Re: I need help with SCSI setup - SS7 + Adaptec 39160.

Posted on 2019-08-27, 02:54

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Its probably normal if someone is questioning some old paradigma, that such reaction are normal. Few notes: 1) Because you now invented some imaginary problems which i have, i dont really have any, my setup is working, as much as i tested it. BTW i never had hooked more that 1 device. 2) Nobody …

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Re: Worth it to try to push ISA bus past 12MHz?

Posted on 2019-08-27, 02:51

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Spent the better part of the day sunday pulling the system all apart, socketing the oscillator, and reassembling. Turned out to be mostly a waste of time but I did discover something odd. I stuck a scope on the ISA clock pin B20 and put it in freq counter mode. The stock oscillator is 48MHz. The CPU …

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Re: Voodoo 2 SLI and 1024x768

Posted on 2019-08-27, 01:04

by

by maxtherabbit

in Marvin \ Video

in Marvin \ Video

Dude, you need a dictionary. It's RENDERING THE IMAGE. IN MEMORY. The exact same triangles, the exact same textures, the exact same image. Are you TRYING to troll here? This is too wrong. Why do you think framerate increases with a v2 sli? Because the rendering work is spread across two cards. Yes …

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Re: WfW 3.11 - how this guy did that?

Posted on 2019-08-24, 16:50

by

by maxtherabbit

in Marvin \ Software

in Marvin \ Software

Its showing out of sync because many/most ISA and VLB cards default to using interlaced scan modes for 1024x768 to achieve compatibility with old VGA displays. Look for a manufacturer specific utility for your video card to select a 60Hz progressive timing mode for 1024x768

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Re: CD rom in 386 problem...

Posted on 2019-08-24, 16:40

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

BIOSes in pre pentium systems do not detect CDROMs and, here's the important part - it doesn't matter The DOS CDROM driver (I recommend VIDE-CDD.SYS) will scan master and slave on both channels and pick up the drive. The BIOS 100% doesn't matter

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Re: Why does EMS suck on my 286?

Posted on 2019-08-23, 17:23

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If you want real performance, a CF-IDE setup will beat a SCSI HDD any day of the week. that's demonstrably false, at least on this system I did an entire thread over at VCFED documenting the performance of various disk systems. SCSI crushed CF-IDE, most likely due to the bus mastering DMA. http:// …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-23, 17:21

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I believe I have come up with a theory that fits the facts - and it is deceptively simple What if the Adaptec card is simply not asserting SBHE# when is does DMA transfers to the C or D segments? We already know that it assumes all DMA accesses outside of the A and B segment to be 16 bits wide, but …

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Re: Anyone here using an MFM drive in an XT-class system?

Posted on 2019-08-23, 16:40

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I no longer use MFM. Now it's a combination of SCSI and SCSIDE + CF card. My old MFM setup was pretty cool though. At one point I had dual ST-251s, which normally format to about 40mb each. However, I stuck them on a WD1002A-27X RLL controller, and I think each of them became 52mb. I can't say I …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-23, 15:24

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

The point is that the real mode software you want to run would run on a 286 AT machine flawlessly with the EMS attached. The drive is just a mere disk storage - INT13h ;) The SCSI drives were exotic back then. Hence the bugs. MFM/IDE was de facto the standard for the PC hard drives natively …

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Re: Anyone here using an MFM drive in an XT-class system?

Posted on 2019-08-23, 15:12

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

mTCP is the gold standard, if you have a slot for a NIC anything less is really just inferior

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Re: Why does EMS suck on my 286?

Posted on 2019-08-23, 14:20

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

maxtherabbit, could you clone your hard drive and use an IDE drive instead? I don't know what the point of such an exercise would be. IDE isn't going to perform bus master DMA transfers and will almost certainly work just fine. I know I can write arbitrary data to the page frame manually in DEBUG …

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Re: Anyone here using an MFM drive in an XT-class system?

Posted on 2019-08-23, 03:35

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

my IBM 5150 is equipped with two working ST-225s in the left full height bay, and dual floppies in the right bay I use a WD8003 NIC and mTCP for file transfer, it's honestly easier than moving a CF card around and the FTP programs have no problem saturating the disk I/O

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Re: Legit Harris 25MHz?

Posted on 2019-08-23, 03:01

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So if no one is manufacturing Harris branded 286s in 2019, that would out this pictured CPU as a remarking or outright fake, right?

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Re: Why does EMS suck on my 286?

Posted on 2019-08-23, 01:54

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Here's an excerpt from the manual of "The Last Byte" memory manager. I can't help but think this is somehow related, even though it still doesn't explain why both 16-bit EMS boards shit the bed with word writes. Address lines A15 and A16 are not latched in hardware design of the AT bus. As a …

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Re: Legit Harris 25MHz?

Posted on 2019-08-22, 19:43

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by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

derSammler wrote: Renesas? We are talking about Harris. Renesas owns Intersil, which was spun off from Harris' semiconductor division in 1999

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Legit Harris 25MHz?

Posted on 2019-08-22, 15:55

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

looks real, has anyone purchased one of these?

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Re: Why does EMS suck on my 286?

Posted on 2019-08-22, 15:51

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

DMA writes. I've been using the DEBUG utility to load a sector from disk into memory as a test. It would really be more clear if you read the thread

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Re: Why does EMS suck on my 286?

Posted on 2019-08-22, 14:45

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

AST Rampage Plus 286 that has 8 30-pin SIMM slots on it. And what do you know - when I set up EMS with the included driver I once again can only perform 8-bit writes to the page frame. I don't know for sure, but at least my AST Rampage came with an outdated device driver (more precisely, it came …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-22, 14:43

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Or perhaps EMS only allows 8-bit access by design? I don't think it does. I had a 386SX-16 with NEAT chipset, that had EMS onboard, and that worked fine with 16-bit access afaik. Would make sense anyway, since EMS is a very lowlevel interface... You just get a base segment, and you address that. …

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Re: Why does EMS suck on my 286?

Posted on 2019-08-22, 03:59

by

by maxtherabbit

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

So I did revisit EMS on this system - got a deal on an AST Rampage Plus 286 that has 8 30-pin SIMM slots on it. And what do you know - when I set up EMS with the included driver I once again can only perform 8-bit writes to the page frame. There's got to be something about either my chipset or …

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