zb10948 wrote on 2024-03-30, 16:30:

Certainly Olivetti had a 8bit ISA with PVGA1A chip, so I guess it's possible.

Sure, there was plenty of PVGA1A cards for 8-bit ISA.

Also if anyone is running these PVGA1As in 8bit mode, what is the performance compared to something a bit later like TVGA8900D, similar or significantly below?

TVGA8900D is late ISA chipset, hitting the limit of the ISA bus.
PVGA1A is one of the earliest VGA clones, slow even on 16-bit bus, leave alone 8-bit.

+1

I have a few PVGA1As in 8-Bit form and to what I remember,
they all performed nicely in comparison to the ATI VGA Wonder I had in my 286-12 once.

That "card" (was an on-board VGA) was obviously using 8-Bit i/o and it showed.

Personally, I'd make sure to always load the RAM BIOS utility for your old ISA VGAs.
If shadow memory is being supported (video and system BIOS shadowing), then even better.

Because, VGA BIOS calls otherwise have to be made over the PC bus (ISA bus).

That's were the VGA's physical ROMs/EPROMs are being located, after all.

And using the BIOS routines in ROM/EPROM does take some time.

Edit: I've read the link and don't like the conclusion, it's too biased.

A PVGA1A should be allowed to have full 512KB, simply in order to be functional, like other SVGA cards.

Otherwise, a PVGA can do merely two SVGA modes: 800x600 16c and 640x400 256c.
The Windows 2.x and 3.x drivers support these modes natively, other programs require the VBE TSR.

The GO481 can have 512KB of video RAM, also, by stacking RAM chips (piggy-back method).
If done carefully, it can look like a factory mod.

But who're I'm telling this.. The emulator people seem to obsessed with paper specs, rather than real world usage. *sigh* 😔

Many people back in the 80s did some modifications to their hardware, or have it done by someone else (friend, company, local computer shop etc).

I wasn't really paying attention to optimization via shadowing as I'm evaluating the base line and whether they actually work for me.
The system is Olivetti but customized. It was never envisioned to be decoupled from onboard CGA nor there is any space for a 8 bit VGA in it. I had to mess with PALs to remove the embedded Colorplus-type CGA adapter from the bus and ofcourse I took steps to take care of the form factor availability. But some autosense cards like TVGA9000 don't work, while 8900D does.

I don't care what the poster on the PCem link thinks about 'things' or what PCem assumes to be the truth. Just wanted to verify that P1 and P2 are 16 bit bus/ROM selection so if they're not broken out for jumper removal, one needs to sever the connection manually at these points to select 8 bit mode.

So there's at least something factual to hang on, because if the comp doesn't boot, I won't know if card isn't actually in 8 bit or if my system is refusing to cooperate with it.

Jo22 wrote on 2024-03-30, 17:54:

Personally, I'd make sure to always load the RAM BIOS utility for your old ISA VGAs.
If shadow memory is being supported (video and system BIOS shadowing), then even better.

I can't find such utility for PVGA, I can for Trident.
Ofc my BIOS doesn't have shadowing. XT machine, no setup, no CMOS, no battery 😀

Jo22 wrote on 2024-03-30, 17:54:

Edit: I've read the link and don't like the conclusion, it's too biased. […]
Show full quote

Edit: I've read the link and don't like the conclusion, it's too biased.

A PVGA1A should be allowed to have full 512KB, simply in order to be functional, like other SVGA cards.

Otherwise, a PVGA can do merely two SVGA modes: 800x600 16c and 640x400 256c.
The Windows 2.x and 3.x drivers support these modes natively, other programs require the VBE TSR.

The GO481 can have 512KB of video RAM, also, by stacking RAM chips (piggy-back method).
If done carefully, it can look like a factory mod.

But who're I'm telling this.. The emulator people seem to obsessed with paper specs, rather than real world usage. *sigh* 😔

Many people back in the 80s did some modifications to their hardware, or have it done by someone else (friend, company, local computer shop etc).

