Riser cards as backplanes for single board computers

Posted on 2023-01-11, 11:45

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I have a hankering for building an ultra tiny 386 with one of those everything-on-a-16bit-isa-card sbc's (PC/104 is nice, but ISA is really convenient). Most come with video , but some don't, and I'd want to add audio too - that means a total of 2-3 ISA slots. That's just the right amount that you …

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Re: Cache not working on 386 mobo

Posted on 2023-01-11, 11:39

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Does cachechk report anything suspicious?

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Re: BIOS programming

Posted on 2023-01-10, 18:52

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I've just used my TL866 to flash a SST29EE010 bios this week. I use the Linux software, minipro, but the Windows application should work fine Make sure that if you buy a TL866 that it comes with the PLCC32 adapter (most bundles include at least that along with several more). Other than that, it's a …

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Re: DigiPOS adventures!

Posted on 2023-01-10, 15:47

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by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Think about ROM access speeds (=>100ns), across the ISA bus (~8MHz, 8/16bit), compared to main memory (<100ns, 16/32bit, whatever transfer speed your memory is at). I've done quite a bit of testing, including the benchmarks here for my FIC 386-SC: https://www.target-earth.net/wiki/doku.php?id=blog: …

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Re: DigiPOS adventures!

Posted on 2023-01-10, 09:46

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

PicoPSU is fitted and working. I re-used the original AT power switch wired to the PS_ON/+5VSB headers on the ATX breakout board I fitted the PicoPSU to (easier than cutting up an ATX power cable/crimping a load of wires). It's gotten rid of that nasty little 40mm PSU fan, quietened the overall …

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Re: DigiPOS adventures!

Posted on 2023-01-10, 08:16

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It's all about ISA clock (I can damn near run it at 14MHz stably on that system) and ensuring that you copy the XT-IDE rom to ram - if you're using an IDE rom replacement of course (otherwise any bios based disk access has to go over the ISA bus to access the routines in the ROM chip)! No such …

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Re: VGA Capture Thread

Posted on 2023-01-09, 23:49

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by megatron-uk

in Marvin \ Video

in Marvin \ Video

I have been using my Magewell HDMI Pro Capture for a while now and it has worked well with everything and every system thrown at it (via OSSC), but I just discovered recently that it really doesn't like the '70Hz' modes of a Matrox Millennium II. Those are modes like when running Speedsys, Doom, …

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Re: DigiPOS adventures!

Posted on 2023-01-09, 20:39

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

That does seem a tad slow. I get 1800 kB/s on my 486 with VLB I/O card. Tell me about it; on my FIC-386SC (with 486 DLC-40) I can hit 3Mbytes/sec with the same type of card (Sandisk 16GB Ultra), CF reader and a bog standard ISA multi-io card (that's with the XT-IDE rom shadowed). On a 286 with a …

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Re: Opinions on floppy drive without cast aluminum frame?

Posted on 2023-01-09, 13:36

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by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The big plus of later floppy drives is that they almost exclusively went to direct drive motors == no more belts to replace!

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Re: DigiPOS adventures!

Posted on 2023-01-07, 23:17

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Completed a full suite of benchmarks with this thing: digipos_bench.jpg Looking at Phils VGA card benchmark spreadsheet, the scores are about par for the course for the WInchip C6 200; around the same level of performance as a non-MMX Pentium 133-166. So performance-wise these are not a great chip. …

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Re: Debugging an old PC that won't boot from an SD2IDE (with XTIDE)

Posted on 2023-01-07, 17:49

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by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

How many CF cards have you tried? I've been using XT-IDE rom across several machines (have it on a 286, a 486 and a P166 on two 3c509s and an rtl8139) for many years and there are times when it just wouldn't work with particular CF brands/models. I tend to stick with SanDisk Ultra and Extreme models …

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Re: Sunlogix 80386-33/40 (Micro Express Computer) - Config Questions now

Posted on 2023-01-07, 17:18

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by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Cirrus Logic and Tseng Labs cards seem to trade blows. ET4000 cards tends to be more expensive because the have a reputation as 'the fastest' but in reality that was early on, later cards caught up and are often cheaper. Dos performance doesn't take any advantage of advanced card/chipset features, …

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Re: DigiPOS adventures!

Posted on 2023-01-07, 16:18

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I think it is the keyboard ground line, yes.

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Re: DigiPOS adventures!

Posted on 2023-01-07, 10:55

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I wouldn't have thought a fuse could do this, but..... IMG20230107104603-.jpg The Dell PS/2 keyboard now powers up! Even better... https://youtube.com/shorts/9GHAhATI0YU No more dropped keys when typing fast! And key repeat is working as you would expect it (hold a key and it repeats indefinitely, …

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Re: DigiPOS adventures!

Posted on 2023-01-07, 10:21

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Looking at what could be wrong with the keyboard interface and started taking a closer look around the port. There's what appears to be a typical keyboard / PS2 fuse near the AT keyboard port (FS1), which seems to be directly connected to the solder point I have highlighted (at least when measured …

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Re: Help with Rufus Boot USBs?

Posted on 2023-01-07, 09:56

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Am I right in thinking the built-in Freedos option works... but that when you use a *floppy disk image* from bootdisk.com, it doesn't? I think that may be the key - I don't think you can write a 3.5" floppy disk image to the start of a USB flash drive and it work like that... unless I'm mistaken? …

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Re: Sunlogix 80386-33/40 (Micro Express Computer) - Config Questions now

Posted on 2023-01-07, 09:39

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

System BIOS shadow & Video BIOS shadow = turn on for fastest access Memory read/write wait stats = as low as possible (you may have to test and retest until you find the system to still be stable) ISA clock = *most* later cards will tolerate 10MHz fine, but again you may have to experiment - you'll …

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Re: How do I add Joystick capability for old laptop?

Posted on 2023-01-07, 09:21

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by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

In DOS? No. DOS has no understanding of USB at *all* (beyond USB keyboard if your BIOS has 'emulate legacy keyboard support' or some similar setting). That adapter looks like it will let you use gameport (15 pin) joysticks on systems without a gameport, but you will need a driver for it; I'm 99.99% …

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Re: DigiPOS adventures!

Posted on 2023-01-06, 23:11

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by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

It's not the BIOS / settings that are doing this, as I tried the various M1521 images available here: https://theretroweb.com/bios/?biosManufacturerId=75&chipsetId=178 A couple of them work and the system boots up (not with the onboard Cirrus vga, as none of those bios files have an onboard CL7528), …

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Re: DigiPOS adventures!

Posted on 2023-01-06, 22:14

by

by megatron-uk

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Video of the Digipos in action showing keyboard input being dropped as the typing gets quicker: https://youtube.com/shorts/pXgD0HT0VLU Stick to hunt-and-peck input and it would be (more or less) usable, apart from the lack of key repeat function. Not sure there's much more I can do to resolve this …

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