800 & 130XE Novice needs Guidance!

[ijeremy]

Ok all... please be gentle as I'm way out over my skis here! Lol. I've been an avid late 80's/Early 90's 286-486 PC collector for some time and have been interested in getting into Atari's 8-bit machines for a while but haven't taken the plunge. Well, I stumbled across this lot in a box at Savers today and couldn't leave it there as I never see stuff like this in the wild. Problem is, I have no idea what I'm getting into! From what I can tell both the 800 and 130XE have been modified. The 130XE has an Omnimon board by David Young but it won't boot... I tried both the 'Monitor' out and RF and both screens look the same. The 800 boots but keys "esc through 6" on the top row are unresponsive, could be something simple but I haven't cracked it open to see what's going on. I started to open it and found what looks like additional RAM/ROM and figured it was time to post pictures and get some more information from the experts. Excited to learn but a little overwhelmed with them already being modded. I'd love to sort the 130XE and fire up some games. And sorry about the PCjr looming in the background!

 

[JR>]

Nice haul! The fact that you have actual characters on the screen is a very good sign. Step 1.....carefully re-seat all boards and socketed chips.

[Keatah]

The 300-baud SmartModem is a thing of beauty. Highly sought after in the right circles.

[JR>]

Both computers have Omnimon boards, which allow you to switch between the stock OS, the Omnimon OS and possibly the Omniview 80 column OS. Some of the switches will be for those boards. Looks like the 800 has a 16K and a 32K RAM board. Big button on the 800 is probably a cold reset.

 

The 1050 appears to have a Happy Enhancement which adds many nice features and the ability to copy many protected diskettes.

[ijeremy]

Thanks JR! Good info to study/learn about.

[chad5200]

I’m thinking that you don’t want to switch that OS switch while the computer is on, right?

[JR>]

I’m thinking that you don’t want to switch that OS switch while the computer is on, right?

Most likely the computer would crash, but no physical harm would be done. The 800 version is a little different as only a small, normally unused 4k chunk of memory is being switched around.

Edited May 20, 2019 by JR>

[+slx]

Those switches on the 800 hurt, guy probably didn't have enough cable around and/or time to move them to a less conspicuous position...

 

You were lucky to find such a "non-standard" config in the wild.

 

Did you try booting them with all switch positions? The UP position on the 130XE should you land you in BASIC. If those brown wires are not connected to the Omnimon board but belong to some other hack you could also take out the Omnimon board and just use the CO61598 OS chip for testing.

 

The 800 should come up with a "memo pad", basically a blue screen where you can type, when booted with its stock OS. IIRC the Omni OS does not have a prompt at all and might have a different screen color.

 

When you switch it on the Atari should make a kind of rasping sound while it looks for boot devices and then end up as described above. Most game cartridges bypass this and boot right into the game.

[+slx]

Most likely the computer would crash, but no physical harm would be done. The 800 version is a little different as only a small, normally unused 4k chunk of memory is being switched around.

Aren't there versions that replace the whole OS with an Omnimon OS (replacing the memo pad, etc.)?

[JR>]

Aren't there versions that replace the whole OS with an Omnimon OS (replacing the memo pad, etc.)?

The Newell Ramrod board allows for swapping out all of the OS blocks of the 800.

[ijeremy]

 

The 800 should come up with a "memo pad", basically a blue screen where you can type, when booted with its stock OS. IIRC the Omni OS does not have a prompt at all and might have a different screen color.

 

When you switch it on the Atari should make a kind of rasping sound while it looks for boot devices and then end up as described above. Most game cartridges bypass this and boot right into the game.

 

Thanks slx, the 800 does indeed boot to Memo Pad or Basic depending on the position of the switch on the far right. It must boot to Omni OS as well depending on the switches in the middle as one configuration seems to boot without any text or cursor. I haven't had much time yet to mess with either system much but it seems the only issue with the 800 is the esc through numerical 6 keys on the top row are unresponsive, thus rendering Basic pretty useless. I'll try to tear into them some more when I get home from the office and see what else I can figure out. One this is obvious at this point, neeeeeeed some software!

[JoSch]

These keys are all on the same row in the keyboard matrix: http://members.casema.nl/hhaydn/howel/logic/burched/b5_800xl_kbd.htm(All Ataris have the same matrix).

So either the line itself is dead or the corresponding 4051 pin is dead. Perhaps reseating will help.

Helpful for any repairs is the service manual (http://www.atarimania.com/documents/Atari_400_800_Field_Service_Manual_June_82.pdf).

[ijeremy]

These keys are all on the same row in the keyboard matrix: http://members.casema.nl/hhaydn/howel/logic/burched/b5_800xl_kbd.htm(All Ataris have the same matrix).

So either the line itself is dead or the corresponding 4051 pin is dead. Perhaps reseating will help.

Helpful for any repairs is the service manual (http://www.atarimania.com/documents/Atari_400_800_Field_Service_Manual_June_82.pdf)

 

That's great info & thanks for the links. I love how much of these boards are socketed. I have a collection of old arcade games & pinball machines and just assume I'll need to vacuum solder every time I look at electronics from this era! Fingers crossed for a simple fix here.

[+slx]

When you disassemble the keyboard, check whether it's a Mitsumi. They have a mylar which fails. You should be able to google repair instructions or find them here on the forum, and user duddie is preparing a new mylar.

 

I only tried an Omnimon OS once but I think it does not have any prompt.

 

Here's the manual for the Omnimon OS on the 800.

[_The Doctor__]

to start out keep all switches in the normal XE or 800 modes.. (no 80, no OMNI)

 

always push the chips into the socket before pulling them out, btw, that will avoid bending or breaking weak swipes.

 

If you have the drive etc. connected during your boot up... hold the option key down to disable basic... garbage on the screen often happens when basic is active when running machine language programs... keep the basic cartridge out of the 800 to avoid that same issue.

 

On the XE, if nothing is connected or all attached devices are turned off, holding down OPTION while powering the XE up should get you the SELF TEST screens

Edited May 20, 2019 by _The Doctor__