VTech Laser XT Series improvements

Discussion of development and patch submission.
Greatpsycho
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VTech Laser XT Series improvements

Postby Greatpsycho » Mon 29 May, 2017 1:38 pm

This patch applies load IBM-BASIC rom if it is available. Laser XT series can be coupled with IBM-BASIC.

LTXT_BASIC.png
LTXT_BASIC.png (12.84 KiB) Viewed 1321 times

LXT3_BASIC.png
LXT3_BASIC.png (12.77 KiB) Viewed 1321 times
Attachments
mem.c.patch
Load IBM-BASIC rom if it is available. Rewritten against commit 5e03bfb.
(4.96 KiB) Downloaded 14 times
Greatpsycho
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Re: VTech Laser XT Series improvements

Postby Greatpsycho » Sat 03 Jun, 2017 6:56 am

This patch applies experimental EMS implement for VTech Laser XT series.

Patch and test disk image attached.

Please note this revision supports only one EMS board so can use up to 512KB EMS memory and base address of EMS I/O port is fixed at x208 and x209 so I/O address option of EMM.SYS driver is only allowed I0.

LaserXT_EMS.png
LaserXT_EMS.png (14.19 KiB) Viewed 1199 times
Attachments
laserxt_patch_rev1.tgz
Patch to experimental EMS support on Laser XT series.
(4 KiB) Downloaded 23 times
SarahWalker
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Re: VTech Laser XT Series improvements

Postby SarahWalker » Sun 04 Jun, 2017 5:03 pm

Thanks for the patches, but could you please stop uploading images containing MS-DOS? It is copyrighted material that I'd rather not have on the site.
SarahWalker
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Re: VTech Laser XT Series improvements

Postby SarahWalker » Sun 04 Jun, 2017 5:14 pm

IBM BASIC changes committed at rev 753.
SarahWalker
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Re: VTech Laser XT Series improvements

Postby SarahWalker » Sun 04 Jun, 2017 8:46 pm

EMS doesn't seem to work when a hard disc controller is enabled.
Greatpsycho
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Re: VTech Laser XT Series improvements

Postby Greatpsycho » Mon 05 Jun, 2017 11:07 am

SarahWalker wrote:EMS doesn't seem to work when a hard disc controller is enabled.


You should add M2(M2~M7 is suitable) option to EMM.SYS like below if you use hard disk controller.
DEVICE=EMM.SYS M2

LaserXT_with_hard_disk.png
LaserXT_with_hard_disk.png (16.77 KiB) Viewed 1084 times


If you want to know about the appropriate options, please read the following document.
emm.txt
(8 KiB) Downloaded 28 times
SarahWalker
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Re: VTech Laser XT Series improvements

Postby SarahWalker » Mon 05 Jun, 2017 7:59 pm

Committed at rev 755.
Fenix77
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Re: VTech Laser XT Series improvements

Postby Fenix77 » Sun 03 Sep, 2017 5:42 am

Hello.

I don't know if this post is closed.

I recently discovered tath the Vtech Laser XT/3 has an 8086 Cpu not an 8088 like the Vtech Laser Turbo XT.

If i recall correctly. the EMS memory chips can be installed in 256kb incrementens in the 8088 system (example 256/512/768/1024 kb) and 512 kb in the 8086 (512/1024kb).
Here is teh manual http://www.minuszerodegrees.net/manuals/VTech/VTech%20Laser%20XT3%20-%20Operations%20Manual.pdf

I would like to ask if it is possible to implement the support of 1MB of EMS for the Laser XT models, or it can break the emulator.
I'm not a programmer and I don't know much about how PCem was written (i read about only 208h port is implemented.)

Is it posible to have a separate Coventional and EMS memory configurations for Laser XT? I know it is low priority but the manual states that the minimum conventional memory is 512kb. So its is possible to have 512 or 640 kb conventional memory plus EMS memory.


Seem interesting to me to comparing LaserXT with the Award 286 with the SCAT chipset for two reasons.

1. See how differs the the Laser XT wich supports the EMS v3.2 (with the 4.0 driver) spec vs the SCAT chipset tha support EMS v4.0 which is a superset of the v3.2.
2. Both of them are pre-386 systems. This implies that they does not use the Virtual 8086 mode via EMM386 to emulate EMS.

-The software i tested is Windows 2.03 (which support EMS) and PC-Kwick disk cache included in DR-DOS 6 and ViewMax.
It can do some task switching using EMS memory.

The EMS 4.0 spec was better for more complex aplications like Word for Windows 1.1 an Excel.

