8086 emulation

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Mills
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8086 emulation

Postby Mills » Fri 29 Sep, 2017 6:26 pm

Hi, I'm new in PCem so I might be doing something wrong.

I wanted to emulate a machine like this:
8086 8 Mhz
640 kb ram
VGA

(I really wanted to emulate PS/2 Model 30 8086 with MCGA, But it is OK with the VGA).

Some of the predefined machines show a 8086 cpu type, like Amstrad PC1512 for example.

But at msdos start I get this error:
HYMEM.SYS requires a 80x86 based machine.

Also if I run some benchmark programs, MSDOS only finds a 8088 cpu. and some games and programs that worked in a real 8086 I had, are not working with this.

I could not find any configuration that makes msdos find the 8086, allways showing 8088 and that error.

What am I doing wrong?
How different are 8088 and 8086?

Thanks a lot.
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ruben_balea
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Re: 8086 emulation

Postby ruben_balea » Sat 30 Sep, 2017 5:27 am

Hi,
Can't use HIMEM.SYS with a 8086/88 because for HIMEM.SYS 80x86 means 80286, 80386 and so on.

8086/8088 can only access 1MB or memory, to use HIMEM.SYS you need at least a 286 with enough memory, on some chipsets even with only 1 MB you'll get a small amount of extended memory,
because some memory which will remain unused because initially it's on the same address as other things is "switched" to an address above the first MB,
other chipsets won't do this and you need more than 1 MB installed to access any extended memory (XMS) with HIMEM.SYS

At least in some versions of DOS you can load HIMEM.SYS even without any XMS available but of course free XMS will be 0 bytes.

Almost any 8086 program should work perfectly on a 8088 because all IBM PC and XT models and most of their clones had 8088's from 4.77 to 12MHz.

About the emulation problems I don't know, perhaps someone can help if you tell what program(s) or game(s) you want to use.

Greetings.
Mills
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Re: 8086 emulation

Postby Mills » Sat 30 Sep, 2017 10:38 am

ruben_balea wrote:8086/8088 can only access 1MB or memory, to use HIMEM.SYS you need at least a 286 with enough memory, on some chipsets even with only 1 MB you'll get a small amount of extended memory,

Almost any 8086 program should work perfectly on a 8088 because all IBM PC and XT models and most of their clones had 8088's from 4.77 to 12MHz.


Thanks!

Is the 8086 faster than 8088?.

I tested some programs, and 8088 seems to work just as "fast" as my old PS/2 did. So I guess it is just the same

I also found some problems with the mouse, in one or two games, but this is surelly a driver problem.

Programs not working in 8088 emulation:

-norton commander

-lemmings1

-titus the fox

When running them, the pc just stays forever in a black screen.
TheMadLynx
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Re: 8086 emulation

Postby TheMadLynx » Sun 01 Oct, 2017 8:39 pm

Mills wrote:Programs not working in 8088 emulation:

-norton commander

-lemmings1

-titus the fox

When running them, the pc just stays forever in a black screen.

I'm sure that it is a native 8088/86 behavior due to the lack of CPU instructions needed by complex programs created much later than a PC XT. Replacing the Intel 8088 CPU with a NEC V20 was the only known way to run such programs on actual hardware.
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omarsis81
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Re: 8086 emulation

Postby omarsis81 » Mon 02 Oct, 2017 2:35 am

I didn't have time to test those games, but according to MobyGames those titles should run on a 8088/6
http://www.mobygames.com/game/dos/lemmings/techinfo
http://www.mobygames.com/game/dos/titus ... k/techinfo
Mills
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Re: 8086 emulation

Postby Mills » Mon 02 Oct, 2017 10:23 pm

TheMadLynx wrote:
Mills wrote:Programs not working in 8088 emulation:

-norton commander

-lemmings1

-titus the fox

When running them, the pc just stays forever in a black screen.

I'm sure that it is a native 8088/86 behavior due to the lack of CPU instructions needed by complex programs created much later than a PC XT. Replacing the Intel 8088 CPU with a NEC V20 was the only known way to run such programs on actual hardware.


