[Bug] Commodore SL386SX-25 garbagge in the screen

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Fenix77
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Joined: Fri 01 Sep, 2017 11:59 am

[Bug] Commodore SL386SX-25 garbagge in the screen

Post by Fenix77 »

Hello!

I have been testing the recently added commodore SL386SX-25 machine. It is an interesting addition. The AVGA2 chip seems to be faster than the OTI-67 and Trident 8900 at 800x600 256-color resolution.
However,I found some bugs
I found a bug in the 800x600 256 colors video mode with the integrated AVGA2 video card and drivers in Windows 3.1 The corrupted image appear when an up or down scroll button is pressed. For example in Paintbrush or any selection made with the scroll buttons. It does not affect the 1024x768 16-color resolution.

I found that the Tandy 1000 RSX has the same AVGA2 card so I am using these win 3.1 drivers, because the original installation disk is very hard to find.

2. In the Setup BIOS configuration screen the amount of main RAM memory is always 16mb in spite of being correctly detecting in the startup screen.

3. Question: This machine has a SCAMP chipset, I know it is not emulated yet, but I found a VEMM.SYS device driver and a VEMM.ASM file that seem to be the source code in assembler.

This driver is for this VLSI chipset?

I don’t know if its information can be useful to implement the emulation of the chipset.

I also found a site that says it has the installation disk for this machine. It has a list of the files contained and exist an EMS driver called VLEMM.SYS with a size of 17kb. But unfortunately the disk is not there anymore to be downloaded.
here is the site:[url] http://www.video-drivers.com/drivers/37/37757.htm[/url]

I attach the sceenshot and the driver here, I don't know if it could be useful.

Thanks!
Attachments
VEMM.zip
(52.2 KiB) Downloaded 314 times
bug AVGA2.png
bug AVGA2.png (335.05 KiB) Viewed 7008 times
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ruben_balea
Posts: 191
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Location: Spain

Re: [Bug] Commodore SL386SX-25 garbagge in the screen

Post by ruben_balea »

Try the AVGA2 drivers or even loading in autoexec.bat the Cirrus Logic TSR BIOS 1.2 which may include some fixes, I don't know if it can help for Windows 3.x drivers. It seems to provide VESA 1.02 extensions and make the card working as a Cirrus Logic GD5420 on Windows 9x. But I haven't tried anything :roll:

[url]https://drive.google.com/file/d/1U58YPbdGtnbQsiunyWb06M-CNECXiEJI/view?usp=sharing[/url]
Fenix77
Posts: 80
Joined: Fri 01 Sep, 2017 11:59 am

Re: [Bug] Commodore SL386SX-25 garbagge in the screen

Post by Fenix77 »

Hello!

Thank you for these drivers!. The AVGA2 drivers are near impossible to find on the web. I will test that VESA bios.

I barely managed to find The AVGA1, first I found driver disk for DOS/Win 3.0 in a Russian blog, then the AVGA 800x600 16-color Win 3.1 driver in a FTP site.
and last I downloaded the AVGA2 Win 3.1 of another site dedicated to Tandy 1000 machines, but did not include the drivers for DOS/apps drivers.
The AVGA1 driver may work, but the main drawback of the AVGA1 drivers and card is it only supports 256kb of ram and the only SVGA resolution is 800x600 16-color. and some VESA text modes.
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ruben_balea
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Location: Spain

Re: [Bug] Commodore SL386SX-25 garbagge in the screen

Post by ruben_balea »

Hi,
That TSR seems to be some kind of loader and then a plain 32KB BIOS image with the correct checksum, if it works better I guess it could be extracted and used in place of the original ROM to save the base memory wasted by the TSR.

:arrow: Edit: That TSR contains a BIOS image without correct checksum and some garbage after it, I was thinking on another TSR :roll: Anyway I extracted it, truncated it to 32768 bytes and changed last byte to 0x04 to fix checksum and it worked as expected as PCem ROM but just like the TSR it seems to be incompatible with AVGA2 drivers for Windows 3.x maybe that BIOS works with Cirrus Logic drivers for 5402/5420.

There are also at least other AVGA BIOS image from a different card or mainboard with the same BIOS version as the SL386SX-25 but displaying a different date in POST message, it must be the build date because the only changes are the date and the checksum byte.
Due to time constraints after summer I couldn't test any new PCem build, until yesterday I wasn't aware of that model being supported too.
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SarahWalker
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Re: [Bug] Commodore SL386SX-25 garbagge in the screen

Post by SarahWalker »

VEMM.SYS is targeting the VL82C202 chipset, not the SCAMP.
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SarahWalker
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Re: [Bug] Commodore SL386SX-25 garbagge in the screen

Post by SarahWalker »

Paintbrush glitch fixed in rev 1489.
Fenix77
Posts: 80
Joined: Fri 01 Sep, 2017 11:59 am

Re: [Bug] Commodore SL386SX-25 garbagge in the screen

Post by Fenix77 »

Two years have passed since this thread was opened, however, I finally found the correct hardware EMS driver for the SCAMP chipset. The hardware EMS driver detects the chip, but finds errors on all EMS memory pages.
The UMB_DRVR software driver to create UMB memory crash after detecting the chip too.

(I uploaded the VLEMM.SYS driver only on a floppy disk image, because this is very hard to find on the web.)
Attachments
VLSI 82C311 EMS driver.zip
(16.8 KiB) Downloaded 139 times
PCEM scamp freeze.png
PCEM scamp freeze.png (28.37 KiB) Viewed 1879 times
PCEM SCAMP EMS error.png
PCEM SCAMP EMS error.png (115.12 KiB) Viewed 1879 times
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