Yes i did try it on an AT again and it has the same behaviour, keyboard lights flash when the system is turned on, but does not work anymore.

I also still have to try the XT-IDE board with an ATA-2 compliant hard drive, the COmpact Flash cards i have are not being detected. Maybe its the adapter?

This is really infortunate, not having a working keyboard is stopping me in my tracks. I really need to go for a good quality XT keyboard.

Invest in an AT to XT keyboard converter by chuck(g) on vintage-computer.com

I guess that's the most sensible solution. I've done well soldering the XT IDE Board, i believe that using good solder flux makes all the difference. I've never took a good look on the converter design but it should be a rather simple hack job.

I've finally managed to get my XT-IDE card recognizing the drives. My error was not to use a pre configured BIOS. I used BIOSes from the XT-IDE site project and those probably need to be configured first.

I glued High Density Floppy BIOS support to the XT-IDE BIOS, so XT-IDE starts at C800h and HD Floppy BIOS starts at CA00h if i'm not mistaken. There's still room in the EEPROM for 16kb more of BIOS extensions should i need them.

Now i just need either to get a new XT keyboard or invest in a converter. However i've not read yet through all the VCF thread pages about it, and it mostly seems that i need to order PCB and parts to build it myself. It could be that there are no more PCB's available and a new production run is needed. If so this could be much more expensive than getting a new keyboard.

Tandy Enhanced Keyboards with a 5 pin DIN connector are interesting and from what could i understand are XT-AT autoswitching. At this point i'd rather prefer something i'm sure to work well, which would be of course a native XT keyboard.

I also need to get a 27C64 compatible EEPROM to replace the 2.20 Juko BIOS by the newer 2.30 version.

All in all at least i'm happy that the system boots and now i have both IDE and High Density Floppy support available from boot time. I also have plenty of cards that seem to work OK in 8bit mode. An OAK OTI-067, Trident 8900C, Tseng ET3000 all worked great in an 8bit slot. And i still have a few others i had no more time to test.

Also need to find a desktop style AT or XT case so i could fit this system in. Looks like i'll take at least another year minimum to finish this system.

What are the changes from V2.20 to V2.30?

Anonymous Coward wrote:

What are the changes from V2.20 to V2.30?

Good question, i have no idea. This is just something i want to try. And i want to have EEPROMS ready just in case. There shouldn't be a big difference between the 2.

I've been thinking about the Tandy Enhanced Keyboard which seems to be a realy nice keyboard to use with an XT. I just gotta find an afffordable one. I would prefer an IBM Model F but these are extremely expensive these days.

So far the board seems reliable working at 12MHz. A NEC V20 at 12MHz can be quite a snappy system (for an XT that is), and i still have a jumper to set memory waitstates. At 4.77Mhz the system is slow enough to mimic an IBM XT. Even speed sensitive games that were made for an 8088 running at 4.77Mhz should be playable enough for my enjoyment. Which reminds me, i got some questions to ask around here...

I have a Juko 8086/V30 board. It uses something called "NEST" BIOS. I would imagine it should work on a 8088/V20 board if you were to convert the BIOS into a single 8-bit image. (16 bit boards use two 8-bit ROMs). It would be interesting to compare to what you have to see if it is newer or older. I do not recall mine being particularly great. Does not support high density floppies or enhanced keyboards (as far as I can tell). I also got a copy of a Phoenix BIOS from a CompuADD 810 8088 that supports high density floppies. If you want to try it out, I can send it to you. XT BIOSes are generally interchaneable...but as these Juko boards use VLSI technology I have no idea if it would work or not.

Unfortunately I have not been able to get my Juko V30 board running recently. It may have been damaged during shipping....or perhaps it just didn't like the power supply I threw at it. I moved from a 115V country to a 230V country, and I can't use my original XT power supply which is not switchable. Do XT motherboards require XT power supplies?

Thanks, but i wouldn't be able to try it until christmas. The reason is that i live on the UK and my XT stuff is at my folks house in Portugal I get a chance to play around with the stuff when i'm on vacation there.

I'm pretty happy that i was able to do everything with the XT-IDE board not only for IDE support but also to provide HD Floppy extensions. I seriously doubt your problemscome from the power supply, unless the rails are not providing proper voltage. Have you tried checking with a multimeter? You can go as far as trying an ATX PSU with an adapter. In fact that's what i did and it works perfectly fine. AFAIK AT PSU's work on XT motherboards fine, the pinout is the same.

