Search found 171 matches

by ecksemmess
Thu 09 Mar, 2017 11:13 am
Forum: General
Topic: PCem 12 and slowmotion issue
Replies: 49
Views: 21827

Re: PCem 12 and slowmotion issue

Interesting. Do we have any idea why the discrepancy there is so big? The fact that PCem is getting performance comparable to your 300 MHz system at a little over half its clock speed seems pretty out of whack. That's too much of a difference to be due to the obvious culprits like the "infinite" cac...
by ecksemmess
Mon 06 Mar, 2017 11:43 pm
Forum: Development
Topic: [Request] Screenshot
Replies: 2
Views: 1463

Re: [Request] Screenshot

This could be cool, but would definitely have to be implemented as a disable-able option, so as not to interfere with PrntScrn key functionality within the emulated system itself. Although I suppose it might be possible to have PCem run a handler that captures the screenshot and then just passes the...
by ecksemmess
Mon 06 Mar, 2017 11:20 pm
Forum: Development
Topic: ST-412/ST-506/ESDI hard drive emulation?
Replies: 51
Views: 17790

Re: ST-412/ST-506/ESDI hard drive emulation?

Seems there were two versions or "generations" of the card, both by WD. The second version was also used in the XT 286. Lots of good info here: http://minuszerodegrees.net/5170/cards/5170_cards.htm#fddda_1 . Full documentation from IBM for the first-gen version here: http://minuszerodegrees.net/oa/O...
by ecksemmess
Mon 06 Mar, 2017 11:08 pm
Forum: Development
Topic: ST-412/ST-506/ESDI hard drive emulation?
Replies: 51
Views: 17790

Re: ST-412/ST-506/ESDI hard drive emulation?

Was just looking into that myself--yep, it was developed by Western Digital and was indeed later used as the foundation for IDE. Seems like an excellent choice.
by ecksemmess
Mon 06 Mar, 2017 9:48 pm
Forum: Development
Topic: ST-412/ST-506/ESDI hard drive emulation?
Replies: 51
Views: 17790

Re: ST-412/ST-506/ESDI hard drive emulation?

SCSI support would be nice to have, but wouldn't really serve as a substitute for proper MFM emulation. There's a fair amount of early '80s productivity software that, for whatever reason, doesn't play well with SCSI.
by ecksemmess
Sun 05 Mar, 2017 10:11 am
Forum: Development
Topic: ST-412/ST-506/ESDI hard drive emulation?
Replies: 51
Views: 17790

Re: ST-412/ST-506/ESDI hard drive emulation?

Good point. Maximizing the flexibility and range of supported drives is the obvious thing to do at the outset. Presumably that means looking at controllers from the last major wave of MFM cards (1986-87 or so, IIRC), yes? Some quick research suggests that there is fairly broad agreement that the Wes...
by ecksemmess
Sat 04 Mar, 2017 7:39 pm
Forum: Development
Topic: ST-412/ST-506/ESDI hard drive emulation?
Replies: 51
Views: 17790

Re: ST-412/ST-506/ESDI hard drive emulation?

Interesting--I hadn't realized that ST-412 and ST-506 were both totally reducible to just "generic MFM" at the controller level. One controller emulated at a time seems like a perfectly reasonable limitation, of course (assuming you mean "one controller running at any given time", and not "one contr...
by ecksemmess
Sat 04 Mar, 2017 8:49 am
Forum: Development
Topic: ST-412/ST-506/ESDI hard drive emulation?
Replies: 51
Views: 17790

ST-412/ST-506/ESDI hard drive emulation?

I must say that I've been thrilled at how far PCem has come in just a couple of years. For the early-era enthusiasts like me, it's especially gratifying to have a near-perfect emulation solution for emulating almost all of the major basic PC hardware elements from throughout the 1980s. The single mo...
by ecksemmess
Sat 25 Feb, 2017 2:28 am
Forum: Development
Topic: [Patch] IBM PS/2 Model 30-286
Replies: 3
Views: 2383

Re: [Patch] IBM PS/2 Model 30-286

Very cool! Glad to see this, thanks dns2kv2. I would just point out that the PS/2 line came before the PS/1 line, and specifically the PS/2 Model 30-286 is a good couple of years older than the similar PS/1 Model 2011--indeed, the former was the basis for development of the latter. Therefore, it wou...
by ecksemmess
Mon 16 Jan, 2017 10:07 am
Forum: Development
Topic: [Patch] OPL3 correction in Sound Blaster
Replies: 11
Views: 5139

Re: [Patch] OPL3 correction in Sound Blaster

Agreed with leilei. That "Nuked" OPL3 emulation update really steps up the accuracy. It would be a delight to have it in PCem.
by ecksemmess
Wed 11 Jan, 2017 6:34 pm
Forum: General
Topic: Can we make PCem much faster?
Replies: 19
Views: 11558

Re: Can we make PCem much faster?

