Found the keyboard shortcut that changes between 10mhz and 4,77mhz, its CTRL+ALT+Enter .

Here are some pics of the rework I did on this, it's working perfect (so good that I'm gonna make it my main XT setup)

- Acid corrupted both serial and lpt ports , you can see their shielding it was in terrible condition. All pins were green...

replaced both ports , cleaned and painted that metal piece that acts as a cover for them:

- Acid also damaged the area around the battery - the ISA slot next to it had green pins too. All fixed and neutralized now.

I am currently debating whether I replace the 8088 cpu with a V20 and if I want to install another battery for the RTC... 🤣

Nice work saving the board, bit (ok way) to early form my needs but looking forward to it being finished, drives and all

Wow, looking fantastic. Always makes me feel warm and fuzzy seeing people save and restore old PC's

Thanks!!!
Still needs more tinkering but I did take it home for the weekend to test it out. Because I did not want more converters hanging outside (mainly the CGA->RGB one) and it was easier to test next to my main pc, I temporarily installed a VGA card (other cards are a SB1.5 CT1320C and the XTIDE rev2 interface with a CF):

In the last picture you can see Matze79's serial->ps2 mouse adapter and the AT2XTKB adapter , both VERY useful since you can use modern mice/keyboards with old machines.

Generally I'll say that the machine is very enjoyable - keeping in mind it's limitations. Using a VGA made it possible to test some VGA/EGA stuff as well.
Commander Keen 4/5/6/dreams run , they are playable but somewhat on the slow side.
Dangerous Dave in Haunted Mansion is fine, Risky Rescue has long load times but it's playable in the end - ofcourse it has less fluid scrolling.
Tried Space Quest 3 and King's Quest 3 , they do have some load times but they are fine too.
Dynablaster ran great - quite a surprise for me, Jill of the Jungle was on the slow side of things, I can't say it was enjoyable.
Eye if the Beholder 1 was OK - bit on the slow side as well but it doesn't matter that much in it.
Zeliard was fine as expected.

The machine seems to have proper 4.77mhz slowdown , both Sysinfo and 8088MPH agree to that:

here is sysinfo @10mhz:

8080MPH runs fine and it even completes the last part with the credits and the sampled music. I ran it with the VGA so the screen was all wrong but it didn't freeze or anything.

I have ordered a V20 @10mhz , it should give a little more juice but more importantly some more stuff might run with a V20. Will give it a test when it arrives.

There is still some work left to do, I need to replace an ISA slot that I just noticed has discoloration in some pins (due to the battery acid) and make the serial->ps2 and cga->rgb adapters internal. I will update when more stuff get done 😊

Cool machine and nice restoration work! Never knew there was a Hyundai Pony PC like the car!

^ maybe they gave them away : got a Pony? here's the matching XT! 🤣 🤣 🤣

removed the ISA slot in question:

I think I'll also populate the last slot that for some reason is not soldered... the case has openings for 6 slots but only 5 are populated. I'll just add it along with the missing decoupling capacitor 😀

aaand done 😁
6 fully working ISA slots and a header on the back of the serial port in order to connect Matze79's serial->ps2 mouse adapter internally using it's dedicated pin header. I will install a ps2 port in a bracket along with the XTIDE serial port.

I also did a bit of a hackery in an old keyboard I had laying around: I noticed the shell had space for a XT/AT switch and that it was hard-wired to AT standard. So restoring the switch (SW1 under NumLock led) actually worked and now it supports both XT and AT connections. Inside the keyboard there is an Intel controller (above the arrow keys) and the keys are using microswitches for that soothing clickety-clack noise everybody loves 🤣

so today was a success 😊

ps. I wonder now if the "turbo" button above r-ctrl actually works 🤣

Wow, it's been a while since I last saw a turbo key 😀 Not to spoil it for you, but I think it was used in combination with the F-keys to set the repeat rate.

Can I just say that I find the dedication to your projects amazing? Well done! 😀

^ thanks 😁

@konc
really? I had no idea you could set the repeat rate like this, will test it

Keyboard update: turbo+F_keys does change the repeat rate of keystrokes 🤣
here are some pics with the XT/AT switch fitted , a very simple job:

Did some more work on the system, almost done!
I added a speaker volume control, ps2 mouse port and 15khz rgb-out using a custom bracket:

CGA ttl-out goes inside the machine to the cga->scart adapter , video gets converted and ends up at the blue port under the speaker volume control. Then with another custom cable I connect it via scart to a TV.
Mouse and Scart cables are shielded so there is no interference visible. Didn't want to shorten the mouse internal cable as it was a nice machine made one with great shielding, I'll just fix it somewhere or something 🤣
I will add a clone MPU in it and maybe the Lo-Tech 1MB ramcard so I can have some UMB's to load stuff 🤣 For now I am waiting for a 10mhz V20.

Did the V20 upgrade today , the system does feel snappier. The benchmarks don't show a huge difference but even simple stuff like dir command calculating free space is faster.
Most importantly some stuff that could not run before now work - don't think big 🤣 think something like EDIT.COM from DOS7x : with the 8088 the pc froze , now it runs fine 😀
I did lost the 1:1 4.77mhz speed though, with the V20 at low-speed 8088MPH now complains that there is a +16% speed difference. With the 8088 there was no such complain.

Here are some bench screens on high speed setting, interestingly sysinfo thinks the cpu runs at 16mhz 🤣

Beautiful work, as always!

What type of pot did you use for the volume control? Wattage, resistance?

thanks!
not sure about wattage (speaker is 0.25W IIRC so anything will work AFAIK) but I use a mono 1K logarithmic potentiometer.

A thorough and enjoyable thread and restoration - great job! Any case modifications expected?

thanks!
I haven't thought of doing any case modifications, can't really think of anything to add to it tbh... got any ideas?
Also realized I didn't post a pic yet of the complete case, so here's a pic with a crt tv that I use as a monitor until something better comes along:

the tv doesn't really fit... at least the display quality is really really good 🤣

That is a beautiful setup! I actually reread the whole thread 20 minutes ago, wanted to see the picture of the complete setup and was sad not to find any.