I used to play that games and used the norton commander file manager in my 8086 very well, so I still have to play with the config I think.
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ruben_balea
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Re: 8086 emulation

Postby ruben_balea » Tue 03 Oct, 2017 12:17 am

I've made some tests with Generic XT clone and IBM XT (both have 8088 CPU) with VGA video adapter and MS-DOS 6.22.

Norton Commander -> OK version 4 and therefore all versions up to 4 should work also, version 5 already requires a 286 or higher.
Lemmings 1 -> OK, of course at 4.77 MHz takes more time to load than at 16 MHz
Titus the Fox -> I don't have this game to test, but according to the user manual http://www.gamesdatabase.org/Media/SYSTEM/Amstrad_CPC/manual/Formated/Titus_the_Fox-_To_Marrakech_and_Back_-_1992_-_Titus_Software.pdf
floppy contains some copy protection system and you must have it inserted on the drive to start the game.
Perhaps you will need disk images of the 5-1/4" floppies to run it on most 8088 and 8086 machines because I think their BIOSes won't support 1.44MB drives but I'm not really sure of this...
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omarsis81
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Re: 8086 emulation

Postby omarsis81 » Tue 03 Oct, 2017 12:51 am

Most versions (if not all) that you get from abandonware sites only contains the files (not disk images) and cracked, so floppy protection can be easily circumvented
Mills
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Re: 8086 emulation

Postby Mills » Tue 03 Oct, 2017 10:16 am

ruben_balea wrote:I've made some tests with Generic XT clone and IBM XT (both have 8088 CPU) with VGA video adapter and MS-DOS 6.22.

Norton Commander -> OK version 4 and therefore all versions up to 4 should work also, version 5 already requires a 286 or higher.
Lemmings 1 -> OK, of course at 4.77 MHz takes more time to load than at 16 MHz
Titus the Fox -> I don't have this game to test, but according to the user manual http://www.gamesdatabase.org/Media/SYSTEM/Amstrad_CPC/manual/Formated/Titus_the_Fox-_To_Marrakech_and_Back_-_1992_-_Titus_Software.pdf
floppy contains some copy protection system and you must have it inserted on the drive to start the game.
Perhaps you will need disk images of the 5-1/4" floppies to run it on most 8088 and 8086 machines because I think their BIOSes won't support 1.44MB drives but I'm not really sure of this...


As omarsis81 says, most versions found on the internet are surelly cracked.. But I might have a non cracked copy, and that would explain it, so I'll try to find new versions.

Thanks!
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ruben_balea
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Re: 8086 emulation

Postby ruben_balea » Tue 03 Oct, 2017 3:39 pm

:!: Consider to not download it because this game is no longer abandonware, so abandonware sites will have now illegal copies or removed it, and on many countries even genuine abandonware software is illegal to download...
:idea: For those without original disks looking for it it's avaiable for sale at https://www.gog.com/game/titus_the_fox_to_marrakech_and_back for Windows (XP, Vista, 7, 8, 10), Mac OS X (10.9+) and Linux (Ubuntu 14.04, Ubuntu 16.04)

Under Windows if you still have the original disk(s) you can play it also with OpenTitus, simply download it, unpack it and copy game files into "titus" subfolder https://sourceforge.net/projects/opentitus/

And the launch screen says:
titus.png
titus.png (7.06 KiB) Viewed 1356 times


Prehistorik 2 has a similar screen:

Image

... and for fun I found this picture on Google:

Image

If the game was programmed on a AT 286 @ 12MHz perhaps the original game was compiled with 286 code (even unnoticed, for some compilers you must specify the destination CPU or they will generate code optimized for the CPU on which they're running) and later they made a version recompiled for PX/XT as they made versions for Amiga, Atari ST, Amstrad CPC, Game Boy, Game Boy Color...
A. Naim
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Re: 8086 emulation

Postby A. Naim » Tue 03 Oct, 2017 4:32 pm

Disclaimer: I Am Not A Lawyer. Depending on jurisdiction, I *think* it *might* be legal to download off the internet if you already own a copy.
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omarsis81
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Re: 8086 emulation

Postby omarsis81 » Tue 03 Oct, 2017 4:35 pm

Enough speculation! Let's face facts ;)
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lemmings.png
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omarsis81
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Re: 8086 emulation

