Search found 165 matches

by ecksemmess
Sat 04 Mar, 2017 7:39 pm
Forum: Development
Topic: ST-412/ST-506/ESDI hard drive emulation?
Replies: 51
Views: 15310

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: 15310

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: 2068

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: 4509

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: 10172

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: 10172

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: 2697

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: 2984

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: 2697

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: 2697

[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: 20824

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: 20824

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: 1562

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: 5763

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: 5763

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: 5763

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: 14097

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: 14097

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: 14097

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: 14097

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: 4741

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: 3428

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: 14097

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: 5763

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 ...
by ecksemmess
Sun 27 Sep, 2015 7:07 am
Forum: General
Topic: Dynarec execution rate plummeting drastically at DOS prompt
Replies: 16
Views: 5763

Re: Dynarec execution rate plummeting drastically at DOS pro

Yeah, I get it. Check out this post, though: http://pcem-emulator.co.uk/phpBB3/viewtopic.php?f=3&t=85&start=90#p1077 That's Tom's most recent dynarec performance summary. Note, right off the bat: DOS prompt - 96% faster (55% / 108%) 108% at the DOS prompt! And I believe that Tom was running the fast...
by ecksemmess
Wed 23 Sep, 2015 5:24 am
Forum: General
Topic: Dynarec execution rate plummeting drastically at DOS prompt
Replies: 16
Views: 5763

Re: Dynarec execution rate plummeting drastically at DOS pro

ecksemess, could you post your CONFIG.SYS and AUTOEXEC.BAT files here? There may be something there causing slowdown, most of my benchmarking was done on a clean boot. In general though, idling (on pretty much any operating system) hits all the weak points in the current recompiler and hence doesn'...
by ecksemmess
Tue 22 Sep, 2015 3:02 am
Forum: General
Topic: Dynarec execution rate plummeting drastically at DOS prompt
Replies: 16
Views: 5763

Dynarec execution rate plummeting drastically at DOS prompt

In general, I've been getting great performance out of the dynarec, but I've noticed that the execution percentage plummets strangely while idling at the DOS prompt, in ways that suggest that something other than the usual issue of an idle loop hitting one of the dynarec's weak points may be the cul...
by ecksemmess
Wed 16 Sep, 2015 9:50 am
Forum: Development
Topic: Patch: Fix for error in re-ordering of ROM set enum
Replies: 4
Views: 2316

Patch: Fix for error in re-ordering of ROM set enum

An oversight in the re-ordering of the ROM set enum in r346 has caused problems for the Phoenix 386 and the DTK 386, which have now lost their 386 classification. Actually, the problem was worse than that, as there were several misclassifications even before the re-ordering in r346 (IBM PS/1 Model 2...
by ecksemmess
Mon 14 Sep, 2015 7:35 am
Forum: General
Topic: Cache size?
Replies: 7
Views: 3654

Re: Cache size?

Granted that the cache simulation feature obviously has its shortcomings, I've found it incredibly useful as an auxiliary speed- and performance-tweaking feature when the main settings on their own aren't quite allowing me to get the emulated system to behave the way I want it to. I've spoken to sev...
by ecksemmess
Sat 12 Sep, 2015 8:02 am
Forum: General
Topic: r328: OS/2 Warp 3 format error; CD access crashes PCem
Replies: 70
Views: 35742

Re: r328: OS/2 Warp 3 format error; CD access crashes PCem

Return to Zork required 19,519 *KB* of RAM for its sound drivers?! No wonder I had so much trouble getting that game running! ;) In all seriousness, yes, 580-some KB was an incredibly daunting requirement back in the day. I remember. Oh god, do I remember. I was there for "the hell that was MS-DOS+I...