keenerb wrote:

Not seriously. I couldn't find sockets that worked with the resistor arrays well, so I never went any farther with the active terminator.

I had some, but I have no idea where they came from. It was a long (30-pin?) SIP socket that I was able to cut into resistor-size sections. I've attached a picture of one of the leftover pieces.

Given that I often ordered parts from Jameco around the time this SIP socket strip fell into the parts bin many years ago, it's quite possible this one, though I couldn't guarantee it: https://www.jameco.com/z/SMC-1-30-1-GT-Adam-T … Tail_78642.html

I still plan on playing with resistor values to see if lower or higher values impact my stability. Regardless, I don't think the terminator board is the "the fix". It's treating the symptoms in some way, but isn't treating the cause. I'd like to throw a logic analyzer on this thing and see if there's something weird with gate delay that just isn't obvious from staring at the schematic.

In the USA another good source for SIP sockets suitable for use with resistor networks/arrays is Tayda Electronics at http://www.taydaelectronics.com/connectors-so … older-type.html

They don't have a huge variety of components but from what I have seen their quality is decent and the prices for what they do have is fairly reasonable. There shipping charges are also quite low.

I am still gathering components to build my Xi 8088 so I haven't been able to do any testing yet.

For anyone who is interested, it looks like Sergey has started a new project in a thread over at the retrobrew forum, that uses a FE2010A to replace many of the x86 support chips -- interrupt controller, dma, timer, etc. The prototype schematic also includes buffering of the SRAM chips.

It looks like there are a few limitations compared to the Xi 8088. For example, the board only implements up to 640 KB of RAM.

smbaker wrote:

For anyone who is interested, it looks like Sergey has started a new project in a thread over at the retrobrew forum, that uses a FE2010A to replace many of the x86 support chips -- interrupt controller, dma, timer, etc. The prototype schematic also includes buffering of the SRAM chips.

It looks like there are a few limitations compared to the Xi 8088. For example, the board only implements up to 640 KB of RAM.

Yeah, I stumbled across a "hidden" page with a basic schematic for that a while back. I was hoping we could figure out what was up with this board so he could incorporate it into his new device...

hidden? its all in his github.

https://github.com/skiselev/micro_8088

the note at the bottom is interesting;

AS6C1008 (U6) does not have TTL compatible inputs causing instability with 640 KiB memory configruation

Workaround use CMOS transceiver U11, e.g. 74AHCT245

Yeah, I came across this a long time ago:

http://www.malinov.com/Home/sergeys-projects/xi-8088-cpld

I couldn't find it linked anywhere from his main page, but Google had indexed it.

I talked to Sergey about it a few times, he said he was revisiting it, looks like he dropped the CPLD in favor of the FE2010 chip.

That is an amazingly small board.

keenerb wrote:

I talked to Sergey about it a few times, he said he was revisiting it, looks like he dropped the CPLD in favor of the FE2010 chip.

That's a very interesting find. While the CPLD would have replaced a lot of the small glue ICs, I think any such design would have still had the larger support ICS (8254, 8253, 8259, etc). Still, would have been cool to see it actually completed.

BloodyCactus wrote:

the note at the bottom is interesting;

Over on the retrobrew thread, it's been speculated (but not yet tested) that a second AS6C4008 could be used instead.

I already picked up a few FE2010A ics...

keenerb wrote:

I already picked up a few FE2010A ics...

🤣, me too. I figured I better have a few on hand just in case they're hard to find when I need them.

I just had a wild idea... The new CPU card is short enough that one could conceivably combine the CPU card, VGA card, and XT-IDE card into one (expensive) full-length card.

Scott

I think he should merge his projects into one single board, an all-in-one integrated 8088 motherboard. Floppy controller, ide controller, video card, sound card, cpu card, Isa slots. Would be a nightmare to trace probably...

Hello, I'm new to the Vogons. Since I'm building and enjoying this hobby, I thought I should join the community.

I recently built the Xi 8088 cpu card and the malinov backplane. Still waiting for parts for the video, floppy, cf and opl2 cards.
Currently the system is booting using a Trident based Jaton video card and a Pine controller card. I can boot dos using a floppy disk no problem however, I can't get the ide to work.
I did check that the ide was enabled and tried changing the ide address jumper settings on the controller card but the same. Not too worried about the ide since I am building the cf card, just wondered if anyone knew why I could boot from floppy but it doesn't see any hdd.