Fair enough. Mainline or not, it's something that might be fun to mess around with way down the road, but if the goal is to keep PCem-proper focused squarely on emulation, that's perfectly understandable.
by ecksemmess
Wed 11 Jan, 2017 5:01 am
Forum: General
Topic: Can we make PCem much faster?
Replies: 19
Views: 11558

Re: Can we make PCem much faster?

Even with these improvements though, I think there is an upper limit on how much performance we can get - my rough estimation would be around 500-600 MHz on current hardware. To go beyond that would mean going down the virtualisation route; this would mean loosing the ability to control emulated CP...
by ecksemmess
Wed 04 Jan, 2017 5:58 am
Forum: Development
Topic: [PATCH] RAM size range correction
Replies: 6
Views: 3083

Re: [PATCH] RAM size range correction

Fair enough. Thanks!
by ecksemmess
Sat 24 Dec, 2016 11:03 pm
Forum: Development
Topic: [Request] SCP (Supercard Pro) Support
Replies: 8
Views: 3467

Re: [Request] SCP (Supercard Pro) Support

I'm pretty sure flyers80 was talking about Supercard Pro format support on the host side, not the guest side. It's a floppy image format that samples disks at the flux level, similar to Kryoflux. I'm not sure exactly what's involved in adding support for those formats, but it kinda seems like way mo...
by ecksemmess
Wed 21 Dec, 2016 9:58 pm
Forum: Development
Topic: [PATCH] RAM size range correction
Replies: 6
Views: 3083

Re: [PATCH] RAM size range correction

There absolutely was a 64KB configuration of the IBM PC/XT, though rare. I had one for years. There are a few sites around the web attesting to this--for example, see http://www.old-computers.com/museum/computer.asp?c=286 . I also have a few early 80s computing magazines and newsletters where people...
by ecksemmess
Wed 21 Dec, 2016 7:41 am
Forum: Development
Topic: [PATCH] RAM size range correction
Replies: 6
Views: 3083

[PATCH] RAM size range correction

I've just noticed that, with some of the early models, the allowed RAM size range doesn't cover the full gamut of what was available on each model during its lifetime. The cloned XT systems are a bit tricky, but I currently own (or have owned) several of these and can attest from experience that som...
by ecksemmess
Sat 14 Nov, 2015 12:48 pm
Forum: General
Topic: FredPJ's feature suggestions
Replies: 40
Views: 22819

Re: FredPJ's feature suggestions

Yes! I saw it once years ago and have never been able to identify it until now. What incredible luck--thank you. :)
by ecksemmess
Sat 14 Nov, 2015 9:58 am
Forum: General
Topic: FredPJ's feature suggestions
Replies: 40
Views: 22819

Re: FredPJ's feature suggestions

Startmenu, that game in your screenshot looks hauntingly familiar but I can't quite place it. What is it?

(Also, I agree that a 4:3 windowed mode, preferably with window resizing enabled, would be a fantastic addition to PCem.)
by ecksemmess
Fri 13 Nov, 2015 7:28 am
Forum: Development
Topic: PATCH: Correction in loading of Endeavor BIOS
Replies: 1
Views: 1740

PATCH: Correction in loading of Endeavor BIOS

Attached is a patch for mem.c which corrects a minor error in the loading of the Endeavor's BIOS. The current code seems to presume that the Endeavor uses the same size BIOS as the Batman's Revenge, which is wrong. Of course, in actual hardware terms they both use similar 128 KB Flash ROMs, but in f...
by ecksemmess
Fri 06 Nov, 2015 12:03 am
Forum: General
Topic: Dynarec execution rate plummeting drastically at DOS prompt
Replies: 16
Views: 6524

Re: Dynarec execution rate plummeting drastically at DOS pro

Good to know. I had been confusing the HMA with one of the memory areas just below the 1 MB boundary. Realizing now that it's just above that boundary, what you say makes sense, and probably does explain what's going on here. It's not a big deal, but it would be nice to get that code sorted that's s...
by ecksemmess
Thu 05 Nov, 2015 11:07 am
Forum: General
Topic: Dynarec execution rate plummeting drastically at DOS prompt
Replies: 16
Views: 6524

