Re: Xi 8088 by Segey Kiselev

Posted on 2016-07-21, 12:31

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'm running mine with 32mhz crystal as well now, my only issue is the beeping. I haven't figured out how important that adjustable capacitor is, maybe you should look into that. I am at the point where I"m considering ordering a new board + sockets and transferring my logic over, this beeping issue …

---

Re: Xi 8088 by Segey Kiselev

Posted on 2016-07-17, 15:35

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I picked up a programmer that has logic testing and all the 74 series chips passed multiple runs. Doesn't mean there isn't an issue but they test ok. I had already replaced those particular chips anyway. What video card are you using on yours? Mine is fine with an EGA/CGA/MDA, but all three VGA …

---

Re: Xi 8088 by Segey Kiselev

Posted on 2016-07-17, 02:11

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I can duplicate this now 100% under various circumstances. Still no idea what's up. The beeping occurs during the video card bios initialization and stops at port 80 post code 12, which is when RTC initialization happens. I do notice that Sergey's port map has various i/o ranges aliased to the pc …

---

Re: Xi 8088 by Segey Kiselev

Posted on 2016-07-15, 01:59

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

OK so I have EVERYTHING together, including my ISA backplane (and upgraded to 32mhz oscillator for my 10mhz V20). The beeping is recurring. It's NOT just the xt-ide board; two 8-bit VGA cards cause similar behaviour during post, but it goes away as soon as the floppy boot starts. The POST code where …

---

Re: Windows 3.x security

Posted on 2016-07-13, 14:19

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

There may be a PGP version that runs in 16-bit pure dos, but that won't do full disk encryption.

---

Re: Xi 8088 by Segey Kiselev

Posted on 2016-07-09, 23:06

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

WHELP... I guess I'll just have to hope it's right...

---

Re: Xi 8088 by Segey Kiselev

Posted on 2016-07-09, 22:20

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That's interesting. I have no idea how I'd calibrate that. I don't have any idea what the current capacitance is on that, in fact.

---

Re: Xi 8088 by Segey Kiselev

Posted on 2016-07-09, 02:14

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Well good news for me. This bizarre beeping seems to be directly related to my XT-IDE compact flash board from LoTech; when I boot from it, the beeping intermittently occurs. when booting solely from floppy disk (CF adapter installed but not accessing hard drive) everything seems to be fine; I ran …

---

Re: Xi 8088 by Segey Kiselev

Posted on 2016-07-07, 21:16

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Here's what's going on with my xi8088. https://www.youtube.com/watch?v=JQBsQMb7p6Y&feature=youtu.be The machine seems completely usable other than the occasional loud and extended beeping. I've no idea what's up. Also, what is C54 for? It's the adjustable trimmer capacitor.

---

Re: Xi 8088 by Segey Kiselev

Posted on 2016-07-01, 00:05

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Well there appears to be some problem or other with my xi8088 still. I purchased three NEC v20 cpus; one was in the board when I shorted +5v to ground and does not function at all. Witht he second installed, my board boots but ultimately starts playing a 400hz tone and will lock up. The third CPU …

---

Re: Xi 8088 by Segey Kiselev

Posted on 2016-06-30, 17:03

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I'm digging through the BIOS source and it seems like there's maybe a keyboard combination to toggle turbo status? atkbd.inc, line 316. Or maybe the actual turbo button is handled here, I don't know enough to be able to tell. If it's NOT handled here, I bet it would be easy enough to add a key …

---

Re: Xi 8088 by Segey Malinov

Posted on 2016-06-30, 15:04

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

were you on turbo? Id expect it to get hot if your on turbo since it runs in lock step with the cpu. I dont remember them getting super hot at 4mhz... but its been a long time so maybe they did. I actually bought an 8087-1, which is supposed to be a 10mhz part and I'm only running it at 8mhz in …

---

Re: Xi 8088 by Segey Malinov

Posted on 2016-06-30, 13:41

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Damn the 8087 runs HOT. I pulled it out, I bet it's pulling more power than the entire rest of the system. Not worth it just to speed up Lotus 1-2-3... Tested out a bunch of games and apps last night, doesn't seem much slower than my tandy 1000TL. DOSShell has some weird blinking thing going on …

---

Re: Xi 8088 by Segey Malinov

Posted on 2016-06-30, 01:04

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I tested out all the logic ICs, they were all fine. I jumped the burnt trace and replaced all the non-logic ICs I had spares of (cpu, keyboardcontroller, etc.) and it's alive! http://i.imgur.com/YPY9hhSl.jpg One strange thing: After a little while the system starts broadcasting a beep for some …

---

Re: Xi 8088 by Segey Malinov

Posted on 2016-06-29, 21:41

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Well I flashed the ROM but have no boot, no beep. Must have killed it, or one of the components I ordered is bad... Actually, since that trace from the speaker was burnt out perhaps I should jumper that across the back of the board and see what happens. According to the board diagram pdf, pin 4 …

---

Re: Xi 8088 by Segey Malinov

Posted on 2016-06-29, 18:54

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I had a few 4-slot ISA backplanes laying around. Will be enough for 8088 board, floppy adapter, IDE adapter, and video card. If I didn't kill the 8088 I'll pick up the parts for the backplane as well,

---

Re: Change 286 CPU on Mainboard

Posted on 2016-06-29, 18:01

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It's interesting that it has an empty oscillator socket. Does it have something to do with the 80287 socket?

---

Re: Xi 8088 by Segey Malinov

Posted on 2016-06-29, 16:44

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

programmer is out for delivery today. What backplane is everyone using? Have you built Sergey's or using a pre-made one?

---

Re: What to do with rusted cases?

Posted on 2016-06-28, 16:45

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I used vinegar and a ball of aluminum foil to clean a pretty badly rusted Tandy 1000RL chassis. Seemed to work fairly well, needed a little wipedown/cleanup afterwards but looks 10x better.

---

Re: Xi 8088 by Segey Malinov

Posted on 2016-06-28, 14:57

by

by keenerb

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The trace from the GND terminal on speaker to the capacitor directly alongside U31 is open, so definitely burnt that out. I could jumper that along the back if needed though, I think. The capacitor itself measures same with my shitty little meter as all the other similar capacitors of it's type, and …

---