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Toshiba T1200 emulation

Posted: Mon 15 Jan, 2018 3:34 pm
by Fenix77
Hello.

First, I'd like to thanks to all the people that work on the project, those added new emulated machines and those created the guide to compile the SVN branch of PCEM.

I tested Thosiba T1000 and worked ok, so far. I'd like to have T1200 emulation (if it's possible) because it has:

-20 mb hard disk (instead of DOS in ROM)
-8086 CPU running at 4.77/9.54 mhz
-1 Mb RAM (640 kb conventional + 384 kb Hard Ram/ LIM EMS 3.2)
-Upgradable to 2 Mb (640 conventional + 1408 kb Hard Ram / LIM EMS 3.2).

I saw in Youtube some T1200 models and they have the same screen than T1000 and Hard-RAM is fuction is near the same.
The hard disk makes easier to install software.

Back in the day the T1000 was cheaper U$S 1000 vs U$S 2200 of the Toshiba T1200 and the battery of T1000 lasted much more (about 180 min vs 75 min.).

PD: I found a small bug. It happen in ROM DOS 2.11 of both Toshiba T1000 an Tandy 1000 HX. Some programs lock up the emulated computers, but works correctly under DOS 3.2/3.3.

-FreeDOS Edit and MEM external command locks the system. The only solution it's reboot (works on Thoshiba DOS 3.3)
-4DOS version 2.21 (Sharware 1989, it's not the freeware 4DOS 8.00) 4dos88.exe works but 4dos.com lock's up the system too. (works on Thoshiba DOS 3.3 and uses 64kb of EMS if it's avaiable))
-Block 'o Mania: Block.exe generates and exception but cgablock.exe works. The game works too (i played until level 5).

Games I tested and works:
-Tetris (Spectrum Holobyte 1989)
-Welltris (it has an inverse CGA mode, it makes the game to look better (white foreground and black background).
-Outrun
-Block 'o Mania

Microsoft Works 2.0. I installed it on 3.5 720 kb floppy from the original installer. Work ok in CGA graphics mode with mouse.

Thanks again!

Re: Toshiba T1200 emulation

Posted: Mon 15 Jan, 2018 5:48 pm
by SarahWalker
-FreeDOS Edit and MEM external command locks the system. The only solution it's reboot (works on Thoshiba DOS 3.3)
-4DOS version 2.21 (Sharware 1989, it's not the freeware 4DOS 8.00) 4dos88.exe works but 4dos.com lock's up the system too. (works on Thoshiba DOS 3.3 and uses 64kb of EMS if it's avaiable))
-Block 'o Mania: Block.exe generates and exception but cgablock.exe works. The game works too (i played until level 5).
Do all of these run on disc-based DOS 2.11? 2.11 is pretty ancient even by these program's standards.

Re: Toshiba T1200 emulation

Posted: Mon 15 Jan, 2018 6:35 pm
by Fenix77
Hello.

In both emulated machines Tandy 1000 HX and Toshiba T1000, I booted from ROM DOS 2.11. May be it works differently than standard DOS 2.11
Both of these DOS versions have been modified to support 3.5 720 kb floppy disks. As far as i know PC-DOS 2.0-2.11 supports only 5.25 floppys up to 360 kb (ej 160/180/320/360 kb) no 3.5 or high density.
Hard Disk support up to 16 mb and only one partition. Toshiba T1000 can have drivers C and D. C as Rom drive and D as Hard-Ram. Also it has Vdisk.sys driver file in drive C, but that utility is included in standard PC-DOS 3.0 or higher.

Re: Toshiba T1200 emulation

Posted: Tue 16 Jan, 2018 12:06 am
by JohnElliott
You can configure the T1000 with an XTIDE drive if you'd rather have a conventional hard drive than the ROM drive.

Or rather, you could if that didn't crash PCEM. Culprit is line 36 of vid_t1000.c; it's trying to do a device_get_config_int(), but with the XTIDE present it tries to read the setting from the XTIDE device rather than the screen device. If that line's commented out it all seems to work.

Re: Toshiba T1200 emulation

Posted: Mon 29 Jan, 2018 10:33 pm
by JohnElliott
I've now submitted a patch to implement T1200 emulation and fix the crash when using the T1000 with XTIDE.

Re: Toshiba T1200 emulation

Posted: Tue 30 Jan, 2018 6:51 am
by Fenix77
Hello.

Thank you!. The T1200 it's a very complete XT laptop and a great addition. By the way, I recently found some info i did not know earlier.
I read that Toshiba T1200, among other XT based laptops, uses a hard disk contoller developed by JVC, but it's not a standard MFM/RLL XT controller. Some behaviors are different.
I found a blog here is the part 1 https://knm.org.uk/blog/2017/04/the-jvc ... ce-part-1/.
And the part 2 https://knm.org.uk/blog/2017/04/the-jvc ... ce-part-2/.

I know sometimes the emulation of some pieces of hardware can be nearly impossible to implement because the fuctions are not documented.

I'm not a programmer, but the author describes he has a working Victor V86P laptop and he is trying to "guess" how it works making int 13 BIOS calls with C++.
The author also says there is very scarce information about this particular controller.

I don't know if, meanwhile, Xebec or another XT controller can be used in PCEM with T1200, until the JVC emulation is implemented.

Thanks again!

PD: I read the T1200 patch file the CPU is defined as an 8088 but the real machine had an 8086 and can be configured at 4.77/9.54 Mhz. The basic ram memory configuration is 1MB, 640 conventional +384 kb LIM EMS or Hard Ram, or 1408kb if it's upgraded to 2MB with a propietary Ram card expansion, like the T1000 768kb Ram card.

PD:I tested the T3100 640x400x2 video modes with a Space Quest 3 using a graphics driver distributed by sierra but developed by unrelated authors and the game work flawlessly!. (it doubles the standard CGA 640x200x2)

This emulated machine works perfectly, Thanks for your effort and time!

I attached the drv files for SCI sierra games for anyone, it's intrested to test them.

Re: Toshiba T1200 emulation

Posted: Tue 30 Jan, 2018 10:10 am
by JohnElliott
I've dumped the firmware ROM from the hard drive controller (looks like Z80 to me) but didn't try to implement it in the patch. It only supports two drive sizes (10Mb or 20Mb) so you'd be better off using one of the existing controllers already implemented in PCEM, such as XTIDE.