Search found 105 matches

by JohnElliott
Thu 23 Mar, 2017 10:58 pm
Forum: General
Topic: PC-DOS 1.10 and PCem v12
Replies: 64
Views: 16343

Re: PC-DOS 1.10 and PCem v12

Good. But your theory can be proved only via disassembling the IBM PC-DOS 1.10 FORMAT.COM I have disassembled the PC-DOS 1.10 FORMAT.COM. Anyone who wants the IDA database, drop me a line. The program's divided very clearly into two modules: the first 2k are the machine-independent bit, dealing wit...
by JohnElliott
Wed 22 Mar, 2017 8:41 pm
Forum: Development
Topic: [Patch] MDSI Genius video card
Replies: 11
Views: 3714

Re: [Patch] MDSI Genius video card

While developing it I used the IBM XT system, with MS-DOS 3.3. The genxt BIOS reports 704k RAM, so I think it's trying to extend conventional RAM into the memory used by the Genius card. And then when GMC_ANSI or Windows start using that RAM, important things get overwritten. That suggests the card ...
by JohnElliott
Sun 19 Mar, 2017 12:27 am
Forum: Development
Topic: [Patch] MDSI Genius video card
Replies: 11
Views: 3714

Re: [Patch] MDSI Genius video card

Pre-VGA only. Mainly cards for which GEM or GSX drivers exist, because I'm familiar enough with those drivers to disassemble them and grok what they're doing. I don't have that same level of knowledge with Windows 1.0x video drivers, for example (it doesn't help that, as I recall, they use self-modi...
by JohnElliott
Sat 18 Mar, 2017 11:48 pm
Forum: Development
Topic: [Patch] MDSI Genius video card
Replies: 11
Views: 3714

[Patch] MDSI Genius video card

This patch is a bit theoretical, because I don't have the original video card (a mono portrait card, resolution 728x1008). What I do have is some drivers. Windows 1.04 and GEM 3 both come with drivers for this card, and there's a driver for a PS/2 version of the card at mpoli.fi . Despite being for ...
by JohnElliott
Mon 06 Mar, 2017 11:03 am
Forum: Development
Topic: ST-412/ST-506/ESDI hard drive emulation?
Replies: 51
Views: 16761

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

For flexibility, perhaps SCSI is the way to go -- the Future Domain TMC-850 was quite a common 8-bit SCSI card. The 8.2 BIOS is the best one to use on an XT as later versions don't hook INT 19h and rely on the motherboard BIOS to know about booting from hard drives.
by JohnElliott
Sat 17 Dec, 2016 5:30 pm
Forum: Development
Topic: [Patch] Wyse 700 graphics support
Replies: 7
Views: 3926

Re: [Patch] Wyse 700 graphics support

OK, here's a path to vid_wy700.c that seems to improve matters for me.
by JohnElliott
Fri 16 Dec, 2016 10:42 pm
Forum: Development
Topic: [Patch] Wyse 700 graphics support
Replies: 7
Views: 3926

Re: [Patch] Wyse 700 graphics support

I've put a copy of the character ROM at http://www.seasip.info/tmp/wy700.rom
by JohnElliott
Fri 16 Dec, 2016 10:40 pm
Forum: Development
Topic: [Patch] Wyse 700 graphics support
Replies: 7
Views: 3926

[Patch] Wyse 700 graphics support

The Wyse 700 video card has a fixed-resolution 1280x800 display, with a 16x16 character bitmap.

I've tested this against real hardware with a handrolled test utility and with GEM.
by JohnElliott
Sun 30 Oct, 2016 6:28 pm
Forum: Development
Topic: Building on Linux Mint... Error
Replies: 3
Views: 2498

Re: Building on Linux Mint... Error

This happens to me when I try to build Linux pcem from source. What I did to fix it, the most recent time, was: * Create a shell script called "reconfig", containing these commands: #! /bin/sh set -x aclocal autoheader libtoolize automake --foreign --add-missing --copy autoconf Then run it: chmod +x...
by JohnElliott
Mon 17 Oct, 2016 2:53 pm
Forum: Development
Topic: [Patch] Plantronics Colorplus support
Replies: 7
Views: 4033

Re: [Patch] Plantronics Colorplus support

Apparently snow was a possibility: "With Flight Simulator, the Paradise MultiDisplay worked perfectly, but the Plantronics Color-Plus board produced a significant amount of color snow on an RGB monitor" . When I was developing the patch, I tested against the 'Plantronics mode' of the Paradise EGA ch...
by JohnElliott
Sun 09 Oct, 2016 8:17 pm
Forum: Development
Topic: [Patch] Plantronics Colorplus support
Replies: 7
Views: 4033

Re: [Patch] Plantronics Colorplus support

Yes (apart from the bits copied and pasted from the CGA driver).
by JohnElliott
Sun 09 Oct, 2016 7:38 pm
Forum: Development
Topic: [Patch] Plantronics Colorplus support
Replies: 7
Views: 4033

[Patch] Plantronics Colorplus support

Another old-world video card; the Colorplus is a superset of CGA, with two extra graphics modes (320x200 16-colour and 640x200 4-colour).
by JohnElliott
Sat 08 Oct, 2016 9:45 pm
Forum: General
Topic: [Bug] No A20 wrap on XT
Replies: 1
Views: 1137

[Bug] No A20 wrap on XT

On a genuine XT, addresses above 0xFFFFF wrap round: C:\>debug -dc:0,f 000C:0000 EA 60 11 32 01 10 32 01-FC 10 32 01 43 C0 FF EF .`.2..2...2.C... -df01d:fef0,feff F01D:FEF0 EA 60 11 32 01 10 32 01-FC 10 32 01 43 C0 FF EF .`.2..2...2.C... - On PCEM's XT emulation, they don't: C:\>debug -dc:0,f 000C:0...
by JohnElliott
Wed 03 Feb, 2016 9:07 pm
Forum: Development
Topic: [PATCH] Hercules InColor
Replies: 1
Views: 1729

[PATCH] Hercules InColor

I'd better start by apologising in advance for my unfamiliarity with the PCEM codebase; there are some places (such as where I call video_blit_memtoscreen() ) I've no real understanding of what the parameters mean, and just fiddled with them until the output looked right. This patch (against 10.1) a...
by JohnElliott
Mon 01 Feb, 2016 7:16 pm
Forum: General
Topic: Hercules crash under Linux
Replies: 1
Views: 1653

Hercules crash under Linux

PCEM v10.1 under Linux System: IBM 5160 Video card: Hercules pcem crashes in allegro_blit_memtoscreen_8 (x=0, y=1000, w=720, h=200): (gdb) bt #0 0x00000000004e8a7a in allegro_blit_memtoscreen_8 (x=0, y=1000, w=720, h=200) at allegro-video.c:98 #1 0x0000000000556788 in hercules_poll (p=0x2e5a410) at ...