Re: Xi 8088 by Segey Kiselev

Posted on 2017-11-30, 15:58

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

but we all have different backplane, different psu, video card etc. but we all see similar problems. I dunno what the answer is. It could be we're all suffering from different issues. For example, if I recall correctly, my bus terminator board improved my stability, but did not improve keenerb's …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-11-30, 06:22

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I've got one arriving Friday. I think I have everything I need already to put it together. I am optimistic the FE2010A chipset will address the stability issue in the xi8088... Built mine over the weekend. My PC is every bit as unstable. ;( This makes me think there's something else going on. We've …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-11-24, 07:56

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In other homebuilt 8088 news, Sergey now has his "Micro 8088" boards available for sale. There's a thread describing them on the retrobrew forum.

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-11-24, 07:54

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Scott, How does the 2MB EMS board function in the 8088 system? I'm ordering parts to assemble mine soon. Just wondering if you need a memory driver to allow the system utilize it? There is a lo-tech EMS driver that you install into your config.sys. It was a piece of cake for me to get working. BTW, …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-10-26, 00:15

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Actually, doesn't CheckIt DEFINITELY have a bug? I know it logs results to memory, and running a FULL memory test with many iterations results in an error due to running out of RAM. Or was that another piece of software I was using. I need to double-check. That is check-it you're remembering. I'm …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-10-23, 15:39

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by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

except PCB cost$ is by dimension. adding another 1/4" by whatever height * number of boards would be a huge expense. Yes, it would have cost more, but I'm not buying that it would have been a huge expense. While it may have been rounded up and cost disproportionately more than just the quarter inch …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-10-23, 04:46

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I wonder if you could make an L shaped standoff from off the shelf material, then cut and drill it to the right length for your card. Printing a bracket seems excessive. I have some of these 4-40 L-brackets from Sparkfun: https://www.sparkfun.com/products/10228. My plan (unless I come up with …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-10-22, 23:43

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Interesting it ran so long then halted. Wonder if there is a weak solder joint that's failing after it's warmed up? Even more interesting that it happened again today, on passes 123 and 124. I'm thinking there is a software bug involved, either in the EMS driver or in checkit itself. Hardware …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-10-22, 15:32

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by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ran an all-night checkit on the EMS board. It failed at passes 123 and 124, and then checkit halted the memory test due to too many errors.Will continue to let it run during the day today to collect more data. Scott

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-10-22, 03:46

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by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I built the 2MB EMS board today. It's working fine in my Xi 8088... at least so far. One thing that's annoying about these Lo-Tech boards is that they seem to be a nonstandard size -- the standard keystone bracket won't fix it, so I have no ISA bracket attached to it. Seems like it would have been …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-10-21, 20:05

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Awesome, Can this be used to extend the memory of the XI8088 using it as ems or xms? The 1MB board is strictly for the 0-1MB range, so it's completely redundant with the Xi 8088's onboard SRAM. This is indended for systems like the IBM 5150 that might have very little onboard RAM, as little as 16 …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-10-21, 15:11

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

gdjacobs wrote: Is Lo-Tech still making boards? They had a Tandy audio expansion board which would be fantastic for early PCs. Lo-tech licensed the design to texelec.com and you can buy them there now. Both bare PCBs and completed boards. I don't see the Tandy board listed on the site though. Scott …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-10-21, 04:12

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I built the Lo-Tech 1MB board today. I haven't done a SMD project in a while, and I sure was rusty... Hilights included soldering the SRAM crooked and having to redo it, soldering 74HCT139 in place of 74HCT138 and having to redo it, and somehow bending a pin on the 74HCT30 leading to a cold solder …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-10-19, 18:28

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Also be sure to check the seating of all cards in the backplane. I'm not entirely sure why, but sometimes I'll have POST errors until I fidget with the Xi 8088 card a few times and then it'll work fine for several days or even weeks. I used some eBay card connectors on my backplane -- maybe they …

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Re: HardMPU, anyone?

Posted on 2017-10-19, 18:22

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by smbaker

in Marvin \ Sound

in Marvin \ Sound

It was my own addition, I decided to use the extra pins on the connector for the possibility of future expansion - For example, one could jumper the second UART on the microcontroller to run an external display if they don't have a real MT32. Cool! I'm definitely a fan of not letting unused …

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Re: HardMPU, anyone?

Posted on 2017-10-19, 16:04

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by smbaker

in Marvin \ Sound

in Marvin \ Sound

When I use my multimeter to check which pins of the DE-9 male connector plugged into the HardMPU connect to which pins of the male 5-pin DIN connector that I plug into my Roland MT-32, this is what I end up with: For what it's worth, I just checked my cable and this is identical to mine. I built my …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-10-17, 23:39

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I ordered myself the 1MB conventional and 2MB EMS PCBs from texelec this week, as well as all the parts to complete them from digikey. I don't really have a need for the 1MB board at this time, but it seems to be a useful thing to grab while they're available, and will provide a useful datapoint on …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-09-27, 05:33

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by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I already picked up a few FE2010A ics... LOL, 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) …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-09-24, 06:53

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by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

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 ( …

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Re: Xi 8088 by Segey Kiselev

Posted on 2017-09-21, 03:56

by

by smbaker

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

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 …

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