Vipersan
Emmett Browns Ghost
- Joined
- Jun 29, 2009
- Messages
- 10,918
- Reaction score
- 6,663
- Points
- 113
- Age
- 66
- My Satellite Setup
-
IP9000HD +
TD110 Dish and TD88 Dish in Tandem
66°East to 60°West.
AZbox PrmHD + OpnbxS9HD + Skybox + DrHD F15
2x VboxII AZ-EL
2 m+ Alcoa PF + BSC421 C-Band lnbf...
+SS2/TwHnS2-3200 pci/TBS6925 pci
1.5 Fortec Star -Gbox - HtoH Ku/Ka/C
- My Location
- UK
As promised I'm starting this thread to illustrate the rather complex process of making a T5200 work with Win95 ..
yes ..you read that right.
This ancient lump of retro tech circa 1991 was released with a standard paltry 2mb of plug in memory and a few k of internal ram soldered to a plug in board.
Memory was a seriously expensive commodity back then ..and a fully upgraded 12mb machine could easily double the purchase price ..which was several grand for the basic machine.
It came as standard with a 60 or 100 mb ..not gb conner hard drive ..which had oil filled bearings.
over time these bearings released the oil which destroyed the hard drive surface ..so to have a worker is indeed a rarity..
I have such a rarity ..but for how much longer ?
To that end ..and to have more storage space I needed to fit a larger hard drive.
That was the first major problem..
The Bios only accepted Conner drives ..and nothing else.
I made friends with a smart guy called Ian ..who was able to hack ..reverse engineer ..and patch the bios to accept other hard drives ..
This of course required the modified bios be flashed to a replacement 1024 UV eraseable eprom.
so now I could run DOS or win3.1 on a HD of my choosing.
Problem was I still needed more memory/ram.
Toshiba used 40 pin proprietory simms which were expensive in their day ..but rare as rocking horse scat.
Ian had an idea that 72 pin EDO memory could be hand wired to the 40 pin slot connections ..using the original 2k of ram as parity ..
This too had limitations ..but at least 12mb was now a reality.
Ok
RAM sorted but still the unit could only run Win3.1 ...
Could it do Win95 ???
certainly it was never intended to..
afterall it pre-dated win95 by a few years..
well ..maybe ..
but in order to do this a faster CPU was needed ..
the original was a 386 ...BUT...a pin compatible 486 was made ..
and also a method of cache flushing was needed.
This was achieved with a small submounted 7400 nand logic chip ..and wired to the relevant points on the cpu etc.
Now it might be possible to install Win95.
BUT ..since the floppy drive was the only way to get data in and out ...a 22 floppy disk installation for win 95 was created.
but ..Oh dear the floppy disk drive no longer functioned ..and again ..was proprietory ..
A standard floppy drive might be used but was wired totally diferently.
A custom cable with the correct IDC connections had to be made up ..
..and a sigh of relief when the disks were recognised.
Now I could install my chosed OS.
The plasma screen dictates the colour depth and aspect ratio of the VGA output ..
So ..no SVGA or larger ..
max 640:480..
but progress nonetheless...and gass plasma screen and mirrored to an external monitor ..
in colour but at a paltry 256 colour depth.
This I fear is the limit..but still.
What about sound ??
Well there is the internal speaker ..but an ISA soundblaster would be nice.
The T5200 comes with 2 x ISA sockets as standard ..but sadly only one of these was 16 bit ..
The other is a short 8 bit socket...and I wanted not only sound but also network and a CD rom drive..
Well this is 1995 ..lol
How could this be done ?
Well ..I had a flash of inspiration ..
I could fit a 16 bit ISA card which supports PCMCIA ...but I wanted sound as well ..and I only have one 16 bit ISA socket.
Grrr ..
but what if I added a second 16 bit socket ?
I set about converting the 8 bit socket into a 16 bit socket ..
I manufactured an edge mounted riser card of which half the contacts could plug into the 8 bit socket ..and the remaining 36 connections hanging in the air could be hand wired in parallel to the 16 bit socket..
et voila ..
I now had 2x 16 bit ISAs ..one of which _could_ host a thin ..short ..pcmcia card ..which in turn could be connected to a dual pcmcia socket unit ...leaving the 'real' 16 bit socket for a sound card ..