Postby omarsis81 » Tue 03 Oct, 2017 5:51 pm

Regarding "Titus the Fox":

I tested a cracked copy of the game and:

- Works fine on a 286 and higher
- Crashes (black screen) after executing the COM file on any 8088 and 8086

All the manuals and web pages I read state that the game runs on a IBM PC or XT, so my conclusion is that the might be a bug with the 8088/6 emulation.
Unfortunately I don't own a real 8088/6 computer to test it with
Mills
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Re: 8086 emulation

Postby Mills » Tue 03 Oct, 2017 7:16 pm

omarsis81 wrote:Regarding "Titus the Fox":

I tested a cracked copy of the game and:

- Works fine on a 286 and higher
- Crashes (black screen) after executing the COM file on any 8088 and 8086

All the manuals and web pages I read state that the game runs on a IBM PC or XT, so my conclusion is that the might be a bug with the 8088/6 emulation.
Unfortunately I don't own a real 8088/6 computer to test it with


"Les adventures de Moktar" was the first version of titus the fox (I think...), so I used "moktar.exe" (it is the exe inside this version), and it loaded the title screen. Instead of fox, there is a picture of some guy... lol. After that it crashed :(.

About lemmings... I had a bad copy of it, very old copy, I don't know how I got it years ago, so that's why lemmings (1) does not work.

Norton comander is working (version 1.0).

Other games I tested to see if my old pc could run them, just for fun (using EGA-VGA):

-Another world: disable sound, and it is playable, as some people with real 8086 8 mhz told me, it works just a bit slower than the snes version. It even was compatible with MCGA (using the same 16 colours as VGA and the other ports) and EGA (using an ugly palette).
-Lemmings 2: works very well, even the scrolling is smooth in the game. It may become slow, if a lot of lemmings are exploding.
-Supaplex: I'm surprised how smooth is the scrolling in the menu. After that, gameplay is very slow, as I saw in a video working on a real 8086.
-Secret Agent: this works incredibly well, my real PC had an MCGA so this was not working because it uses EGA.
-Rick Dangerous II: works great, just as rick1 worked on my real pc, maybe a bit slow.
-Prince of persia: I could play this back in the day, the emulation is just perfect :).
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ruben_balea
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Re: 8086 emulation

Postby ruben_balea » Tue 03 Oct, 2017 11:13 pm

A. Naim wrote:Disclaimer: I Am Not A Lawyer. Depending on jurisdiction, I *think* it *might* be legal to download off the internet if you already own a copy.


Of course I was thinking on software that you do not own, if your already own it I don't see the difference between making a backup copy with your computer or download it already made, or to get a copy if your disks are damaged or in a format unreadable nowadays because you can't plug a 5.25" drive to your current computer.

And you own only just what came on the original disk or whatever media used for distribution, if your copy was the EGA version of the game you shouldn't expect a free upgrade to the VGA version :roll:

I simply don't want to promote downloading any software only on the basis that nobody is caring about it anymore, is really easy to look first on Google to see if it's again (or still) for sale somewhere, if it's really forgotten then shouldn't be any problem to download a copy.
A. Naim
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Re: 8086 emulation

Postby A. Naim » Wed 04 Oct, 2017 12:33 am

ruben_balea wrote:
A. Naim wrote:Disclaimer: I Am Not A Lawyer. Depending on jurisdiction, I *think* it *might* be legal to download off the internet if you already own a copy.


Of course I was thinking on software that you do not own, if your already own it I don't see the difference between making a backup copy with your computer or download it already made, or to get a copy if your disks are damaged or in a format unreadable nowadays because you can't plug a 5.25" drive to your current computer.

And you own only just what came on the original disk or whatever media used for distribution, if your copy was the EGA version of the game you shouldn't expect a free upgrade to the VGA version :roll:

I simply don't want to promote downloading any software only on the basis that nobody is caring about it anymore, is really easy to look first on Google to see if it's again (or still) for sale somewhere, if it's really forgotten then shouldn't be any problem to download a copy.