My concern at the moment is the keyboard, the Tandy Enhanced Keyboard seems to be XT compatible but at this point i feel like not taking a risk. IBM model F's are just too freakin' expensive. I couldn't understand if i have to order a PCB to build an XT to AT converter, or if i can order a complete assembled one. On eBay i see keyboards that are listed to be XT compatible and come with WIndows keys and PS/2 interface 😒 i'll probably be luckier with an ad on amibay.

All in all i'm pretty excited with building an XT, it's really the last machine i need to build to cover all DOS games. My Socket 7 build pretty much covers everything else just fine.

EDIT: I'm wondering if there's any kind of BIOS extension for AT keyboard support on an XT. That's all i would actually ever need. I still have 16kb available in the XT-IDE EEPROM, and gluing the HD Floppy BIOS was so successful that i don't see a reason why a BIOS extension wouldn't work. I just need to find one, or write my own...

I don't think it's possible to hack an AT keyboard onto an XT with a BIOS extension. It's a hardware problem, different controllers.

So i presume that the 2 are electrically incompatible?

carlostex wrote:

...What am i missing then? - A 8bit VGA card with good CGA and EGA compatibility, true CGA and EGA is out of the question, Serge […]
Show full quote

...What am i missing then?
- A 8bit VGA card with good CGA and EGA compatibility, true CGA and EGA is out of the question, Sergey Kisilev's card would be perfect:

Any informations about the quality of the signal on a normal 15" TFT Monitor?
Any informations about drivers for win1x,win2x,win3x, GEM, Autoxad etc.?

I tested about 80 ISA graphics-cards on my 15" NEC-TFT and only a 3-5 produce a good and relatively sharp image on the TFT.
mostly there are vertical lines on greater spaces with the same color visable.

mostly "premium-manufactures" like diamond have better image-quality then no-name stuff with the same chipset.

dr.zeissler wrote:

mostly "premium-manufactures" like diamond have better image-quality then no-name stuff with the same chipset.

That mostly has to do with the design and choice of components (lower tolerance) of the low-pass output filter after the RAMDAC.
If you build the card yourself, you can choose good quality components, and you should get 'premium' quality output. You could also modify an existing card yourself.

Choosing a lower refresh rate should also improve image quality on cheap cards. A poor filter will have less effect on the signal when the resolution and/or refresh rate are lower, because the whole signal will have less high-frequency components.

Hi dude, was wondering where you got your HD floppy BIOS from?
I have it kind of working at the moment, but it autodetects the Gotek as a 720k drive.
Was thinking to hack it to force 1.44MB A and 360k B.

bjt wrote:

Hi dude, was wondering where you got your HD floppy BIOS from?
I have it kind of working at the moment, but it autodetects the Gotek as a 720k drive.
Was thinking to hack it to force 1.44MB A and 360k B.

https://www.lo-tech.co.uk/wiki/Lo-tech_8-bit_ … Board#8-bit_IDE

carlostex wrote:

I've finally managed to get my XT-IDE card recognizing the drives. My error was not to use a pre configured BIOS. I used BIOSes from the XT-IDE site project and those probably need to be configured first.

I had the same adventure recently - I`ve lost 2 weeks before I realized my mistake. I even ended up with second IDE card built, as I thought something broke in the first one 😀 Well, RTFM they say ... Anyway, congratulations with the progress, Hope you`ll get your machine together soon. I love XTs, nothing beats the feeling of building and running one 😀

carlostex wrote:

Since i came to live in the UK the retro bug never stop biting. I actually miss the stuff. I'l pllaning a super socket 7 build f […]
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Since i came to live in the UK the retro bug never stop biting. I actually miss the stuff. I'l pllaning a super socket 7 build for which i already got a motherboard for. This will be my main time machine here in England.

In the mean time i always wished for something pre 386. I do have a 286 motherboard, but i always wanted to build a turbo XT system. Actually i would prefer a Tandy 1000, but ordering one from the US will cost an arm and a leg not to mention customs headaches. I will love getting around the technical difficulties of the XT 8bit bus. I'm still gathering parts to assemble this build and i'm gonna assemble it when i return to Portugal on vacation.

This is the board i got:

I also got a Multi I/O card including Parallel, Serial, Gameport and Floppy controllers and a CR2032 holder for a RTC:

I also have a MIDIMAN MM-401 card to provide an intelligent MPU-401. I just need the adapter cable. I will also be using a Sound Blaster CT1320C with CMS chips, or a 1987 AdLib and a true Game Blaster card.

What am i missing then?

- A 8bit VGA card with good CGA and EGA compatibility, true CGA and EGA is out of the question, Sergey Kisilev's card would be perfect:

Although i'd rather ask him to build it for me, my soldering skills are not legendary...