I also don't understand why some decisions there, but it's their project so let them be.
What's questionable for me is asking for support of card but not uploading the GO481 BIOS saying go get a generic PVGA one, because an owner of the card can dump it himself and use on PCem. Why the gatekeeping of one VGA BIOS file?

zb10948 wrote on 2024-03-30, 21:33:

I can't find such utility for PVGA, I can for Trident.
Ofc my BIOS doesn't have shadowing. XT machine, no setup, no CMOS, no battery 😀

Hi, I think that's because the utility is found under WD/WDC category (Western Digital).

Western Digital was the mother company of Paradise and continued to sell the PVGA1A as WD90C00.

The Windows 2.x drivers do work with later WDs, still, btw.
Up to WD90C31 or something. I tried on a laptop once.

Here are some VBE drivers to try:
Re: OAK OTI-037c - 800x600 mode ?

Good luck! 😃

PS: There's Univesa and UniVBE, too, technically.
But my experience wasn't that great so far. Many programs crashed with UniVBE for some reasons.

zb10948 wrote on 2024-03-30, 21:33:

I also don't understand why some decisions there, but it's their project so let them be.
What's questionable for me is asking for support of card but not uploading the GO481 BIOS saying go get a generic PVGA one, because an owner of the card can dump it himself and use on PCem. Why the gatekeeping of one VGA BIOS file?

Me neither, I guess the GO481 is some sort of rare collectors item or something?
I only know the GO481 because of PCem, to be honest, were the 256KB limit is a bit annoying.

The only thing special about the GO481 might be compatibility with Olivetti video mode, but that's not a hardware feature.

It's rather a combination of GO481 VGA BIOS and the Olivetti BIOS.
It passes Olivetti specific video modes to the software routines of the Olivetti BIOS.
Any other PVGA hardware should be capable of same thing, if run on GO481 BIOS.

Jo22 wrote on 2024-03-30, 22:35:

Hi, I think that's because the utility is found under WD/WDC category (Western Digital).

Good luck! 😃

😀 Thanks I'll try in that direction

Jo22 wrote on 2024-03-30, 22:35:

Me neither, I guess the GO481 is some sort of rare collectors item or something? I only know the GO481 because of PCem, to be h […]
Show full quote

Me neither, I guess the GO481 is some sort of rare collectors item or something?
I only know the GO481 because of PCem, to be honest, were the 256KB limit is a bit annoying.

The only thing special about the GO481 might be compatibility with Olivetti video mode, but that's not a hardware feature.

It's rather a combination of GO481 VGA BIOS and the Olivetti BIOS.
It passes Olivetti specific video modes to the software routines of the Olivetti BIOS.
Any other PVGA hardware should be capable of same thing, if run on GO481 BIOS.

It's not rare and pricey just not common. In any case I'm dumping the bios and putting it on archive.org.

Olivetti XT machines with "special Olivetti modes" had custom monitors tied to the system, M24, M19, ETV series and so on, with their own sync rate. So Olivetti had to realize a custom CGA compatible card and the modes correspond to Plantronics Colorplus. M24 card is a proprietary 16bit adapter containing MC6845 with twice the RAM, so you can assign 2 bits in hi-res mode and get 4 colours - the Olivetti 640x400x4 mode. In M19 the graphics is ran by something which resembles a non LSI PVC4, meaning separate PVC2 and M6845 chips, presumably because PVC2 can run with faster memory chips needing less of them on a small form factor PC to get the same 32k.

Once Olivetti ditched proprietary CGA+ things and custom RGB monitors I believe they ran on VGA standard stuff. I have a leakage-broken M250 with PVGA1 onboard, there is no mention whatsoever about anything special.

So I'm highly curious what could be special about this card. Indeed it has Olivetti socketable array logic chips - same are found on M19's OGC.

zb10948 wrote on 2024-03-30, 23:58:

:) Thanks I'll try in that direction […]
Show full quote

Jo22 wrote on 2024-03-30, 22:35:

Hi, I think that's because the utility is found under WD/WDC category (Western Digital).

Good luck! 😃

😀 Thanks I'll try in that direction

Jo22 wrote on 2024-03-30, 22:35:

Me neither, I guess the GO481 is some sort of rare collectors item or something? I only know the GO481 because of PCem, to be h […]
Show full quote

Me neither, I guess the GO481 is some sort of rare collectors item or something?
I only know the GO481 because of PCem, to be honest, were the 256KB limit is a bit annoying.

