Quick update/bump. I tested the motherboard, and it works fine. Sure, I couldn't boot because I have no floppy or HDD controllers, but I got to the POST screen with my CGA card (using composite, I do not own a CGA monitor), it recognized the memory I borrowed from a TGUI8900 ISA graphics card and complained about no floppy controllers and no KBD (no XT keyboard either). For the keyboard I bought the oldest thing I could find, and it is in good shape and the casing even had a hole for the AT/XT switch, but I guess this is a slightly newer revision without it, so I'm outta luck. Gotta build an AT2XTKB converter, but no big deal.

This is gorgeous. Thanks for sharing! And good luck. Looking forward to updates and photos of it running.

alexanrs wrote:

Could I use a more modern 16-bit multi-IO card? I assume IDE wouldn't work, but is that just due to the IRQs newer cards allow being too high? Or would these controllers be unable to operate without the higher data bits? If its just the IRQ, would soldering a jumper wire from, for example, IRQ15 to IRQ 3 or 5, provided the card has all ISA contacts, allow me to use the IDE ports (+XTIDE on a network card)? Also, is there any value to hunting down some ancient SoundBlaster for this thing, or would any SBPro compatibile non-PnP card be just as good for compatibilit with anything a XT can throw at it (OPL3 = 100% OPL2 compatibility, SBPro compatibility = 100% compatibility with ancient SB1/2 standards, etc.)?
Thanks!

I have a 16-bit multi-I/O card working perfectly in a XT-class machine, in a 8-bit slot of course, including fully functional 1.44M floppy support and IDE support for large drives. Details in this thread over at VCF (I am jh1523 there) http://www.vintage-computer.com/vcforum/showt … omponents/page4 starting from post #39

Basically I burned in an EPROM the BIOS extension from a 8-bit floppy controller, the KW-530D from here: http://www.minuszerodegrees.net/rom/bin/Kouwe … %20-%201987.bin and added it to the motherboard, that gave me support for 1.44M floppies; in another EPROM I burned the universal XT-IDE BIOS configured for an 16-bit IDE controller operating in 8-bit mode, and that allowed the IDE controller on the I/O board to function. I'm very happy with the setup.

If you look at the picture of my motherboard at the beginning of the thread you will see that I had 3 empty EPROM sockets, that's where I placed the extensions; I see you have 1 empty socket that looks like it's for an EPROM, not sure what address it would be mapped to though (anything from C800 to F400 should work) Otherwise you could use a NIC boot ROM socket, or one of these: http://www.lo-tech.co.uk/wiki/Lo-tech_ISA_ROM_Board

I wouldn't consider a sound card a must for an 8088 machine. the first sound card and games that support it didn't appear until the later half of the 1980's past this machines prime. That being said I have a Sound Blaster 1.5 with CMS chips in my 8088 machine.

That trident card you have is actually 8-bit compatible and should work in that motherboards 8 bit slots as a VGA card.

brassicGamer wrote:

This is gorgeous. Thanks for sharing! And good luck. Looking forward to updates and photos of it running.

Thanks... it will be a while till I can get everything running, though =/
Btw, for anyone that has the means to buy stuff in Brazil, this things are going for under US$15 here.

stamasd wrote:

I have a 16-bit multi-I/O card working perfectly in a XT-class machine, in a 8-bit slot of course, including fully functional 1.44M floppy support and IDE support for large drives. Details in this thread over at VCF (I am jh1523 there) http://www.vintage-computer.com/vcforum/showt … omponents/page4 starting from post #39

Basically I burned in an EPROM the BIOS extension from a 8-bit floppy controller, the KW-530D from here: http://www.minuszerodegrees.net/rom/bin/Kouwe … %20-%201987.bin and added it to the motherboard, that gave me support for 1.44M floppies; in another EPROM I burned the universal XT-IDE BIOS configured for an 16-bit IDE controller operating in 8-bit mode, and that allowed the IDE controller on the I/O board to function. I'm very happy with the setup.

If you look at the picture of my motherboard at the beginning of the thread you will see that I had 3 empty EPROM sockets, that's where I placed the extensions; I see you have 1 empty socket that looks like it's for an EPROM, not sure what address it would be mapped to though (anything from C800 to F400 should work) Otherwise you could use a NIC boot ROM socket, or one of these: http://www.lo-tech.co.uk/wiki/Lo-tech_ISA_ROM_Board

Oooh, so it doesn't need the IRQ?! Thats good news. I"ll get one of those cheap ISA multi-IO cards then, with FDD+IDE+GamePort+2 COM+LPT. These should be more ports than this 8088 will ever need.

soviet conscript wrote:

I wouldn't consider a sound card a must for an 8088 machine. the first sound card and games that support it didn't appear until the later half of the 1980's past this machines prime. That being said I have a Sound Blaster 1.5 with CMS chips in my 8088 machine.

That trident card you have is actually 8-bit compatible and should work in that motherboards 8 bit slots as a VGA card.

Yeah, but currently it is not working (I removed half of its RAM to test the 8088). Also, I kindda wanna use my full-length CGA card that is three times the size of this motherboard xD

alexanrs wrote:

Oooh, so it doesn't need the IRQ?! Thats good news. I"ll get one of those cheap ISA multi-IO cards then, with FDD+IDE+GamePort+2 COM+LPT. These should be more ports than this 8088 will ever need.

There's a caveat though. The serial, parallel, game and floppy ports did indeed work on all I/O cards I tried (I have a small stack of them). The IDE port was a little fussier, it didn't work on all of them. Of all the Winbond chipset cards I tried only one would have the IDE port working correctly, and even then it was unreliable. OTOH most UMC chipset cards had the IDE port working correctly and reliably with the XT-IDE bios.