Video Card:
http://stason.org/TULARC/pc/graphics-cards/I- … -JAX8216-T.html

Controller Card:
http://stason.org/TULARC/pc/hard-disk-floppy- … s-AI-1078E.html

On another note,
Has anyone found what was causing the stability issues a few people have had? I haven't had any problems like that yet but I'm very curious what the root cause was. For my build I basically used all the recommended parts from mouser, UT source and Unicorn electronics.
NEC v20 CPU and 8087-2

Lastly,
I watched smaker's youtube video of his Xi 8088 and I was wondering if there are different (newer) bios versions for this board? My boot selection looks different than the one in the video.
https://www.youtube.com/watch?v=MW5lApN0gWc&t=2286s

The bios I'm using is 0.9.0 bios128k-xtide-2.0.bin from Segey's website.
http://www.malinov.com/Home/sergeys-projects/ … redirects=0&d=1

Sir Isaac wrote:

Currently the system is booting using a Trident based Jaton video card and a Pine controller card. I can boot dos using a floppy disk no problem however, I can't get the ide to work.
I did check that the ide was enabled and tried changing the ide address jumper settings on the controller card but the same. Not too worried about the ide since I am building the cf card, just wondered if anyone knew why I could boot from floppy but it doesn't see any hdd.

It is possible that the controller card you are using isn't compatible with the (quite old) version of the XTIDE option ROM that you flashed. This is especially likely if the controller card you are using has it's own ROM chip. Try reflashing the Xi BIOS using the image without the XTIDE ROM and see if your controller card works after that.

When you get your XTIDE card built, I recommend using the latest XTIDE release available at http://www.xtideuniversalbios.org/binaries/ instead of the one on Sergey's website The current XTIDE option ROM has several fixes which make it compatible with more CF cards than the relatively old version that Sergey embedded in the Xi BIOS.

I made updated BIOS and updated the xtide bios inside it as well.

this is the last one I did, it incorporates the xtide boot menu

https://github.com/stu/xi8088_bios/blob/0.9.1 … -xtidel-2.0.bin

BloodyCactus wrote:

I made updated BIOS and updated the xtide bios inside it as well.

this is the last one I did, it incorporates the xtide boot menu

https://github.com/stu/xi8088_bios/blob/0.9.1 … -xtidel-2.0.bin

Awesome, that's the one in the video. The date is displayed properly now. Thank You

wbo wrote:

Sir Isaac wrote:

Currently the system is booting using a Trident based Jaton video card and a Pine controller card. I can boot dos using a floppy disk no problem however, I can't get the ide to work.
I did check that the ide was enabled and tried changing the ide address jumper settings on the controller card but the same. Not too worried about the ide since I am building the cf card, just wondered if anyone knew why I could boot from floppy but it doesn't see any hdd.

It is possible that the controller card you are using isn't compatible with the (quite old) version of the XTIDE option ROM that you flashed. This is especially likely if the controller card you are using has it's own ROM chip. Try reflashing the Xi BIOS using the image without the XTIDE ROM and see if your controller card works after that.

When you get your XTIDE card built, I recommend using the latest XTIDE release available at http://www.xtideuniversalbios.org/binaries/ instead of the one on Sergey's website The current XTIDE option ROM has several fixes which make it compatible with more CF cards than the relatively old version that Sergey embedded in the Xi BIOS.

I tried the bios without the XTide support and still no luck. I'll just have to wait for my cf card parts. Thanks for the heads up regarding XTide rom bios. I'll be sure to use the one you linked.

A few more questions,
What does the SW3 - I/O Wait States switch do? Tried changing which one is toggled, didn't seem to do much.

I was also trying to get the turbo mode working. On the boot screen it always shows "Turbo OFF" no matter how the jumpers are positioned on JP2.

I'm using the 0.9.1 bios128k-xtidel-2.0.bin BloodCactus posted from here:
https://github.com/stu/xi8088_bios/tree/0.9.1

if your quick in bootup with the ctrl-alt-+ it will go into turbo mode.

youll know if turbo is working or not by the speed of the ram count.

the turbo disiplay is based on the io port status, jumpering turbo to on may not change that status bit, so it may not display correctly in that mode (nothing I can do about that).

BloodyCactus wrote:

if your quick in bootup with the ctrl-alt-+ it will go into turbo mode.

youll know if turbo is working or not by the speed of the ram count.

the turbo disiplay is based on the io port status, jumpering turbo to on may not change that status bit, so it may not display correctly in that mode (nothing I can do about that).

Ah, very cool. that works

Has anyone gotten any kind of high memory or extended memory to work yet? On Segey's site it says 832 KiB of usable system memory. Curious how that works. Do you need to load something like himem.sys in dos 6.22? Is it possible to extend the ram more? Even by means of an add on card?

you can use something like use-umbs.zip, you have to hexedit your address range into it or compile it and this will put ram into the c000 etc range.

BloodyCactus wrote:

you can use something like use-umbs.zip, you have to hexedit your address range into it or compile it and this will put ram into the c000 etc range.

Interesting, I'll have to research that.