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What is this? Post Photos of Mystery Items Here (vintage computers only)

After shooting these, maybe its the perspective in the video that makes CRT rear look bigger, the front face difference could be some weird 80s screen saver that encroaches over entire front face like a diving mask. The central bezel is the DSM one, two side ones are from screen saver, and it is held in the monitor ridges?
 
Zare said:
some weird 80s screen saver that encroaches over entire front face like a diving mask.
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I think that you're describing an anti-glare filter. It doesn't save the screen from anything. It tries to compensate for reflection of ambient light off the front of the CRT glass into the eye of the viewer. Some discussion:
 
Yes thank you - the right term is anti glare filter.
I have directly translated the phrase from my native language so the meaning was lost - it means saving/protecting from screens as opposed to saving screens.

Anyhow this filter would have to be tailor made for the M19 monitor.

I haven't found this movie online. I'd like to know if there are more scenes/angles of the setup.
 
Hi everyone

Well this is just 1/2 a mystery board because it is clearly a 16 bit memory expansion card
I cannot find any information in the internet about this


It is marked "Megabit V3" but nothing popped up... not even the supposedly company name Megabit ....


If someone is familiar with this kind of cards
It has some knobs to set the memory amount and start address I think which is very interesting
Apart from that seems a very generic expansion cards for the 286XT and 286 computers


Thanx
 

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nunoalex said:
Hi everyone

Well this is just 1/2 a mystery board because it is clearly a 16 bit memory expansion card
I cannot find any information in the internet about this


It is marked "Megabit V3" but nothing popped up... not even the supposedly company name Megabit ....


If someone is familiar with this kind of cards
It has some knobs to set the memory amount and start address I think which is very interesting
Apart from that seems a very generic expansion cards for the 286XT and 286 computers


Thanx
Click to expand...
"Megabit" is terrible branding. Like naming a tire "PSI"...

It looks like a combo expanded/extended memory card. See here.
 
g4ugm said:
Is there an FCC I on the reverse? Often a guide to the real maker.
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Don't need too, its definitely DFI by the rotary switches. This one would most likely be one made around the time of the 386sx, hence the larger memory size DRam... I knew DFI moment I seen it due to those rotary switches and PCB color.

The item in the image is a vintage DFI MEGABIT (Revision 3) 16-bit ISA Memory Expansion Card. [1]
Manufactured by DFI (Diamond Flower Inc.), this legacy add-on board was popular during the late 1980s and early 1990s for upgrading the system memory (RAM) of IBM PC/AT, 286, and early 386 computers. [1, 2, 3]

Key Technical Features
  • Interface: It uses a 16-bit ISA (Industry Standard Architecture) gold edge connector to interface with vintage PC motherboards. [1, 2]
  • Onboard Memory: The left side features sockets populated with DRAM DIP chips. The chips shown are Goldstar (LG) GM71C256 variants, meaning each chip provides 256 Kilobits of storage. Grouped together, they form banks to provide Expanded Memory (EMS) or Extended Memory (XMS). [1]
  • Configuration Knobs / Dials: The distinct yellow rotary switches (dials) at the top of the card are used to manually configure the starting memory address and the amount of memory allocated, eliminating the need to set complex rows of jumpers manually. [1]
  • Onboard Components: It includes discrete logic chips (such as 74-series TTL logic) and resistor networks (the red vertical bars labeled RP) to handle bus timing and address decoding.
 
twolazy said:
Don't need too, its definitely DFI by the rotary switches. This one would most likely be one made around the time of the 386sx, hence the larger memory size DRam... I knew DFI moment I seen it due to those rotary switches and PCB color.

The item in the image is a vintage DFI MEGABIT (Revision 3) 16-bit ISA Memory Expansion Card. [1]
Manufactured by DFI (Diamond Flower Inc.), this legacy add-on board was popular during the late 1980s and early 1990s for upgrading the system memory (RAM) of IBM PC/AT, 286, and early 386 computers. [1, 2, 3]

Key Technical Features
  • Interface: It uses a 16-bit ISA (Industry Standard Architecture) gold edge connector to interface with vintage PC motherboards. [1, 2]
  • Onboard Memory: The left side features sockets populated with DRAM DIP chips. The chips shown are Goldstar (LG) GM71C256 variants, meaning each chip provides 256 Kilobits of storage. Grouped together, they form banks to provide Expanded Memory (EMS) or Extended Memory (XMS). [1]
  • Configuration Knobs / Dials: The distinct yellow rotary switches (dials) at the top of the card are used to manually configure the starting memory address and the amount of memory allocated, eliminating the need to set complex rows of jumpers manually. [1]
  • Onboard Components: It includes discrete logic chips (such as 74-series TTL logic) and resistor networks (the red vertical bars labeled RP) to handle bus timing and address decoding.
Click to expand...
I disagree. There is no record of DFI producing a memory expansion card named Megabit. Only MegaLITH, which is completely different. There is nothing distinct about a green PCB. What are the other DFI cards with rotary switches? Every DFI card I have seen has jumpers or switch blocks.
 
