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TeleVideo 286 Machine - Need help!

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First post, by foxyloon

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Hello! Although I'm rather new to the forum, I've been dabbling with vintage PCs for many years and learned quite a lot in that time. Yet the oldest PC I've ever worked on, up until recently, had been a 386, so my knowledge is rather limited for anything older. In other words, I'm used to working with machines that have ROM configurable BIOSes and IDE hard disks, not a machine that uses an MFM hard drive and requires a setup disk to configure.

For the longest time, I wanted an old IBM AT machine to play around with, but settled for a "clone" machine instead. It's a TeleVideo "TeleCAT 286" that I bought from a local game shop early this year. It came with the original TeleVideo branded EGA monitor, driven by an ATI EGA All-in-wonder card, and an XT-IDE card that was installed by the store owner so he could "prove it can boot DOS". Unfortunately, it didn't include the important stuff, like the user manual or any TeleVideo branded setup disks. The only references I could find to the machine online was the store owner's eBay listing of the exact machine I bought, a board pinout chart from stason.org https://stason.org/TULARC/pc/motherboards/T/T … ELECAT-286.html, and a couple ad flyers from 1987 that indicate the machine did actually exist. Yet I can't find anything useful, like an image for a setup disk, or documented jumper configuration options. The store owner told me up front that he couldn't get any of the drives to work, and decided to sell it instead of delving deeper into this project.

The first thing I tried to do was replace the dead lithium 7.2V CMOS battery, which proved to be a rather difficult battery to find. I ended up putting six AA batteries in series to get me close enough to a working voltage.

I've yet to get any of the floppy drives, let alone the old ST-225 MFM drive, to be recognized at all within DOS, but it boots like a champ from the 2GB CF card on the XT-IDE controller that came with the machine. My main goal is to recover any remaining data from the ST-225, and maybe put it back into service, but I don't have another MFM controller laying around to confirm it works. I have reason to suspect that the ROM from the XT-IDE card is causing conflicts with the current BIOS, since GSETUP hangs every time I try to run it within DOS 6.22 from the CF card. (The only thing the machine can currently boot from.) So I tried to make a bootable 360K formatted floppy. That plan went up in literal smoke when the original Teac 360K drive fried on me in my Pentium machine, and was the only 360K drive I owned. (I've since tried purchasing another 360K drive, but that's been it's own set of problems. Let's just say the used drive I bought on eBay was DOA.) When I tried hooking up a "more modern" 3.5" floppy drive to the machine, it obviously didn't work since I can't configure the BIOS to recognize anything other than a 5.25" 360K drive for drive A. For the record, it has a second Toshiba 1.2MB 5.25 floppy drive, that I was able to confirm still works in my Pentium machine. (If only I could configure the BIOS to set drive A to a 1.2MB drive...)

I've now resorted to finding an alternative BIOS that I can write to a couple 32K EPROMs, and that's where I truly need assistance. I have a UV eraser and TL866 plus programmer handy, but I need help finding a ROM that's compatible with this machine. It's either that, or getting my hands on a working 360K floppy drive and rolling the dice that it'll actually read and boot with this machine. (I also took backups of the current ROMs, so I can put the machine back to "stock" configuration if need be.)

Any insight or input would be greatly appreciated! I want to see this old lady back up and running again, so I can finally move on to another project. (I'll gladly take a few pics of the motherboard, so we can figure out what kind of chipset it uses.)

Reply 1 of 20, by Predator99

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I think without pictures of your board/chipset/BIOS screen/disc-controller it will be difficult to help you.

I general the XT-IDE can coexist with a MFM-controller. A 1.2 or 1.44 MB floppy should be supported in all 286. GESETUP may not be compatible with your PC. Is there no build in BIOS setup?

Reply 2 of 20, by evasive

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30 seconds of Google-Fu:
http://vtda.org/docs//computing/Televideo/129 … anual_Jul86.pdf

added here BTW:
http://www.win3x.org/uh19/motherboard/show/4890

If we find info (and if hopefully you post pictures and a bios dump) we will expand that page.

Reply 4 of 20, by foxyloon

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evasive wrote on 2021-04-07, 19:41:
30 seconds of Google-Fu: http://vtda.org/docs//computing/Televideo/129 … anual_Jul86.pdf […]
Show full quote

30 seconds of Google-Fu:
http://vtda.org/docs//computing/Televideo/129 … anual_Jul86.pdf

added here BTW:
http://www.win3x.org/uh19/motherboard/show/4890

If we find info (and if hopefully you post pictures and a bios dump) we will expand that page.

