alexanrs wrote:

Are kits with the PC + components being sold anywhere or you have to order everything separately?

What are you exactly referring to?

The 1MB board, XT-IDE, etc. Lo-tech seems to be selling only bare PCBs... I believe there is also the EEPROM chips used on XT-IDE/XT-CF and the ROM board on his shop.

Yes Lo-tech only sell PCB's and you need to source the other parts yourself. Every board has a wiki page which includes a BOM (bill of materials) so that you can order from Farnell or Mouser, for instance. I order everything from Farnell because they have next day free delivery no matter how much you spend. Parts that were unavailable from Farnell i got from eBay. Lucky me it was just the 32DIP sockets.

The XT-IDE is pretty easy to assemble. The back side SMD components which are optional (but add useful extra functionality) need to be soldered with flux though, and i wouldn't recommend using cheapo chinese flux. I use a no clean EDSYN FL-22 syringe which is high quality flux but costs 16£ per syringe. 😵
But its high quality and a single syringe will last you a long time.

Can you easily source electronic parts in Brazil?

It depends on what parts, but I guess I should have no trouble sourcing enough for at least a ROM board (I have a Multi-IO with working IDE in 8-bit mode). Memory ICs for either an EMS or an 1MB board will be harder to get though.

EMS on an XT is really not very usable. You'd be better off with a RAM board that would allow you to use UMB's. Much more useful IMO.

The ROM board is very useful if you wanna place extensions at a specific address. You can even use XT-IDE with a normal 16bit controller. As long the IDE controller can use the standard ports 1F0h and 3F0h.

More progress today!

XT-IDE built:

The BIOS has now additional custom build pimpage, but it's nothing more than text...i forgot to take a picture of that however. I'll show it later.

TOP BENCH scores, first at 10MHz and 4.77MHz last:

Norton SI45 full speed:

Digger running in CGA mode on a OAK OTI-037:

NSSI info:

Now i couldn't get HD FLoppy BIOS working for some reason which also happened to bjt. This BIOS worked on my Juko motherboard so i have a theory why its not working, i just won't share it yet, i know i'll have it working eventually.

The OAK VGA is a slow VGA card and although its CGA emulation is decent, its image quality is subpar. So i want to try a Tseng Labs ET4000 and a Western Digital WD90C31 and decide between the 2.

Now the search for a proper desktop case!!

carlostex wrote:

Now i couldn't get HD FLoppy BIOS working for some reason which also happened to bjt. This BIOS worked on my Juko motherboard so i have a theory why its not working, i just won't share it yet, i know i'll have it working eventually.

Theory almost confirmed, one more test and i'll have to contact James about this.

Nice one, looking good!
Will be interested in your findings re HD floppy BIOS.

bjt wrote:

Nice one, looking good!
Will be interested in your findings re HD floppy BIOS.

Thanks i'm just waiting for something to arrive and i'll report. In the meantime my priority is to find a case. I also have an 8087 on route just because i can... I know it is almost useless but...why not?

Yesterday i tried a Goldstar Prime 2C MKIII multi I/O card and my grey Gotek has arrived:

Now the multi I/O card for some reason only works after a hardware reset. It's stupid but i can't get it to work on power on. A BIOS reset (CTRL + ALT + DEL) doesn't work either, so i have to use the RESET jumper. After i do it it finally works. When i power on, BIOS does not report any I/O ports being present, even though the multi I/O card is properly configured. After the hardware reset it finally detects the multi I/O and the high density floppy BIOS does its job:

Now this is NOT a system BIOS problem since i tried the original DTK ERSO BIOS this motherboard came with. The problem persists. I think i need a different multi I/O card.

So after always resetting the system after power on i can boot from a floppy drive, i could then play some games off of the Gotek:

I definitely want a different VGA here, i won 2 Tseng ET4000 on eBay for 1€ each, no one bid because the seller didn't have paypal, but since i can make bank transfers i got 2 of these cards for 6€ shipped! 😎

And as for case i think Kixs has at least 2 very interesting ones that seem to fit my requirements so this build is wrapping up really nicely.

Did you check if any part of the board is powered through the contacts on the 16-bit side of the ISA connector? Perhaps the board is having a hard time powering the controller in time for the BIOS detection routine (and AFAIK Ctrl+Alt+Del skips a bunch of things, unlike a proper reset).

Nah, it works if i do a hardware reset immediately after power on.

carlostex wrote:

Nah, it works if i do a hardware reset immediately after power on.

I'd still try soldering a few wires from the 16-bit 5V and ground lines to the 8-bit contacts. It could also be that the chip only reads the jumper settings imediately on power on and poor grounding (or 5V connection) might not be pulling down/up stuff fast enough for the chip to read. This is, of couse, just a somewhat educated guess.

That being said, the easiest thing to do to diagnose this would be testing it on a 286/386 system with both 8-bit and 16-bit slots, and see it you can reproduce the pattern - and if it only happens on an 8-bit slot. This, of course, only if you believe it is worth the effort, given that ISA controllers are cheap and plentiful.

Turns out i was wrong about HD FLoppy BIOS not working, it just becomes stuck because of the ISA controller, but works fine after a hardware reset. I thought that using 2MBit EEPROMS on XT-IDE board was the culprit but it turns out it wasn't.

Added a 8087 to the system. Damn thing runs too hot, i will definitely add a heatsink to it.

really like what I see!
so 8087s run hot eh? could be the reason why the old one fried...