VOGONS


Xi 8088 by Segey Kiselev

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Reply 521 of 613, by smbaker

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Result of my weekend testing... Krynn ran solid for approximately 48 hours until I shut it down this morning. This is using the "4GB Top Ram" card that Sergey recommended. Swapped one of my old 64 MB cards back in and it failed within an hour. So I'm pretty confident in concluding that my system, as configured with CF + Micro 8088 + VGA, is stable with the Top Ram card and unstable with the older 64 MB card.

Reply 523 of 613, by keenerb

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smbaker wrote:

Result of my weekend testing... Krynn ran solid for approximately 48 hours until I shut it down this morning. This is using the "4GB Top Ram" card that Sergey recommended. Swapped one of my old 64 MB cards back in and it failed within an hour. So I'm pretty confident in concluding that my system, as configured with CF + Micro 8088 + VGA, is stable with the Top Ram card and unstable with the older 64 MB card.

Also, it would be a hell of a thing if the xi8088 worked fine with the 4GB Top Ram" card.

You have a link to the card you purchased?

Reply 524 of 613, by keenerb

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keenerb wrote:
Honestly, this is some weird shit. […]
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Honestly, this is some weird shit.

I think my Malinov FDC may be toast, it's not working in my Tandy either.

My machine only boots from a Magitronics floppy adapter, IF my Gotek is configured for S0 (first drive), but on the second drive connector.

If I use an XT-IDE controller configured at C800, it can't boot from floppy drive.

If I use an XT-IDE controller with rom at CA00, it boots, but keyboard doesn't work.

Pretty f*cking ??? if you ask me.

My malinov card definitely seems to be on the fritz; doesn't work in my Tandy TL either now, when I know it used to. My generic controller works fine there, so that is one mystery solved.

Still not sure why my gotek boots as A when jumpered for S0 on the middle connector of the cable; isn't the far end supposed to be drive 0? Maybe this is a funky cable as well.

Reply 525 of 613, by smbaker

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keenerb wrote:

You have a link to the card you purchased?

https://www.ebay.com/itm/TOPRAM-4GB-CF-4G-Com … se/321094265100

Also available at newegg: https://www.newegg.com/Product/Product.aspx?I … =9SIA12K0932498. (not sure why I went the eBay route as it was a dollar more expensive)

keenerb wrote:

What XT-IDE build are you using?

Looks like I am running version 2.0.0b3+

Scott

Reply 526 of 613, by keenerb

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I have always had some sort of weird problem with ide on Sergey's stuff. I wonder if the LoTech xt-ide cards have a compatibility problem. Which IDE adapter are you using, SMBaker?

I also picked up an IDE disk-on-module to tinker with, they seem to be really cheap on Ebay.

Reply 527 of 613, by smbaker

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keenerb wrote:

Still not sure why my gotek boots as A when jumpered for S0 on the middle connector of the cable; isn't the far end supposed to be drive 0? Maybe this is a funky cable as well.

Floppy cables are weird. My understanding is floppies are usually jumpered to respond as drive 1, and the split+twist before the last connector swaps the drive 0 and 1 signals.

keenerb wrote:

I have always had some sort of weird problem with ide on Sergey's stuff. I wonder if the LoTech xt-ide cards have a compatibility problem. Which IDE adapter are you using, SMBaker?

I'm using Sergey's adapter. The Lo-Tech adapters do have a data buffer whereas Sergey's adapter does not. I've speculated that may be allowing ill-behaving compactflash devices to mess impair the bus.

Reply 528 of 613, by smbaker

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I've had some developments:

1) I built a new backplane using 30-microinch gold plated edge card connectors

2) I put the Xi 8088 back in to do some stability tests

I was able to run Champions of Krynn for about 36 hours without incident until I had to clear the workbench to make room for another project. This is still a minimal expansion card configuration, so at some point I'm going to start adding more cards back in. I do feel that I had a backplane issue before, especially considering I often had to jiggle cards after they had been sitting for a while.