The only thing special about the GO481 might be compatibility with Olivetti video mode, but that's not a hardware feature.

It's rather a combination of GO481 VGA BIOS and the Olivetti BIOS.
It passes Olivetti specific video modes to the software routines of the Olivetti BIOS.
Any other PVGA hardware should be capable of same thing, if run on GO481 BIOS.

It's not rare and pricey just not common. In any case I'm dumping the bios and putting it on archive.org.

Olivetti XT machines with "special Olivetti modes" had custom monitors tied to the system, M24, M19, ETV series and so on, with their own sync rate. So Olivetti had to realize a custom CGA compatible card and the modes correspond to Plantronics Colorplus. M24 card is a proprietary 16bit adapter containing MC6845 with twice the RAM, so you can assign 2 bits in hi-res mode and get 4 colours - the Olivetti 640x400x4 mode. In M19 the graphics is ran by something which resembles a non LSI PVC4, meaning separate PVC2 and M6845 chips, presumably because PVC2 can run with faster memory chips needing less of them on a small form factor PC to get the same 32k.

Once Olivetti ditched proprietary CGA+ things and custom RGB monitors I believe they ran on VGA standard stuff. I have a leakage-broken M250 with PVGA1 onboard, there is no mention whatsoever about anything special.

So I'm highly curious what could be special about this card. Indeed it has Olivetti socketable array logic chips - same are found on M19's OGC.

Whoa, thanks a lot for the information! 😁

Not sure if it's helpful, but I've dug out the original driver software for the generic PVGA1A..

Re: 286 USIT Athena PC

Jo22 wrote on 2024-03-31, 02:04:

Not sure if it's helpful, but I've dug out the original driver software for the generic PVGA1A..

Re: 286 USIT Athena PC

Thanks, will try with this.

Olivetti built their own in early 80s, these are GO317/318 and GO380, built for M24 and related M21 and M28.

I think Olivetti picked up Paradise back then as a chip vendor to minimize the cost of development of a bunch of adapters they needed to have to support a bunch of standards active in the mid to late 80s, because the above were built around CGA CRTC only. PVC2/4 support Hercules, CGA, Plantronics, etc.

In late 80s they had an extra half dozen GO's available for EGA, VGA, and PGC for their standard AT 286 systems. I'm not sure about PGC but EGA and VGA were ran by Paradise, and platforms having onboard graphics also had Paradise. One of their last 286s to be built had a Matrox onboard option beside Paradise. I believe this is the last Paradise-Olivetti system, as further 386,486 and Pentiums used regular SVGA chips from SiS, Cirrus Logic, Trident, Matrox, ATi, from what I've seen personally, there are probably S3 systems, and so on.

So after 386 Olivetti just has a bog standard VGA.

About this GO481 comparing the bios dump to standard PVGA could tell us something, but I think they're mystifying it due to rareness of original Olivetti expansion cards. Some of these had to perform a secondary electric or signalling usage for a custom 16-bit bus, some conformed to form factors available only in Olivetti boxes. For example M19 has a bunch of original cards made for it, SCSI controller, modem, some arhaic LAN card, usual stuff. These are extremely rare. Each of these is worth about the same as the entire machine. But this PVGA? Nah. They are available on ebay for fair price. I got mine for 40 euro on ebay a month ago. Any of the original cards for non-AT Olivetties is worth minimally 5 times more.

Well I just wanted to drop in Oli VGA instead of Trident so everything is kinda 'original' and in same era (M19 is '86 card is '88), looks like there's further investigation to do. The fun with Olivetti never stops.
I really don't know why put logic chips in there, 286 PVGA onboard is a straight solution, there is no 'custom BIOS stuff', and you can insert any 16bit ISA VGA in said 286 machines by setting a jumper on board like you would on any other computer.

https://archive.org/details/go-481

Can't get correct video signal out, I'm getting diagonal stripe pattern on screen, the traces are cut and verified no connection, the machine POSTs normally.