I will also need XT-IDE or XT-CF, something i will probably get out of James Pearce XT-CF-lite or Sergey's version of that.

One thing that i noticed is the power socket for the AT P8 and P9 connectors is quite weird, will a normal AT PSU work well with this board and that kind of connector?

Anyway, any advice regarding this build is welcome. My experience with XT systems is rather limited.

WOW Sergey Kisilev can make his own isa cards? That is so cool! I'd love to talk to him! 😀

Is there any progress on this build? I really love to see the next choices you are going to make.

My build on the V20 Nec halted some time ago.. Not because iam lazy to going further with it..
Because i have a painting problem with my case iam going to use..
The underside was rusty, so i cleaned it up to the metal of the case.. Now i want to do a restore job..
But i really dont know what would be the best choice of the type of paint to use.. I know i can buy a spraycan in the store..
But i really dont think that kind of paint would last long.. Also it wouldnt be protected much against bumps (so actually the paint could come off)
I know that the standards of coatings / paint back in the day where much better..

Robin4 wrote:

Is there any progress on this build? I really love to see the next choices you are going to make. […]
Show full quote

Is there any progress on this build? I really love to see the next choices you are going to make.

My build on the V20 Nec halted some time ago.. Not because iam lazy to going further with it..
Because i have a painting problem with my case iam going to use..
The underside was rusty, so i cleaned it up to the metal of the case.. Now i want to do a restore job..
But i really dont know what would be the best choice of the type of paint to use.. I know i can buy a spraycan in the store..
But i really dont think that kind of paint would last long.. Also it wouldnt be protected much against bumps (so actually the paint could come off)
I know that the standards of coatings / paint back in the day where much better..

Actually there is progress. My XT build here in England will be based on one of 2 motherboards i have documented here. The Juko one (on this thread) and the TB10 board from (Yet another XT build) thread. This Juko board is slightly faster, pretty fast for an XT. If everything works great and is stable i'll use the Juko, if not the other one is a great mobo too. So far the Juko board is working great.

I'm trying to do something special with this build. As i write this the case for this build is on my way. I should post a lot of pictures after the system build process. Next week for sure.

I want to use 8bit cards exclusively for this build, but this is a goal that might take me some time to achieve completely.
Cards to use are:

1 - XT-IDE built by myself with Sergey's HD floppy BIOS at C600h to C800h range and XT-IDE BIOS at C800h to CA00h, with 16kb available in the EEPROM;
2 - Western Digital Paradise PVGA1A. I have a 16bit one, but i want to get the smaller 8bit one. Excellent CGA compatibility;
3 - Creative Sound Blaster 2.0 with CMS upgrade;
4 - Generic Floppy / IDE controller, supports HD floppy data rates;
5 - Multi I/O, Floppy, RTC card, similar to the one picture on first page, had to remove 8397 chip to avoid floppy conflicts. Works with PC TIMER;
6 - MIDIMAN MM-401 MPU-401 MIDI interface;

Still have 2 slots left. Options include:

1 - Possibly a network card to use mTCP; (not really a big wish)
2 - EMS card or preferably RAM card to use UMB's; (useful)
3 - Tandy 3 voice sound card; (waiting for James Pearce to prototype the design)

I would also love to have an IOMEGA ZIP 250 on there but XT-IDE CF adapters don't support ATAPI as far as i know...

I got my Juko V30 motherboard going again.

I finally got a chance to test the CompuAdd 810 BIOS on it, but unfortunately it does not work. I suspect our Juko boards can only use Juko XT bioses. I'm wondering if your V2.30 BIOS can work in my board. When you have time, please send me a copy.

No problem in sending you the BIOS. I doubt it will work though. It's this one.

Your board seems to need a BIOS EVEN/ODD, those are probably 2 27C64 8kb EPROMS.

BTW, other BIOS'es work fine with my Juko board.

I would like to also find a 8086 board, but these are really hard to find. Usually 8086 systems were mostly OEM designs with stuff integrated in proprietary form factors. That sucks.

I'm hoping that someone designs a custom Turbo XT double or triple clock circuit. I already gave my idea to James Pearce from lo-tech and he liked the idea. With time i'm sure he will be able to pull it off. I would like to see a triple clock setting like 4.77/10/16 Mhz selectable. The 16Mhz would be only selectable if you have a V20/V30HL. I imagine a V20 at 16MHz could be close to a IBM 5170. And a V30 at 16Mhz could probably beat it.

Now about the build... The case i got from Kixs arrived today! Awesome case, it is close to perfect. It's a bit deep but fits my desk very well. I need to clean it and i will be putting the system together later today. Pictures to come as well.