...I really don't know what your post has to do with mine, sorry. I wasn't responding to anyone in specific.
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leilei
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Re: 8086 emulation

Postby leilei » Wed 04 Oct, 2017 2:12 am

When I need a "cracked version" of a game I do have, it's pretty trivial to copy/install and run Rawcopy or Neverlock on it afterward (if it's old enough to be covered)...

I don't condone "abandonware" sites. They're often a case of false bug reports due to their lack of quality control (usually from ignorance) and/or the fact they regurgitate old scene rips and call it "preservation", some of those rips being buggier than the real thing. not to mention the definition of "abandonware" keeps mutating to broadly mean every old pc game as time goes on, rather than truly obscure titles that never had a commercial chance and freeware lost to the sands of time
Mills
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Re: 8086 emulation

Postby Mills » Wed 04 Oct, 2017 10:19 am

Well it's true a lot of abandonware sites make money with that games, and the games are sometimes bad copies that don't work well on original hardware. For example I had a bad lemmings copy, probably from an abandonware site I don't remember now.

I had many of these games in floppies back in the day, and they all worked perfect on the IBM PS/2, probably because they were not cracked/modified etc... (even if some of them were copies from a neighbour). I remember having to enter the codes for cool crock and monkey island every time I wanted to play :).

I kept some for nany years, and then I lost all of them.
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ruben_balea
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Re: 8086 emulation

Postby ruben_balea » Wed 04 Oct, 2017 5:46 pm

And it's a shame if you purchased something from big companies that are still alive and keep that software archived but won't provide you a replacement, like computer manufacturers, specially on laptops:
If the recovery partition gets lost because you install something, due to hard disk failure or virus corruption forget about your licensed OS even if there's a license sticker on the bottom and a serial number on the computer.
And you can't replace it with a generic copy because it's highly customized and most things won't work as before and the license may be no longer valid because you used a copy with different OEM KEYS.

:arrow: But back to the original problem (is PCem 8086 emulation working or not?) we need some quality control also.

Something like:

I do have the genuine media of type (X) of game or program (Y) and I do have the original computer model (Z)
When I put the game media (Y) on the drive (X) of my computer (Z) the game or program works fine.

For (X) and PC market you can assume cartridge, cassete, 5.25" floppy from 160KB to 1.2MB, 3.5" floppy from 720KB to 1.44MB, CD-ROM...

Then (Y) must be a RAW copy of the original media, 100% perfect, made with full knowledge and with the right tools.
(Y) can't be a copy that anybody can get on the internet and may not be good.
If (Y) is bootable or self loading on computer (Z) by any way before loading the operating system then you must configure PCem without any OS to prevent incompatibilities.
If (Y) requires an Operating System you must use the same operating system in PCem, with same drivers, same hard disk size and so on. If possible also a RAW copy of the bootable floppy or hard disk containing such OS.

If your computer (Z) has less than 640KB of RAM configure PCem to the same amount of RAM instead of the 640 that may be optionally available.
If your computer (Z) has 1MB of RAM configure PCem to 1MB of RAM and so on.
If your computer (Z) has 8086, 8088, 80186, 80188, V20, V30 CPU but has more than 640KB or 1MB of RAM then it must be using an EMS card, this may not be emulated yet in PCem.
If your computer (Z) has 80186, 80188, V20, V30 CPU it supports some 80286 instructions and can't be emulated by PCem with 8086/8088 CPU, in this case see if there's equivalent machine with 80286 in PCem.

After doing so if your game (or other software) doesn't work then maybe a BUG, you can report it to look for a solution. But maybe also something pending in PCem, so please see it that feature is already imlemented or not, PCem is still under development. Read this post about bug reports: https://pcem-emulator.co.uk/phpBB3/viewtopic.php?f=2&t=4
If you can't satisfy those requiriments please don't make possible false BUG reports until you are really sure it was not your fault.
Last edited by ruben_balea on Sun 08 Oct, 2017 6:31 pm, edited 1 time in total.
Fenix77
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Re: 8086 emulation

Postby Fenix77 » Fri 06 Oct, 2017 8:10 pm

Hello.