Reply 529 of 613, by keenerb

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smbaker wrote:
I've had some developments: […]
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I've had some developments:

1) I built a new backplane using 30-microinch gold plated edge card connectors

2) I put the Xi 8088 back in to do some stability tests

I was able to run Champions of Krynn for about 36 hours without incident until I had to clear the workbench to make room for another project. This is still a minimal expansion card configuration, so at some point I'm going to start adding more cards back in. I do feel that I had a backplane issue before, especially considering I often had to jiggle cards after they had been sitting for a while.

I've been running for two days now with a full backplane (micro8088, Malinov floppy controller, 2mb EMS card, ethernet card, Soundblaster, Adlib, Tandy, and EGA card) and it's had no problems.

I feel pretty good about this. I'm abandoning compact flash adapters for full XT-IDE card + disk-on-module.

Reply 531 of 613, by keenerb

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Apparantlyy vga card was generating the nmi interrupts. I switched to a vga card and it is fine now.

The floppy adapter was a combo ide/floppy with some unidentified jumpers; it worked but out if an abundance of caution I fixed my malinov card.

I still have cf card issues but right now I am simply booting and running from floppy.

Reply 532 of 613, by opticpow

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Hi Gents,

I've just finished reading this thread (yes it took a few days!). I have just finished my Xi-8088, and have finally got it working. It's nice to see other builders. I'm also keen to experiment and I'm happy to help out with testing if you need another metric.

Currently I have:
Xi-8088 with V20 & 8087
Sergey's Backplane
N8VEM floppy controller with Sergey's ROM & 3.5 & 5.25 Floppy drives
Trident TGVA9000 off ebay until I build one

On The todo list:
Sergey's VGA Card,
XT-IDE,
Sergey's Ablib clone

Reply 534 of 613, by sandraos

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Hello Vogons:

New to this forum. Great idea this forum is for us lovers of vintage computers. Glad to be hear.

I recently started Sergey's Xi8088 project. The backplane, CPU card, and xt-cf card are soldered. I bought a Trident TVGA card.

I loaded the main BIOS with bios128k-2.0.bin. For the xt-cf BIOS, I tried the ide_xt.bin from the bios-0.9.0 folder, the ide_xt.bin from Sergey's website (xtide folder), as well as ide_xt.bin from Universal BIOS. Unfortunately, I'm stuck on the following screen -

Press F1 to run NVRAM setup...

Main Processor: Intel 8088 '81 or later, or OKI-designed 80C88
Mathematics Co-processor: Absent
RTC (Real Time Clock) time: FF18-01-03 14:19:57
Display Adapter Type: EGA/VGA (Video BIOS Present)
PS/2 Aux Device (Mouse): Absent
Serial Ports: COM1: none; COM2: none; COM3: none; COM4: none
Parallel Ports: LPT1: none; LPT2: none; LPT3: none
Floppy disk drives: Drive 0: 1.44 MB, 3.5"; Drive 1: none
Total Conventional RAM: 640 KiB
Available Conventional RAM: 640 KiB
Found BIOS extension ROM at CA000, initializing...
Booting OS...

-=XTIDE Universal BIOS (XT)=- @ CA00h
v2.0.0p3+ (2015-02-20)
Released under GNU GPL v2

Master at 300h: CF_128MB
Salve at 300h: not found
Booting C>>C
_

Does anybody have experience with this issue or any advice?

The DIP switches are set as follows -

On the CPU card - SW2 00000000; SW3 1000
On the xt-cf-lite card - SW1 1110; SW2 10110100

The CF card is loaded with the FreeDOS that comes with Rufus 2.18. As of right now, I don't have any other storage devices or floppies installed, just the single CF card.

Reply 535 of 613, by BloodyCactus

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you dont need bios in xt-cf-lite card, the xt ide bios is inside the xi8088 bios.

--/\-[ Stu : Bloody Cactus :: [ https://bloodycactus.com :: http://kråketær.com ]-/\--

Reply 536 of 613, by sandraos

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Thanks Cactus. I switched to bios128k-xtide-2.0.bin and disabled the xt-cf-lite BIOS. But now I get

Found BIOS extension ROM at F0000, initializing...
Booting OS...
-=XTIDE Universal BIOS (XT)=- @ F000h
Master at 300h: not found
Salve at 300h: not found

followed by Tomi Tilli's selection box [Floppy or ROM BASIC].

