1 Dec
2001
1 Dec
'01
8:06 p.m.
Anyone know what this is? It came from a 256K IBM XT, I thought at first it
was a video card, (it was in the first slot), but it's got eight banks of
nine 41256 ram DIPs on it. That sounds like a lot for a mono video card,
doesn't it? Combo card? it's got a looong double-row of pin sockets along
the bottom just above the ISA connector, and another single row up the whole
edge between the external connectors (male 9 pin & female 25 pin) and the
components. Maybe a daughter board? It's got one 6-position DIP switch at
the top right (^vvvv^) and 3 three-pin jumpers along the top near the rams,
(xx. xx. xx.) It's got a couple've big (1/8") holes on the board, lending
credence to the daughterboard theory. All the chips are labeled in an
intersting way-- u84 158 is --get this-- a 74LS158N. Don't ya wish
everything was made like this?
The computer it came out of looks pretty interesting, aside for a decade's
worth of grime on it. A whopping 256K ram on the motherboard, 2x internal
floppy, Adaptec HDD controller, external (!) ummm... 20? Meg drive in a case
that _looks_ like an IBM part, but it doesn't actually _say_ IBM anywhere on
it. Connects via IDC connectors on ribbon cable. Strange. Have to pop the
case to plug it in. I hate to think just how much this setup must've cost
new.
ja ne
Bob
1 Dec
1 Dec
8:25 p.m.
On Sat, 1 Dec 2001, Robert Schaefer wrote:
Anyone know what this is? It came from a 256K IBM XT,
I thought at first it
Just like the name implies.
It is a RAM card.
Yes, there are numerous daughter cards, and related models with
permanently installed options, including floppy controller, laser
printer controller, scanner (IX-12) controller, etc.
2 Dec
2 Dec
6:29 a.m.
----- Original Message -----
From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com>
To: <classiccmp(a)classiccmp.org>
Sent: Saturday, December 01, 2001 09:25 PM
Subject: Re: Tall Tree Systems`JRAM-3'
On Sat, 1 Dec 2001, Robert Schaefer wrote:
> Anyone know what this is? It came from a 256K IBM XT, I thought at
first it
Just like the name implies.
It is a RAM card.
That would make the card in slot three the video card. I thought the third
card was a combo IO card. It has a hayes 1200b modem in slot two.
Yes, there are numerous daughter cards, and related models with
permanently installed options, including floppy controller, laser
printer controller, scanner (IX-12) controller, etc.
Any idea where I can get docs ? I'd imangine it'll need a driver to use the
extra ram.
Bob
11:43 a.m.
On Sun, 2 Dec 2001, Robert Schaefer wrote:
That would make the card in slot three the video card.
I thought the third
card was a combo IO card. It has a hayes 1200b modem in slot two.
Slots don't matter much on the IBM PC/XT except for slot 8, which was
reserved for something (I can't remember exactly what right now.) Clone
PC/XT boards usually did not restrict slot 8. There could be more than one
I/O card in these old machines, since you could disable certain functions
on the cards, and use more then one in the same machine. Since there is a
modem in that machine, I would expect that there is only one enabled
serial port on any I/O cards.
Any idea where I can get docs ? I'd imangine
it'll need a driver to
use the extra ram.
Good luck on the docs, sometimes they can be had by talking to the board's
original manufacturer. Due to all the clones and cheap I/O cards that
appeared around that time, finding the company may not even be possible
now. If you know someone with an older MicroHouse cdrom, it might contain
docs that could help you. Sometimes even docs for a similar card can be
used, since there were many many clones and copies of boards.
You won't need a driver for most PC/XT ram cards, since they just expand
the base memory. If the I/O card has a real time clock, then you would
need a special program to read the clock at boot time.
-Toth
1:10 p.m.
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1:13 p.m.
On Sun, 2 Dec 2001, Tothwolf wrote:
> Any idea where I can get docs ? I'd imangine
it'll need a driver to
> use the extra ram.
You won't need a driver for most PC/XT ram cards,
since they just expand
the base memory. If the I/O card has a real time clock, then you would
need a special program to read the clock at boot time.
