-floppy/

I couple of repair type questions I have had go unanswered. Hey no complaining. I just understand folks do their best to help This just might not be the best forum for repair. Hang out on an Electronics forum with lots of helpful people. But when I had a problem with my tech scope they couldn't help me. Said I should Join the Tech mailing list. My scope was fixed days after I joined. So is there a repair forum out there I should be joining? If so PM me if need be. Thanks

I used Borland Turbo Pascal long before C.