No one ???

From the location it is most probably a kind of proprietary memory expansion slot.
I might have to look in the manual of my PAC 286 for confirmation.
The board looks pretty similar.

Here are some other pictures of my motherboard if it would help

Thank you

I made a research through the internet and now I Know it must be the Tandon Targa 40+

Here is my retrobrighted friend 😀

I managed to get a Trident Tvga9000 512k to connect a vga 15pin monitor because I have no monitor for the 9pin MDA graphics card but it only does show VGA bios and seems to restart. What is wrong?
https://youtu.be/klV2OidLHVY

eisapc wrote on 2020-08-04, 07:53:

From the location it is most probably a kind of proprietary memory expansion slot.
I might have to look in the manual of my PAC 286 for confirmation.
The board looks pretty similar.

Do I have to switch something too to get a vga card running?
In a previous post i posted a video with my actual problem.

GuillermoXT wrote on 2020-08-14, 19:36:

Do I have to switch something too to get a vga card running?
In a previous post i posted a video with my actual problem.

Possibly. You do have a nice switch set there.

Knowing what to switch is the issue. I don't know if you can damage something by setting the wrong switches.

If you don't care, I would move one switch at a time to see if video appears, and of course set it back and move to the next one if not.

hwh wrote on 2020-08-14, 21:11:

Possibly. You do have a nice switch set there. […]
Show full quote

GuillermoXT wrote on 2020-08-14, 19:36:

Do I have to switch something too to get a vga card running?
In a previous post i posted a video with my actual problem.

Possibly. You do have a nice switch set there.

Knowing what to switch is the issue. I don't know if you can damage something by setting the wrong switches.

If you don't care, I would move one switch at a time to see if video appears, and of course set it back and move to the next one if not.

May you have an idea what it means when the mfm hdd led is blinking 3 times?

I bet this is the horrid Miniscribe hard drive?

Cheers,

pentiumspeed wrote on 2020-08-15, 14:09:

I bet this is the horrid Miniscribe hard drive?

Cheers,

No the Tandon Tm 262 40mb hdd

Cheers

SOS morse signal means hard drive cannot initialize usually the seeking to zero track and did not get zero track signal via switch or optical interrupter at right time. (error found or certain tests is not expected) into readiness before hard drive MFM controller can query the hard drive during the POST startup process.

Many MFM hard drives has own internal start up tests/ recalibrate seeking to make sure it's good before releasing itself to the hard drive controller.

Cheers,

pentiumspeed wrote on 2020-08-30, 23:40:

SOS morse signal means hard drive cannot initialize usually the seeking to zero track and did not get zero track signal via switch or optical interrupter at right time. (error found or certain tests is not expected) into readiness before hard drive MFM controller can query the hard drive during the POST startup process.

Many MFM hard drives has own internal start up tests/ recalibrate seeking to make sure it's good before releasing itself to the hard drive controller.

Cheers,

Thanks

Sometimes I can get the mfm running but it still doesn't Post....any ideas ?

Could try putting a few drops of oil in the stepper motor (the black square thingy on the side of the drive), it could be that it's gummed up and can't spin freely.

Hey my retrofriends ✌

Meanwhile i got my Tandon running. My issue for the bootloop the 286 had was the VGA was set as "bios Autodetect". I disabled the detection and it booted finally.
I swapped the RLL HDD out and inserted an XTIDE-CF unit with a 4GB Card (2x2Gb partition in DOS 5.0)....little bit Overkill i know ^^
Then I installed a 3mb ISA Ram module after searching without success for the proprietary Ram extension, swapped in a 10MHz Coprozessor found in a online flee market(German Ebay-Kleinanzeigen), a SB16 running Unisound (thx to Jaze Fox), an IO controller for the 4xspeed CD Drive (want to try if i can get the IDE header from the SB16 running to save a slot for a network Card),
a second 3.5" floppy drive and last but not least exchanged the LOUD PSU-Fan with a brand new one manufactured by Noctua. I newer saw such a silent 286 PC 🙂
There i one more thing I would like to change:
I know there has been a plus model with 10,7 mhz instead of 8MHz in mine....how did Tandon speeded it up without a 20MHz oscillator?
Here are some pictures