For THIS one, you WILL need a "driver". This is NOT "normal" memory,
it
is a predecessor to LIM EMS paged real mode expanded memory (up to 16? M
of RAM in a processor mode that can't comprehend more than 1M at a time!)
There is no RTC, except on daughter cards.
If you are NOT in a hurry, I can help. If you ARE in a hurry, then I'll
sell you the whole pile (2 totes), and you can try to sort it out.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
1:07 p.m.
On Sun, 2 Dec 2001, Robert Schaefer wrote:
While it certainly might be, I don't see how THIS makes it one.
It is a RAM
card.
That would make the card in slot three the video card. I thought the third
card was a combo IO card. It has a hayes 1200b modem in slot two. > Yes, there are numerous daughter cards, and
related models with
> permanently installed options, including floppy controller, laser
> printer controller, scanner (IX-12) controller, etc.
The only daughter card
that I DON'T remember being available would be one
for MORE memory.
Any idea where I can get docs ? I'd imangine
it'll need a driver to use the
extra ram.
Docs? , Drivers?
I'll be glad to, but it may be a while.
I have two totes full of them!, but they are on the bottom, back side of
the few hundred totes containing the residue of my office.
I know where ONE of the totes of them is, and can probably get to that one
soon. The other tote will happen when I get to it.
I did something real stupid when I moved out of my office. I tried to
organize the stuff that I was packing. For example, I put all of my
staplers (regular ones, binding ones, heavy duty ones, deep throat ones,
...) into one box. Now I can't find 'em, and have NO stapler.
OB_historical_pedantics: John Henderson? (Tall Tree Systems) approached
me (and others) at the West Coast Computer Faire, with a question of "have
you written any programs that use lots of memory?" We thought that he was
trying to recruit people with experience in memory management, etc. for a
project. He wasn't. He was coming out with MASSIVE memory boards, some
with MORE THAN A MEGABYTE! of memory for the PC. He wasn't looking for
project workers, he was looking for existing stuff that could comprise a
market and use for his product.
(That's what you have)
Eventually, he found the application for it. He marketed a laser printer
controller, that bypassed the 256K, text only, controller of the HP
LaserJet, etc, and created complete bitmap images in RAM (on his board) in
the PC, and dumped them straight into the printer engine.
(That was the JLASER board, with 2M of expanded RAM and laser printer
controller)
Later on, Lotus, Intel, and Microsoft met (and explicitly did NOT invite
Tall Tree, the primary provider of such boards!) and worked out the
"Lotus-Intel-Microsoft Expanded Memory Specification" ("LIM EMS").
It
took Tall Tree less than a month to make revisions to be compatible with
their "standard".
He also produced the very popular JFORMAT, which was a simple device
driver for squeezing 400K on a disk (10 512 byte sectors per track), as
well as doing 720K and 800k on 96TPI low density (Tandon TM100-4, etc.)
I have JLASER, JLASER-PLUS (with scanner interface), JRAM, JRAM2, JRAM3,
JDISK, ..., ..., It's not very organized, and I know where one tote of
them is, but not yet where the other one is. Who wants some?
--
Grumpy Ol' Fred cisin(a)xenosoft.com
2:05 p.m.
----- Original Message -----
From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, December 02, 2001 02:07 PM
Subject: Re: Tall Tree Systems`JRAM-3'
the
I'm in no rush, in fact no true need other than curiousity. I'm getting
curious about what's on the ST225 in the external case-- it came from the
same pile, judging by the dirt on it.
On Sun, 2 Dec 2001, Robert Schaefer wrote:
> > It is a RAM card.
> That would make the card in slot three the video card. I thought the
third
card was a
combo IO card. It has a hayes 1200b modem in slot two.
While it certainly might be, I don't see how THIS makes it one.
> Yes, there are numerous daughter cards, and
related models with
> permanently installed options, including floppy controller, laser
> printer controller, scanner (IX-12) controller, etc.
The only daughter card
that I DON'T remember being available would be one
for MORE memory.
> Any idea where I can get docs ? I'd imangine it'll need a driver to use
extra ram.
Docs? , Drivers?
I'll be glad to, but it may be a while.