Thank you, so much! I searched for hours and never stumbled across a single pdf copy of that manual. That's already a good start!

Here's the dump from both chips. Looks to be a pair of 16k Intel D27128As, classic "Even/Odd" pair. The labels are badly degraded, but legible with the right lighting. The filenames of each bin file are what I could read from the labels.

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Last edited by foxyloon on 2021-04-07, 20:14. Edited 1 time in total.

Reply 5 of 20, by foxyloon

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evasive wrote on 2021-04-07, 19:57:

Had to register, but I have the disk images downloaded, too! Just need a working drive at this point, unless I can copy the contents over to the CF card.

Again, thanks for the help!

Reply 6 of 20, by foxyloon

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Predator99 wrote on 2021-04-07, 18:41:

I think without pictures of your board/chipset/BIOS screen/disc-controller it will be difficult to help you.

I general the XT-IDE can coexist with a MFM-controller. A 1.2 or 1.44 MB floppy should be supported in all 286. GESETUP may not be compatible with your PC. Is there no build in BIOS setup?

As for pictures, my phone takes them at an absurd resolution. I'd have to manually compress them somehow, so would it be okay to just zip them and post the compressed files?

Reply 7 of 20, by foxyloon

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Well, I thought I'd leave a quick update/prognosis. The pictures of the boards have been putting up a fight when I try to upload them here. I've tried several means of compressing the pictures of the boards, but this site just doesn't seem happy with them. At least the setup disk worked, and the machine even booted off of the second remaining floppy drive with said setup disk! The XT-IDE ROM has proven useful here, since I can press the A key to force it to boot from the floppy drive.

The "setup" program updated the configuration settings as desired, (Date/Time, RAM config, drive config, etc.) but said utility doesn't detect the hard drive at all. At POST, the machine displays an "8E Hard Disk Failure". Either the controller card has issues, or the drive itself has failed. At soon as the drive spins up, the head makes a loud clicking sound for about thirty seconds before it does a proper seek and stops, presumably giving up, so I'm thinking this particular drive had a head crash.

I'm about to perform an autopsy on the drive to see what the problem is, but I fear it may be a lost cause.

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Reply 8 of 20, by evasive

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foxyloon wrote on 2021-04-07, 20:14:

As for pictures, my phone takes them at an absurd resolution. I'd have to manually compress them somehow, so would it be okay to just zip them and post the compressed files?

Yep, we will process them for publication anyway.

Reply 10 of 20, by Vynix

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From what I know the ST-225 makes constant clicking sounds when it initially starts up before making a normal seek.

There's a chance that the MFM card is faulty or isn't making proper contact in the ISA slot (try unplugging it and putting it back into the ISA slot).

Proud owner of a Shuttle HOT-555A 430VX motherboard and two wonderful retro laptops, namely a Compaq Armada 1700 [nonfunctional] and a HP Omnibook XE3-GC [fully working :p]

Reply 12 of 20, by foxyloon

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Vynix wrote on 2021-04-08, 10:32:

From what I know the ST-225 makes constant clicking sounds when it initially starts up before making a normal seek.

There's a chance that the MFM card is faulty or isn't making proper contact in the ISA slot (try unplugging it and putting it back into the ISA slot).

I popped the drive open and found that everything looked normal, except that the platters are just beginning to form rust. I quickly closed it back up, and confirmed that the clicking is normal behavior. It even did a seek test, so I know the stepper motor isn't seized or anything crazy like that.

As for the MFM controller, I'm fairly certain it's at fault at this point. With this particular machine, TeleVideo decided to integrate the floppy controller and MFM controller into a single 16-bit in-house designed card. I've swapped it between several of the ISA slots, and even scrubbed the card connector with cue-tips and rubbing alcohol. Even tried it in my Pentium machine, which resulted in the exact same results. The floppy controller section worked fine, but no dice with regards to getting the system to recognize the hard drive.

Predator99 wrote on 2021-04-08, 11:39:

Try Speedstor for mfm diagnosis. Put the Program on your Boot Floppy and run without the IDE Controller installed. Speedstor will also test the mfm Controller.

I'll definitely give Speedstor a try, but if the rest of the system can't even talk to the drive, I'm doubtful if it'll recognize the drive at all.

Reply 13 of 20, by foxyloon

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evasive wrote on 2021-04-08, 08:33:

Yep, we will process them for publication anyway.

https://drive.google.com/drive/folders/1OjIeK … 5IH?usp=sharing

Here are the raw images. (8MB each) Let me know if you need more pictures of specific ICs. (Looks like the flash may have obscured a few of them.)