Thanks in advance.
Greatpsycho
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Re: VTech Laser XT Series improvements

Postby Greatpsycho » Fri 03 Nov, 2017 8:38 am

Fenix77 wrote:Hello.

I don't know if this post is closed.

I recently discovered tath the Vtech Laser XT/3 has an 8086 Cpu not an 8088 like the Vtech Laser Turbo XT.

If i recall correctly. the EMS memory chips can be installed in 256kb incrementens in the 8088 system (example 256/512/768/1024 kb) and 512 kb in the 8086 (512/1024kb).
Here is teh manual http://www.minuszerodegrees.net/manuals/VTech/VTech%20Laser%20XT3%20-%20Operations%20Manual.pdf

I would like to ask if it is possible to implement the support of 1MB of EMS for the Laser XT models, or it can break the emulator.
I'm not a programmer and I don't know much about how PCem was written (i read about only 208h port is implemented.)

Is it posible to have a separate Coventional and EMS memory configurations for Laser XT? I know it is low priority but the manual states that the minimum conventional memory is 512kb. So its is possible to have 512 or 640 kb conventional memory plus EMS memory.


Seem interesting to me to comparing LaserXT with the Award 286 with the SCAT chipset for two reasons.

1. See how differs the the Laser XT wich supports the EMS v3.2 (with the 4.0 driver) spec vs the SCAT chipset tha support EMS v4.0 which is a superset of the v3.2.
2. Both of them are pre-386 systems. This implies that they does not use the Virtual 8086 mode via EMM386 to emulate EMS.

-The software i tested is Windows 2.03 (which support EMS) and PC-Kwick disk cache included in DR-DOS 6 and ViewMax.
It can do some task switching using EMS memory.

The EMS 4.0 spec was better for more complex aplications like Word for Windows 1.1 an Excel.

Thanks in advance.


This patch does the following that you pointed out.
- Changed LaserXT/3 processor to 8086.
- Changed LaserXT/3's minimum memory size to 512KB and granularity to 128KB.
- Changed EMS size granularity to 256KB on Laser Turbo XT and 512KB on LaserXT/3. Base memory size is calculated automatically. 768KB configuration is now applied 512KB+256KB in Laser Turbo XT and 256KB+512KB in LaserXT/3. And 1024KB configuration is now applied 512KB+512KB.
- The mem_set_mem_state() function call for above of 1MB is called only when the memory size is more than 1024KB. It solves the problem that the system doesn't start properly when the memory size is set between 640KB and 1024KB in LaserXT series and many kinds of 286 and 386 systems.
Attachments
laserxt_patch_rev2.tar.gz
Patch for LaserXT series.
(1.4 KiB) Downloaded 9 times
Last edited by Greatpsycho on Fri 03 Nov, 2017 2:34 pm, edited 1 time in total.
Fenix77
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Re: VTech Laser XT Series improvements

Postby Fenix77 » Fri 03 Nov, 2017 1:57 pm

I thought i was not possible to add 1MB EMS memory support because the complexity of the algorithm required.
So now it's very close to the real machine.

May be some day printer emulation might be added (using some kind of passtrought, like Vdos Plus) for a complete emulation.

It's an awesome work.
Many Thanks!
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omarsis81
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Re: VTech Laser XT Series improvements

Postby omarsis81 » Fri 03 Nov, 2017 5:51 pm

Just out of curiosity...
The Laser XT and the Laser Compact XT have the same chipset, BIOS and video card? Would it make sense to add the Compact XT?
SarahWalker
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Re: VTech Laser XT Series improvements

Postby SarahWalker » Sat 04 Nov, 2017 1:46 pm

Committed at rev 916.
Fenix77
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Re: VTech Laser XT Series improvements

Postby Fenix77 » Sat 11 Nov, 2017 3:45 pm

The Laser XT/3 was changed to 8086 correctly. But the memory granularity was not added in any of the Laser XT machines, however the 512kb was established as the minimum, like the real hardware.
I know will be a difficult task to add all the memory combinations of Convetional/EMS memory of the real hardware because there is only one memory counter.

Memory configurations of Connventional/EMS for Laser XT/3 can be 6 taking into account 0 EMS as a memory configuration, and 10 configurations for Laser Turbo/XT with 8088, because it supports the use of only one EMS chip.

In the Laser XT/3 with 8086 to use EMS memory the two chips must have at least 256kb of memory, because each EMS chip uses a bus of 8 bits. I know it may be difficult to implement the use of two EMS chips, but maybe only one EMS chipset emulation can be used until a more complex and accurate emulation can be added.

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