I think the only way to be sure the game, it`s not corrupt or damaged is buying the original disk if itºs avaiable or download it with a torrent application, although it may be not legal and might contain virus, old DOS virus will not affect modern systems, and some of them may contain the game without any crack.
A Crack utility can be used with them Neverlock or CrackAid for example.
The reason to do this is because some floppy disk may be too difficult and expensive to find and even if it's found it may contain sectors with errors.

The 8086 CPU can be up to 50% faster than the 8088, because the 8086 has 16 bit memory bus and the 8088 8-bits. notwithstanding both of them has 16-bit internally and 20 bits of memory directions.

As for EMS memory, it´s not a big problem for games developed for 8088/8086 XT because that games uses Conventional memory only.
The apllications that can use EMS memory are applications such as Lotus 1-2-3, Windows 2.0 and some disk caching utilities,such a PC-Kwick.


The games that require EMS memory such as Incredible Machine II and Black Thorne, requires at least an 80386.

This is because

1. Uses 386 real mode instructions
2. Requires some VCPI fuction (Virtual 8086 mode)
3. Uses an amount of registers not supported by any EMS board.

Support for EMS was added in Laser XT machines (in PCEM source and 86box)

I tested Manifest application included in QRAM 2.02 with LaserXT (added by Greatpsycho) and Award 286, which has an SCAT chipset.
And QEMM 9.0 with an 486 DX/2 66 mhz.

On Laser XT Manifest only sees the 64kb Page Frame. (There is 140kb of free UMB but it can not be mapped with EMS 3.2 hardware).
The EMM.SYS driver say '4.0' when loading, but it is 3.2 at hardware level, i discovered that because the OEMSTEST Program created by Douglas Boling show that 4.0 fuctions are not supported. Nevertheless this driver grants compatibility with Windows 2.0 and 2.11.

The Award 286 wich support the EMS 4.0, it also detects 384kb of the conventional memory as 'mappeable' (this means, this area can be copied back an forth the conventional to EMS memory and then from EMS to convetional, (this is called 'Large Page Frame'). And also 128kb of UMB can be used.
On the 486 QEMM can map nearly the entire 640kb area, and even map the smaller 4kb memory blocks can be used as UMB memory.

This is why the games that requires more than 64kb of EMS requires and 80386 and a software such as EMM386/QEMM/386MAX to run. It is faster because uses the 32 bits capabities of the CPU, can map device drivers in UMB memory, so more conventional memory is avaiable and no extra hardware is required.

There is a good book from 1992 that explains the difference between the EMS 3.2 and 4.0 memory boards, and the 'new' (for it´s day) memory magement capabilities of the 80386, it can emulate EMS memory using XMS, by enabling the V86 mode, in this mode the CPU intercepts real mode instructions and manage it inside the protected mode, solving the problem of the 286 which needed a reset to return to real mode from the protecetd mode.

Here is it https://archive.org/details/DOS_Beyond_640K_2nd_edition
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ruben_balea
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Re: 8086 emulation

Postby ruben_balea » Sun 08 Oct, 2017 6:40 pm

I edited my previous post to replace "game (Y)" by "game or program (Y)" because I was really thinking on any software...

Therefore EMS needs to be still considered and EMS provided by chipsets or 386+ CPU doesn't help if you want to emulate systems without those chipsets or CPU.
In this case IBM PS/2 Model 30-8086 lacks emulation of the IBM 2MB EXPANDED MEMORY ADAPTER #2685193 or other model/brand/size EMS card.
Emulating any of those cards will be enough for all systems lacking onboard EMS, so for me it is a realistic feature for future PCem versions...
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ruben_balea
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Re: 8086 emulation

Postby ruben_balea » Mon 09 Oct, 2017 5:03 pm

A. Naim wrote:
ruben_balea wrote:
A. Naim wrote:Disclaimer: I Am Not A Lawyer. Depending on jurisdiction, I *think* it *might* be legal to download off the internet if you already own a copy.


Of course I was thinking on software that you do not own, if your already own it I don't see the difference between making a backup copy with your computer or download it already made, or to get a copy if your disks are damaged or in a format unreadable nowadays because you can't plug a 5.25" drive to your current computer.