Reply 14 of 20, by Predator99

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You opened the drive just for checking....??! You know you need a Clean room for that? No comment on that...

Very unlikely only the MFM Part of the Controller is not working. MFM is much more complicated to set up compared to IDE.

Reply 15 of 20, by Schule04

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Are you sure that the HDD is the original one? If it came from another machine with a different controller card, it often has to be low level formatted to be usable.

Reply 16 of 20, by foxyloon

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Predator99 wrote on 2021-04-09, 06:45:

You opened the drive just for checking....??! You know you need a Clean room for that? No comment on that...

Yes, I know. A clean room is supposed to be used, especially for newer voice coil drives where the tolerances are insanely small. I assumed an older stepper motor style drive would be more tolerant to dust, especially since I replaced the cover within 30 seconds after seeing it was fine. I know doing that wasn't ideal, but I needed to know the condition of the internals. Hopefully I didn't kill a perfectly good drive...

Predator99 wrote on 2021-04-09, 06:45:

Very unlikely only the MFM Part of the Controller is not working. MFM is much more complicated to set up compared to IDE.

I'm inclined to agree, after looking into the process of configuring MFM drives on IBM machines. It's looking more and more like I'll have to do a low level format, which is going to be my very last resort.

Schule04 wrote on 2021-04-09, 07:04:

Are you sure that the HDD is the original one? If it came from another machine with a different controller card, it often has to be low level formatted to be usable.

I considered that as a possibility, especially because I bought it as-is, with no known prior history. The only things I can confirm are that the ST-225 is listed in the manual as one of the five drive makes/models these machines came with new, and that it's proven to be quite involved to remove the hard disk from the case. Involved enough to scare away most who are less technically experienced.

I've tried using the utilities on the Televideo diag disk, but none of them detect a hard drive to be present, despite checking every ribbon cable and jumper I could find. I've yet to try Speedstor, but that's my next step.

Reply 17 of 20, by evasive

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foxyloon wrote on 2021-04-08, 22:48:
evasive wrote on 2021-04-08, 08:33:

Yep, we will process them for publication anyway.

https://drive.google.com/drive/folders/1OjIeK … 5IH?usp=sharing

Here are the raw images. (8MB each) Let me know if you need more pictures of specific ICs. (Looks like the flash may have obscured a few of them.)

If at all possible we would like to have one picture of the entire motherboard, front and back. We can work with perpective corrections and lens corrections but the important bit is we have the whole board. Don't worry about the file size, we can manage that.

Reply 18 of 20, by foxyloon

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Sorry for taking so long to get back to you guys. This past month has been a rollercoaster of events and emotions, with the death of my father being one of said events. For all that talking I did earlier, I just feel outright foolish for making such a big deal out of what's supposed to be just a hobby project. At the time, I was worried I was going to abandon this machine like a ton of my other side projects, but life goes on and things come up. Despite my efforts, life found a way to force me to stop working on this machine.

So I've attempted working on the TeleCAT again recently. So far, it consistently boots from the A drive, whether using a 5.25" or 3.5" 1.44MB floppy drive. (Like a lot of people were saying.) The setup utility explicitly states "high density disk" as an option for configuring the drive. Also, it seems that setting the RAM parameters in setup also helps tremendously with system stability. Go figure the defaults were incorrect...

The problem now is that I've been having issues making a usable boot disk with SpeedStor on it. I'd normally just use a Win9x machine, like the Pentium machine I mentioned earlier, to make a proper boot disk with. Currently, all my vintage PC stuff is either in pieces, missing vital parts, or outright buried among a ton of stuff I have in storage. The only machine I still readily have access to is my modern gaming PC, and a Sony 2X USB floppy drive.

evasive wrote on 2021-04-08, 08:33:

If at all possible we would like to have one picture of the entire motherboard, front and back. We can work with perpective corrections and lens corrections but the important bit is we have the whole board. Don't worry about the file size, we can manage that.

A full shot of the top and bottom of the motherboard, in a single take, as requested. Just uploaded two more images to the Google Drive link provided earlier. Ended up having to grab my old Kodak EasyShare Z5010, as the lens view angle on my phone isn't anywhere near wide enough to capture the whole motherboard in a single take. (It was either use another camera, or take a photo of the motherboard on the floor.) Hopefully the new pictures are satisfactory.

Reply 19 of 20, by evasive

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First of all, my sincere condoleances. Please take your time to process the loss of your parent. From my personal experience, it does need time, give it time.

The new pictures have been added to the page. They are well worth the wait.

Thank you and stay strong.