Plasma said:
I disagree. There is no record of DFI producing a memory expansion card named Megabit. Only MegaLITH, which is completely different. There is nothing distinct about a green PCB. What are the other DFI cards with rotary switches? Every DFI card I have seen has jumpers or switch blocks.
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I sit corrected. I would still be interested to know what other DFI cards have rotary switches.

dfi.png
 

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Plasma said:
I sit corrected. I would still be interested to know what other DFI cards have rotary switches.
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The MEMO 2000 XT also had rotary switches, as well as one with 30 pin simm slots that the name escapes me atm. I never seen another brand card with these yellow rotary switches otherwise. Believe rev2 of this card also had the same rotary switches, but its been years. Glad I was able to help. Seems year by year I forget more. I repaired so many different machines in the 90s when I worked in a PC repair shop.
 
twolazy said:
The MEMO 2000 XT also had rotary switches, as well as one with 30 pin simm slots that the name escapes me atm. I never seen another brand card with these yellow rotary switches otherwise. Believe rev2 of this card also had the same rotary switches, but its been years. Glad I was able to help. Seems year by year I forget more. I repaired so many different machines in the 90s when I worked in a PC repair shop.
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The MegaLITH Plus has SIMMs but uses switch blocks. I have a few of those cards. Maybe there was an earlier non-plus version.
 
Plasma said:
I sit corrected. I would still be interested to know what other DFI cards have rotary switches.

View attachment 1324938
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Gosh thank you so much for the help
I'm going to try to install the card with this drivers on a 286 machine with just 512mb to see what gives

And yes Megabit ... is like branding your cake "yum yum" good luck googling "yum yum cakes"

Thank you so much !
 
twolazy said:
The MEMO 2000 XT also had rotary switches, as well as one with 30 pin simm slots that the name escapes me atm. I never seen another brand card with these yellow rotary switches otherwise. Believe rev2 of this card also had the same rotary switches, but its been years. Glad I was able to help. Seems year by year I forget more. I repaired so many different machines in the 90s when I worked in a PC repair shop.
Click to expand...

Thank you for the help my friend !
I had no idea DFI was that ancient ... I thought they ere more of the socket 3 / socket 7 era

Looks like they were not very proud of their product to not print their name anywhere ... :(
 
nunoalex said:
It is marked "Megabit V3" but nothing popped up... not even the supposedly company name Megabit ....
Click to expand...
Well, it's Megabit REV3, not Megabit V3. Seems to not help much in googling, but still.
Is your goal to figure out how to use the card or in particular to figure out who made it?
The I/O port switch hints at it being able to do EMS in addition to XMS might be an issue since I would guess that you need to configure how much to allocate for EMS v.s. XMS.
Otherwise the two other switches seems to set the starting address freely at 128k intervals, so would be easy to test the XMS functionality in any 16-bit ISA computer that has less than 15-16M RAM on board (or one where you can designate a "hole" in the memory space, for 16-bit ISA cards).
Plasma said:
"Megabit" is terrible branding. Like naming a tire "PSI"...
Click to expand...
Reminds me of Bridge Communications Terminal Server. Nowadays you can find results for their CS100 and CS200 models, but 25+ years ago you could only find that some uni in USA had one, and the sysadmin were (as expected) not willing to send a copy of the files it needs to network boot, to some random stranger on the internet...
 
MiaM said:
Well, it's Megabit REV3, not Megabit V3. Seems to not help much in googling, but still.
Is your goal to figure out how to use the card or in particular to figure out who made it?
The I/O port switch hints at it being able to do EMS in addition to XMS might be an issue since I would guess that you need to configure how much to allocate for EMS v.s. XMS.
Otherwise the two other switches seems to set the starting address freely at 128k intervals, so would be easy to test the XMS functionality in any 16-bit ISA computer that has less than 15-16M RAM on board (or one where you can designate a "hole" in the memory space, for 16-bit ISA cards).

Reminds me of Bridge Communications Terminal Server. Nowadays you can find results for their CS100 and CS200 models, but 25+ years ago you could only find that some uni in USA had one, and the sysadmin were (as expected) not willing to send a copy of the files it needs to network boot, to some random stranger on the internet...
Click to expand...

Yeah my main goal is to be able to use it as it is intended

I have always been told that this kind of card needs the correct DOS drivers to be able to operate

But I already got some hints here in the comments and as soon as I have time I will test it ... maybe this weekend
 
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