And you own only just what came on the original disk or whatever media used for distribution, if your copy was the EGA version of the game you shouldn't expect a free upgrade to the VGA version :roll:

I simply don't want to promote downloading any software only on the basis that nobody is caring about it anymore, is really easy to look first on Google to see if it's again (or still) for sale somewhere, if it's really forgotten then shouldn't be any problem to download a copy.

...I really don't know what your post has to do with mine, sorry. I wasn't responding to anyone in specific.


Please excuse me as I never wanted to criticize your post, I used it only as a reference to explain better my own thoughts about about this theme.
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ruben_balea
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Re: 8086 emulation

Postby ruben_balea » Wed 01 Nov, 2017 11:58 pm

Titus runs fine on VB8086 emulator on autodetected CGA mode:

titus_vb8086_cga.png
titus_vb8086_cga.png (16.86 KiB) Viewed 837 times


It can be forced to VGA mode with /V switch and it does work too:

titus_vb8086_vga.png
titus_vb8086_vga.png (10.56 KiB) Viewed 837 times


But if forced to EGA (/E) it gets stuck on video mode Dh:

titus_vb8086_ega.png
titus_vb8086_ega.png (6.6 KiB) Viewed 837 times


Screenshot shows MS-DOS booting because it's being loaded from a bootdisk with SHELL=FOX.COM parameter in config.sys* the game changes mode from 3h to Dh but the screen remains unchanged.
* There's no room on a 720KB boot floppy for all files of the game without deleting first command.com...
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ruben_balea
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Re: 8086 emulation

Postby ruben_balea » Thu 02 Nov, 2017 12:01 am

In PCem with 8088/8086 displays the same as in VB8086 with any video card and any Titus command line swithces:

titus_PCem-808x.png
titus_PCem-808x.png (7.45 KiB) Viewed 837 times


With 80286 or higher it runs fine in CGA, EGA and VGA:

titus_PCem-80286.png
titus_PCem-80286.png (39.13 KiB) Viewed 837 times


In Retro http://jorisvr.nl/article/retro runs well in CGA mode. EGA and VGA aren't implemented in Retro.

titus_retro_cga.png
titus_retro_cga.png (13.48 KiB) Viewed 837 times
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ruben_balea
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Re: 8086 emulation

Postby ruben_balea » Thu 02 Nov, 2017 12:32 am

Finally in PCE/ibmpc http://www.hampa.ch/pce/pce-ibmpc.html works peerfectly on all video modes and 8088/8086/80188/80186 CPU @ 4.77MHz

titus_pce-ibmpc_cga.png
titus_pce-ibmpc_cga.png (14.09 KiB) Viewed 836 times



titus_pce-ibmpc_ega.png
titus_pce-ibmpc_ega.png (18.51 KiB) Viewed 836 times



titus_pce-ibmpc_vga.png
titus_pce-ibmpc_vga.png (37.68 KiB) Viewed 836 times


Using this configuration: (Here I mean PCE config, NOT PCem config)

Code: Select all

C:\msys64\home\user\PCE-IBMPC>bin\pce-ibmpc.exe -v -c pce-5160.cfg -l pce.log -g vga -r
pce-ibmpc version 20170208-df19414
Copyright (C) 1995-2012 Hampa Hug <hampa@hampa.ch>
CONFIG:   file="pce-5160.cfg"
SYSTEM:   model=5160 floppies=2 sw1=00/00 patch-init=0 patch-int19=0
RAM:      addr=0x00000000 size=655360 file=<none>
ROM:      addr=0x000f0000 size=65536 file=<none>
ROM:      addr=0x000c0000 size=32768 file=<none>
CPU:      model=8088 speed=1X
DMAC:     addr=0x00000000 size=0x0010
PIC:      addr=0x00000020 size=0x0002
PIT:      addr=0x00000040 size=0x0004
PPI:      addr=0x00000060 size=0x0004
SPEAKER:  volume=250 srate=44100 lowpass=8000 driver=sdl:lowpass=0
TERM:     driver=sdl ESC=ESC aspect=4/3 min_size=512*384 scale=1 mouse=[1/1 1/1]
VIDEO:    device=vga
VIDEO:    VGA io=0x03b0 addr=0xa0000
VIDEO:    VGA irq=2 (disabled)
ROM:      addr=0x000c0000 size=32768 file=rom/ibm-vga-1986-10-27.rom
DISK:     drive=0 type=auto blocks=1440 chs=80/2/9 rw file=Titus_the_Fox_To_Marrakech_CRK.ima
FDC:      addr=0x000003f0 irq=6 accurate=1 eot=1 drv=[0 1 2 3]
SERPORT:  COM1 addr=0x03f8 irq=4 multichar=r=1/w=1 uart=8250
SERPORT:  COM1 driver=stdio:file=ser1.out:flush=1
Load:     file=rom/ibm-vga-1986-10-27.rom format=binary addr=0x000c0000
Load:     file=rom/ibm-xt-1986-05-09.rom format=binary addr=0x000f0000
[0000:0000] reset pc
[F000:FFF0] reset keyboard
[F000:F9ED] reset keyboard
[F000:F9ED] reset keyboard