Re: Dynarec execution rate plummeting drastically at DOS pro

For me it's definitely not related to the cache setting. There's something else going on. Are you using EMM386 or similar? If so, try disabling it. I've found that EMM386 triggers another entirely unrelated bug in PCem that drastically slows down the emulated PC under certain conditions, thereby art...
by ecksemmess
Thu 05 Nov, 2015 6:17 am
Forum: General
Topic: Dynarec execution rate plummeting drastically at DOS prompt
Replies: 16
Views: 6524

Re: Dynarec execution rate plummeting drastically at DOS pro

Sorry to bump this, but I've now noticed something else of interest in relation to this. Regardless of how the emulated system is configured, when DOS is loaded "low"/"noumb", the dynarec doesn't choke at the DOS prompt at all. The execution rate never dips below 100% at all, even when emulating the...
by ecksemmess
Sun 01 Nov, 2015 7:46 pm
Forum: General
Topic: v10 released!
Replies: 39
Views: 16229

Re: v10 released!

It's been years since I actually played with one of these boards, but I could have sworn that that particular BIOS managed to detect the presence of serial mice as well. I might be thinking of a different board, though.
by ecksemmess
Sun 01 Nov, 2015 6:36 pm
Forum: General
Topic: v10 released!
Replies: 39
Views: 16229

Re: v10 released!

Sorry, I must be missing something - in what way does this make the Advanced/EV unusable? The BIOS POSTs with no errors, and DOS mouse drivers and Windows correctly detect and use the serial mouse. D'oh! There are actually two issues, one of which was entirely my fault, and I appear to have conflat...
by ecksemmess
Sun 01 Nov, 2015 8:43 am
Forum: General
Topic: v10 released!
Replies: 39
Views: 16229

Re: v10 released!

Sorry, should have been more clear--the Advanced/EV is currently unusable, because the BIOS detects no mouse at all. Battler seems to think that fixing this will be as simple as switching the mouse init on that machine over to PS/2. Been so swamped I haven't had a chance to verify that, and alas sti...
by ecksemmess
Sun 01 Nov, 2015 12:43 am
Forum: General
Topic: v10 released!
Replies: 39
Views: 16229

Re: v10 released!

Nice one, great to see that the issue with the Premiere/PCI wasn't too much of a problem and it will be good to have it back in action. Any chance of getting the mouse re-enabled on the Advanced/EV in time for 10.1 as well? I had a quick look and it did seem as straightforward as Battler indicated b...
by ecksemmess
Sat 31 Oct, 2015 5:00 am
Forum: General
Topic: Security issues in PCem [possible emulator escape]
Replies: 12
Views: 5428

Re: Security issues in PCem [possible emulator escape]

It could easily become an issue as PCem gains in popularity, which seems likely to happen. There will be games and other software titles that become widely known for running best in PCem, and it would then be trivial for someone to release infected versions of those titles to abandonware sites which...
by ecksemmess
Tue 27 Oct, 2015 8:00 am
Forum: General
Topic: original resolution output?
Replies: 7
Views: 3960

Re: original resolution output?

Yes, it's possible, but I'd imagine demand for this would be near non-existent. I can't speak for Tom, but I'd guess that you're likely the first person who has ever bothered to ask for this. That said, it's an understandable thing to want if you're one of the vanishingly few people running a modern...
by ecksemmess
Sun 25 Oct, 2015 9:24 am
Forum: General
Topic: v10 released!
Replies: 39
Views: 16229

Re: v10 released!

Fantastic work all around, Tom. Everything looks to be working properly with the v10 package now. I also noticed the duplication of the "4 IDE hard drives" in the feature list, but I see that neozeed beat me to it. :) I can also confirm that exiting the CMOS settings crashes PCem on the Intel Premie...
by ecksemmess
Mon 28 Sep, 2015 5:05 am
Forum: General
Topic: Dynarec execution rate plummeting drastically at DOS prompt
Replies: 16
Views: 6524

Re: Dynarec execution rate plummeting drastically at DOS pro

That was a clean boot of DOS 6.22, on a Winchip 240 (the fastest CPU emulated when I started the recompiler, somewhat slower than the Pentium MMXes you can emulate now), on a 3.6 GHz Ivy Bridge Core i5. If your setup differs from this at all then I'd expect the performance to drop somewhat. Thanks ...