The PCMCIA would support both a network card ..and a CD drive inerface card..
For the moment ..this is where I am at..
I'm attaching a general photo of the main pcb with the EDO hand wired ram in place ...the 486 fitted ..and the cache flush on the underside ..
other pics will follow with details if needed..
rgds
VS
yes ..you read that right.
This ancient lump of retro tech circa 1991 was released with a standard paltry 2mb of plug in memory and a few k of internal ram soldered to a plug in board.
Memory was a seriously expensive commodity back then ..and a fully upgraded 12mb machine could easily double the purchase price ..which was several grand for the basic machine.
It came as standard with a 60 or 100 mb ..not gb conner hard drive ..which had oil filled bearings.
over time these bearings released the oil which destroyed the hard drive surface ..so to have a worker is indeed a rarity..
I have such a rarity ..but for how much longer ?
To that end ..and to have more storage space I needed to fit a larger hard drive.
That was the first major problem..
The Bios only accepted Conner drives ..and nothing else.
I made friends with a smart guy called Ian ..who was able to hack ..reverse engineer ..and patch the bios to accept other hard drives ..
This of course required the modified bios be flashed to a replacement 1024 UV eraseable eprom.
so now I could run DOS or win3.1 on a HD of my choosing.
Problem was I still needed more memory/ram.
Toshiba used 40 pin proprietory simms which were expensive in their day ..but rare as rocking horse scat.
Ian had an idea that 72 pin EDO memory could be hand wired to the 40 pin slot connections ..using the original 2k of ram as parity ..
This too had limitations ..but at least 12mb was now a reality.
Ok
RAM sorted but still the unit could only run Win3.1 ...
Could it do Win95 ???
certainly it was never intended to..
afterall it pre-dated win95 by a few years..
well ..maybe ..
but in order to do this a faster CPU was needed ..
the original was a 386 ...BUT...a pin compatible 486 was made ..
and also a method of cache flushing was needed.
This was achieved with a small submounted 7400 nand logic chip ..and wired to the relevant points on the cpu etc.
Now it might be possible to install Win95.
BUT ..since the floppy drive was the only way to get data in and out ...a 22 floppy disk installation for win 95 was created.
but ..Oh dear the floppy disk drive no longer functioned ..and again ..was proprietory ..
A standard floppy drive might be used but was wired totally diferently.
A custom cable with the correct IDC connections had to be made up ..
..and a sigh of relief when the disks were recognised.
Now I could install my chosed OS.
The plasma screen dictates the colour depth and aspect ratio of the VGA output ..
So ..no SVGA or larger ..
max 640:480..
but progress nonetheless...and gass plasma screen and mirrored to an external monitor ..
in colour but at a paltry 256 colour depth.
This I fear is the limit..but still.
What about sound ??
Well there is the internal speaker ..but an ISA soundblaster would be nice.
The T5200 comes with 2 x ISA sockets as standard ..but sadly only one of these was 16 bit ..
The other is a short 8 bit socket...and I wanted not only sound but also network and a CD rom drive..
Well this is 1995 ..lol
How could this be done ?
Well ..I had a flash of inspiration ..
I could fit a 16 bit ISA card which supports PCMCIA ...but I wanted sound as well ..and I only have one 16 bit ISA socket.
Grrr ..
but what if I added a second 16 bit socket ?
I set about converting the 8 bit socket into a 16 bit socket ..
I manufactured an edge mounted riser card of which half the contacts could plug into the 8 bit socket ..and the remaining 36 connections hanging in the air could be hand wired in parallel to the 16 bit socket..
et voila ..
I now had 2x 16 bit ISAs ..one of which _could_ host a thin ..short ..pcmcia card ..which in turn could be connected to a dual pcmcia socket unit ...leaving the 'real' 16 bit socket for a sound card ..
The PCMCIA would support both a network card ..and a CD drive inerface card..
For the moment ..this is where I am at..
I'm attaching a general photo of the main pcb with the EDO hand wired ram in place ...the 486 fitted ..and the cache flush on the underside ..
other pics will follow with details if needed..
rgds
VS
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