And with that configuration PCE/ibmpc needs all the CPU power of the host computer to emulate 4.77MHz so I didn't tried higher speeds...
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ruben_balea
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Re: 8086 emulation

Postby ruben_balea » Thu 02 Nov, 2017 1:08 am

:?: It's enough to say there's a BUG in the PCem 8086 emulation if other emulator(s) can run it flawlessly?
A problem with a single game may not seem important for now but it may affect some other software, if someone wants to investigate it I can provide the 8086 executable because all other files should be the same or at least interchangeable between all game versions.

:idea: There's at least one version of the game executable which seem to have some 286 code and since those executables are encrypted and compressed those few 286 instructions can go unnoticed or cause additional headaches.
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omarsis81
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Re: 8086 emulation

Postby omarsis81 » Thu 02 Nov, 2017 5:21 pm

ruben_balea wrote::?: It's enough to say there's a BUG in the PCem 8086 emulation if other emulator(s) can run it flawlessly?

http://www.hampa.ch/pce/ seems sturdy, but I find it difficult to operate it, take a look if you want
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ruben_balea
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Location: Spain

Re: 8086 emulation

Postby ruben_balea » Thu 02 Nov, 2017 9:36 pm

omarsis81 wrote:
ruben_balea wrote::?: It's enough to say there's a BUG in the PCem 8086 emulation if other emulator(s) can run it flawlessly?

http://www.hampa.ch/pce/ seems sturdy, but I find it difficult to operate it, take a look if you want

Well, I meant if someone wants to investigate in PCem why it does not work in PCem... I put the log (oops I called it config) of PCE/ibmpc simply for those interested on what hardware it was emulating on those screenshots.
I offer the 8086 executable because it's like a problem with 8086 emulation in PCem, and it seems to work at least for one type of video card on the few emulators that can emulate a 8086 without 80186+ instructions, to not waste time trying a 286 executable by mistake.
SEGStriker
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Re: 8086 emulation

Postby SEGStriker » Sun 05 Nov, 2017 10:14 am

There are several utils for 8086 or 80286 class CPUs:

Hiram.sys - HiRAM is a memory manager introduced since DOS 5 (MS-DOS, DR-DOS). Use of upper memory areas (UMBs) also on 8086 and 80286 PCs with corresponding memory expansion cards and thus allows the free. Can increase DOS memory to over 620KByte.

EMM286.EXE - EMM286 is an Expanded Memory LIMulator for an AT-Class system, or other 286 compatible. Provides both an EMM driver and command line functions in one executable file. All functions of the LIM EMS 4.0 specification dated October 1987 are supported except DMA.

UMBPCI.SYS - UMBPCI.SYS is a FREEware MS-DOS 5.00/6.xx, DR-DOS, Novell DOS, Caldera Open DOS and MS Windows 9x/3.xx Upper Memory Area (UMA) access driver (MS HIMEM.SYS extender) for Intel, FIC VIA (Apollo), ALi (Aladdin) and SiS PCI/AGP chipsets, supporting Pentium, Pentium Pro, Pentium II/III, AMD and Cyrix CPUs.

There are some others similar tools.
SarahWalker
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Re: 8086 emulation

Postby SarahWalker » Sun 05 Nov, 2017 5:18 pm

Fixed in rev 920.

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