But of course YMMV.

That looks like one of the latest XT mobos , judging from size and integration. I think the best trouble-free option would be an IDEXT card - you can use something simple as this: https://www.lo-tech.co.uk/product/lo-tech-isa … mpactflash-pcb/

The thing is I will get a multi-IO regardless, since I need the FDD controller anyway. So if I can get it working I'll need just that one card instead of two to get IDE too.

Btw, stamasd, do you know how a Goldstar Prime 2C would behave? I see one locally for under US$10, half of the price of the rest, and it looks decent.

Sorry, I've never tested that board because I don't have it. I'd say it's worth a try.

Scanned and added a proper PDF to the first post. Btw doesn't Vogons have a strikeout text tag?
Also, stamasd, I will buy that controller. Just need to wait for the seller to answer if he can combine shipping with another item he has that I want. I'll also FINALLY buy an EEPROM programmer (and probably go on a backup spree - eg. I have a 486 mobo with an UV-erasable EPROM and I have no backup of that BIOS) and a few EEPROM chips. 😀

For EPROM/EEPROM programming I recommend a TL866. It's USB, has support for many chips and the software and firmware are updated quite frequently. I paid about $50 for mine a couple of years ago on ebay, because I wanted the full-fledged one with ICSP port. If you don't care about that you can find the model without ICSP for $30 or even less. Mine also included a bunch of adapters for various packages, SOIC/TSOP/QFP etc.

http://www.autoelectric.cn/EN/TL866_main.html

I'm debating whether I should buy it in Brazil for R$250 (US$65) and get it fast and for a set price or try my luck buying it from China either on eBay or AliExpress for US$35-40 (R$140) but risk it taking months to arrive, dealing with customs and gambling with the dollar exchange rate (used to be under 2.7 by this time last year, now it is 3,8).

Btw, would a W27C257 be compatible with the 27256 the board requires?

alexanrs wrote:

Btw doesn't Vogons have a strikeout text tag?

Nope! 😀

alexanrs wrote:

Btw, would a W27C257 be compatible with the 27256 the board requires?

I looked at the datasheets, I think so.
http://www.romservice.ru/datashee/w27c257-a2.pdf
http://esd.cs.ucr.edu/webres/27c256.pdf

I already ordered the TL866, two W27C257 and I'm planning on building the AT2XT keyboard converter as well. I just have a quick question: what kind of case should I use? I was thinking of putting my K6-2 on an ATX case (it is one of those baby-AT/ATX "combo" motherboards that can accept both types of PSU), my Pentium on the K6-2 case, then my 486 on the Pentium case and this board on the 486 case... but I can't help but think things would look kindda "wrong". How would a late turbo 8088 from 89 usually look like?

alexanrs wrote:

How would a late turbo 8088 from 89 usually look like?

Hi Alexanrs! Great purhcase, very beautiful board. You have a lot of work to do before you could enjoy a fully running system, but believe me - it`s worth the effort ! From my point of view, an ideal turbo XT clone computer case should look like this (see this sexy power switch on the side?? 😀 :

I remember this case design from advertisements in late 80`s polish computer magazines. Some of my friends had XTs in such cases back then. They look very unique when combined with a small hercules monitor. I`m going to move my XT machine into similar case as on the picture, because, as you`ve said - the system would look wrong in an unproper case 😀

ciernioo wrote:

Hi Alexanrs! Great purhcase, very beautiful board. You have a lot of work to do before you could enjoy a fully running system, but believe me - it`s worth the effort ! From my point of view, an ideal turbo XT clone computer case should look like this (see this sexy power switch on the side?? 😀 :

I remember this case design from advertisements in late 80`s polish computer magazines. Some of my friends had XTs in such cases back then. They look very unique when combined with a small hercules monitor. I`m going to move my XT machine into similar case as on the picture, because, as you`ve said - the system would look wrong in an unproper case 😀

Thanks! Yeah, that looks like a case that would match the hardware. I'll be watching Brazil's local "ebay" until I find something like that. In fact, I remember seeing a case somewhat like that (except the power switch on the side) a few months ago, but I did not have the board back then, so I did not think about buying it.

This is a beautiful late turbo XT board you have here.
Please keep it real and use it with 8-Bit cards. Don't waste 16-Bit trash in this true 8-Bit beauty. (Jaja, I know 16-Bit cards are no trash but in a genuine XT class machine one uses the real cards.)
Who cares if 16-Bit cards run in the 8-Bit slots if decent 8-Bit cards are still available?
For example a decent Sound Blaster clone sound card with a true OPL2 chip and volume wheel is available for a bit more than 40 USD and so are graphics cards.

FGB wrote:

This is a beautiful late turbo XT board you have here. Please keep it real and use it with 8-Bit cards. Don't waste 16-Bit trash […]
Show full quote

This is a beautiful late turbo XT board you have here.
Please keep it real and use it with 8-Bit cards. Don't waste 16-Bit trash in this true 8-Bit beauty. (Jaja, I know 16-Bit cards are no trash but in a genuine XT class machine one uses the real cards.)
Who cares if 16-Bit cards run in the 8-Bit slots if decent 8-Bit cards are still available?
For example a decent Sound Blaster clone sound card with a true OPL2 chip and volume wheel is available for a bit more than 40 USD and so are graphics cards.

I know! It is beautiful and compact! About keeping it real, I have a true 8-bit CGA clone and I don't think I'll put a sound card for now. The only issue is the multi-IO cards. Can't find 8-bit controllers easily, so it might "taint" the build for a while, but other than that its 8-bit card time!