Reply 537 of 613, by keenerb

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sandraos wrote:
Thanks Cactus. I switched to bios128k-xtide-2.0.bin and disabled the xt-cf-lite BIOS. But now I get […]
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Thanks Cactus. I switched to bios128k-xtide-2.0.bin and disabled the xt-cf-lite BIOS. But now I get

Found BIOS extension ROM at F0000, initializing...
Booting OS...
-=XTIDE Universal BIOS (XT)=- @ F000h
Master at 300h: not found
Salve at 300h: not found

followed by Tomi Tilli's selection box [Floppy or ROM BASIC].

I seem to recall the xtide version included in Sergey's pre-built bios is ancient and doesn't work very well.

Reply 538 of 613, by sandraos

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keenerb wrote:
sandraos wrote:
Thanks Cactus. I switched to bios128k-xtide-2.0.bin and disabled the xt-cf-lite BIOS. But now I get […]
Show full quote

Thanks Cactus. I switched to bios128k-xtide-2.0.bin and disabled the xt-cf-lite BIOS. But now I get

Found BIOS extension ROM at F0000, initializing...
Booting OS...
-=XTIDE Universal BIOS (XT)=- @ F000h
Master at 300h: not found
Salve at 300h: not found

followed by Tomi Tilli's selection box [Floppy or ROM BASIC].

I seem to recall the xtide version included in Sergey's pre-built bios is ancient and doesn't work very well.

SOLVED: The BIOSes were just fine (BIOS 0.9.0 and ide_xt.bin R580 on xt-cf card). I formatted the CF with FAT16 and added system files using Rufus. Somehow that did not do the trick. But when I ghosted a disk img with DOS 6.22 using HDD Raw Copy Tool 1.1, it worked like a charm. I'm in DOS. First thing I did was run King's Quest I (nostalgic reasons =)), and it's working!

Reply 539 of 613, by coolio

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Hi. I just built my Xi 8088 CPU board and the micro ATX backplane. Before I moved forward with the other boards, I just wanted to get a boot test. And, my build doesn't work. The post code remains at "FF", but the decimal point in the post display does switch to the next one upon reset.

I've taken a logic probe to the CPU board and determined the following:

  • The power LED on the CPU board is ON
  • I hear a single click from the speak when the board turns on, but then no sound. My multimeter read a 2.7V value across the speaker at that point.
  • I've verified continuity for all address lines and data lines (CPU to memory controller, memory controller to RAM./ROM)
  • I've verified ICs getting 5V power a appropriate pins
  • The clock signal is present at the 80C88 CPU
  • The reset line at the CPU goes HI for about 1 second after pressing the reset button
  • After reset, the address lines at both the CPU, the RAM, and Flash ROM have a single pule then they go steady HI or LO

My configuration is:

  • I've tried both the v0.9 bios128k-2.0.bin and bios128k-xtide-2.0.bin
  • SW2.1 is OFF, and SW2.2-SW2.7 is ON
  • SW3.1 is ON, the rest OFF
  • Turbo mode is OFF

I'm looking for advice on my next steps in trouble shooting. I could start swapping out each IC, but that is going to get expensive to order all ICs just to determine if one is bad. I'm wondering what is the best way to isolate my problem. Any advice would be appreciated!

EDIT 1 - OK, I did some more digging and I noticed something odd, but I don't really know if it is odd (again, looking for advice). Since it seems the CPU is halted somehow, I started checking the inputs that might create that stated. I did discover that the 80c88 INTR line (pin 18) is at a constant HI state. I traced this back to the 82c59 PICs, with U5 emitting a constant HI on pin 17 (which goes to pin 18 on the 80c88). Looking at the various IRx inputs on the PICs, I noticed that the IRx inputs that are sourced from the ISA bus are all at a constant HI. I verified this with the relevant pins on a separate bus connector. It's also important to note that all internally sourced interrupts (e.g., the keyboard, etc) are at a constant LO for the relevant IRx pin. Thinking these was something wrong with the back plane, I took the Xi 8088 card out and tested the backplane with nothing in it, and the IRx lines were allLO. So this tells me it is happening on the card. As far as I can tell, there is no continuity between the ISA sourced IRx lines and Vcc. My question is whether what I am describing is a normal state? If not, what might it indicate? Bad PICs?

Michael