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lutiana
April 2nd, 2017, 07:08 PM
I have 3 that I cannot ID or work out what type they are (Hercules, MDA or CGA). I tried googling the ICs and anything else I could find on the card with no luck. They all have a DB-25 female (assuming this is a parallel port) and a DB-9 female (which is why I think they are video cards).

Here are some pictures:

Card 1:

37528

Card 2:
37529

Card 3:
37530


And as always, thanks in advanced!

roberttx
April 2nd, 2017, 07:51 PM
I don't recall ever seeing a video/parallel port on the same card. That's not to say that it never happened, just I've never seen one.

Given the presence of a DB25 and a DE9, what leads you to believe that they're not I/O cards, with one parallel and one serial port? I'm pretty sure that I have several such cards, though it's too late to go look them out.

Also, what did you find when you looked at the datasheets for the ICs?

Xacalite
April 2nd, 2017, 07:53 PM
Card 1 - 16 MHz XTAL, can't read markings on RAM chips, but there's probably 64 KB, so Hercules
Card 2 - strange, 32 MHz XTAL, 64 KB RAM, no idea why did they use 32 MHz instead of 16, but it's most likely Hercules anyway, see here: http://www.vgamuseum.info/index.php/component/k2/item/387-sis-86c12 - similar chipset, also with 32-something XTAL
Card 3 - 16 MHz XTAL, 64 KB RAM, so Hercules

roberttx
April 2nd, 2017, 07:57 PM
Card 1 - 16 MHz XTAL, can't read markings on RAM chips, but there's probably 64 KB, so Hercules
Card 2 - strange, 32 MHz XTAL, 64 KB RAM, no idea why did they use 32 MHz instead of 16, but it's most likely Hercules anyway, see here: http://www.vgamuseum.info/index.php/component/k2/item/387-sis-86c12 - similar chipset, also with 32-something XTAL
Card 3 - 16 MHz XTAL, 64 KB RAM, so Hercules

Huh! I guess my memory is faulty.

lutiana
April 2nd, 2017, 07:58 PM
...what leads you to believe that they're not I/O cards, with one parallel and one serial port?

They have DB-9 FEMALE connectors, serial is always DB-9 male. So I am pretty sure that they are video cards, plus I have seen many CGA/MDA cards with parallel ports on them, I have several.

roberttx
April 2nd, 2017, 08:01 PM
They have DB-9 FEMALE connectors, serial is always DB-9 male. So I am pretty sure that they are video cards, plus I have seen many CGA/MDA cards with parallel ports on them, I have several.

Yeah, I failed to notice the female thing - my bad. Plus, see my earlier comment about faulty memory. Some of us are getting old, you know?

lutiana
April 2nd, 2017, 08:02 PM
Card 1 - 16 MHz XTAL, can't read markings on RAM chips, but there's probably 64 KB, so Hercules

Only two chips appear to be RAM, they are both MT 4067-12 chips. They are the ones with the flag on them.



Card 2 - strange, 32 MHz XTAL, 64 KB RAM, no idea why did they use 32 MHz instead of 16, but it's most likely Hercules anyway, see here: http://www.vgamuseum.info/index.php/component/k2/item/387-sis-86c12 - similar chipset, also with 32-something XTAL

Awesome, thanks on that.



Card 3 - 16 MHz XTAL, 64 KB RAM, so Hercules

Ok, thanks!

Xacalite
April 2nd, 2017, 08:07 PM
Only two chips appear to be RAM, they are both MT 4067-12 chips. They are the ones with the flag on them.
MT4067-12 - IC,DRAM,PAGE MODE,64KX4,MOS,DIP,18PIN,PLASTIC
So it's 64 KB total, ie. definitely Hercules, and not just MDA

lutiana
April 2nd, 2017, 08:13 PM
Great. Good to know.

Just curious, how would a CGA card differ? More RAM? Different crystal?

zombienerd
April 2nd, 2017, 08:30 PM
The 2nd card has a SiS 86C16, which is a HCGA chip.

http://www.datasheetarchive.co.uk/pdf/download.php?id=6f3325dc4da1cf0f473dad60f4911efd12 15e8&type=O&query=86C16

Xacalite
April 2nd, 2017, 08:32 PM
Just curious, how would a CGA card differ? More RAM? Different crystal?
CGA cards have 16 KB RAM and no crystal, they use 14.31818 MHz dot clock from the motherboard, via the OSC line on ISA bus.
There are also "dual" cards, ie. switchable between CGA and Hercules, they look like Hercules ones, but have some jumper/switch described "mono/color".

lutiana
April 2nd, 2017, 08:42 PM
CGA cards have 16 KB RAM and no crystal, they use 14.31818 MHz dot clock from the motherboard, via the OSC line on ISA bus.
There are also "dual" cards, ie. switchable between CGA and Hercules, they look like Hercules ones, but have some jumper/switch described "mono/color".

Makes sense, and EGA would have way more than 64kb of RAM and/or a different crystal? Or would the only diff there be the lack of a parallel port?

krebizfan
April 2nd, 2017, 09:06 PM
Makes sense, and EGA would have way more than 64kb of RAM and/or a different crystal? Or would the only diff there be the lack of a parallel port?

IBM's EGA card only had 64kB of RAM and needed a daughter card to reach the 256kB level. Most clone EGA cards had 256kB installed.

IBM EGA card has its own crystal.

IBM EGA lacks parallel port but instead has 2 RCA connectors and a switch block exposed to the back. Adjacent to the RCA connectors would be the feature connector.

Xacalite
April 2nd, 2017, 09:16 PM
Makes sense, and EGA would have way more than 64kb of RAM and/or a different crystal? Or would the only diff there be the lack of a parallel port?
Genuine IBM EGA can have from 64 to 256 KB RAM, and 16.257 MHz XTAL.
Clone cards usually already come with full 256 KB, and can have additional crystal(s) to support higher resolutions.
In general, it's easy to identify EGA-class cards by DIP-switches on the bracket (to select the monitor type), two RCA connectors, and internal 32-pin feature connector: http://minuszerodegrees.net/5170/cards/ibm_ega.jpg

BTW, that SIS 86C16 card of yours is actually one of those Hercules/CGA duals, now you just need to find the docs on jumper/dipswitch settings...

lutiana
April 2nd, 2017, 09:50 PM
BTW, that SIS 86C16 card of yours is actually one of those Hercules/CGA duals, now you just need to find the docs on jumper/dipswitch settings...

I think that finding those settings is unlikely given that I could not even work out it was Hercules from the info on the board.

Xacalite
April 3rd, 2017, 02:50 AM
I can only find datasheet for the chipset, not for the whole card.
You can look at the opposite side, perhaps there's some FCC ID there, which would allow to identify the manufacturer, but even then the chances of finding the docs are low.
Probably the only hope is trial-and-error, J2 is obviously light-pen connector, so there are only two jumpers and four switches.
23C07 is EPROM, that jumper next to it must be somehow related, probably selects EPROM type.
The remaining must control Hercules/CGA mode, printer port address, and "Auto S/W Function".
It's best to experiment using a monitor which supports both Hercules and CGA timings, back in the era there was plenty of cheap noname monochrome monitors like that.
Just avoid experimenting with IBM 5151, as incorrect timings can damage it.