I have two totes full of them!, but they are on the bottom, back side of
the few hundred totes containing the residue of my office.
I know where ONE of the totes of them is, and can probably get to that one
soon. The other tote will happen when I get to it.
I did something real stupid when I moved out of my office. I tried to
organize the stuff that I was packing. For example, I put all of my
staplers (regular ones, binding ones, heavy duty ones, deep throat ones,
...) into one box. Now I can't find 'em, and have NO stapler.
^_^
OB_historical_pedantics: John Henderson? (Tall Tree Systems) approached
me (and others) at the West Coast Computer Faire, with a question of "have
you written any programs that use lots of memory?" We thought that he was
trying to recruit people with experience in memory management, etc. for a
project. He wasn't. He was coming out with MASSIVE memory boards, some
with MORE THAN A MEGABYTE! of memory for the PC. He wasn't looking for
project workers, he was looking for existing stuff that could comprise a
market and use for his product.
(That's what you have)
Interesting. I guess this a real bit of history I have here.
Eventually, he found the application for it. He marketed a laser printer
controller, that bypassed the 256K, text only, controller of the HP
LaserJet, etc, and created complete bitmap images in RAM (on his board) in
the PC, and dumped them straight into the printer engine.
(That was the JLASER board, with 2M of expanded RAM and laser printer
controller)
Later on, Lotus, Intel, and Microsoft met (and explicitly did NOT invite
Tall Tree, the primary provider of such boards!) and worked out the
"Lotus-Intel-Microsoft Expanded Memory Specification" ("LIM EMS").
It
took Tall Tree less than a month to make revisions to be compatible with
their "standard".
He also produced the very popular JFORMAT, which was a simple device
driver for squeezing 400K on a disk (10 512 byte sectors per track), as
well as doing 720K and 800k on 96TPI low density (Tandon TM100-4, etc.)
I have JLASER, JLASER-PLUS (with scanner interface), JRAM, JRAM2, JRAM3,
JDISK, ..., ..., It's not very organized, and I know where one tote of
them is, but not yet where the other one is. Who wants some?
What's the difference 'tween the various JRAM boards? Max installable ram?
--
Grumpy Ol' Fred cisin(a)xenosoft.com
Bob
2:27 p.m.
On Sun, 2 Dec 2001, Robert Schaefer wrote:
I'm in no rush, in fact no true need other than
curiousity. I'm getting
curious about what's on the ST225 in the external case-- it came from the
same pile, judging by the dirt on it.
Be aware that XT hard disk controllers are NOT mutually
interchangeable! If it was formatted on an XT compatible hard disk
controller, then you will need THAT model of controller to read it! (Or a
LOT of sector and below level programming!)
On the ATs, they standardized the controllers (almost), and you can read a
drive formatted with a different brand of controller.
Interesting. I guess this a real bit of history I
have here.
What's the difference 'tween the various JRAM boards? Max installable ram?
Mostly just subsequent "improvements".
8 bit and 16 bit interface
with/without LIM EMS support?
3:35 p.m.
----- Original Message -----
From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, December 02, 2001 03:27 PM
Subject: Re: Tall Tree Systems`JRAM-3'
Ok. The PC has an Adaptec controller assy # 401406-00 with ROMs dated '85
FWIW. I'm pretty sure the drive came with this PC, but worst case I could
just reformat, right? No embedded servo tracks that requires a fancy
controller/different roms/different controller to write?
Bob
On Sun, 2 Dec 2001, Robert Schaefer wrote:
> I'm in no rush, in fact no true need other than curiousity. I'm getting
> curious about what's on the ST225 in the external case-- it came from
the
same pile,
judging by the dirt on it.
Be aware that XT hard disk controllers are NOT mutually
interchangeable! If it was formatted on an XT compatible hard disk
controller, then you will need THAT model of controller to read it! (Or a
LOT of sector and below level programming!)
On the ATs, they standardized the controllers (almost), and you can read a
drive formatted with a different brand of controller.
> Interesting. I guess this a real bit of history I have here.
> What's the difference 'tween the various JRAM boards? Max installable
ram?
Mostly just subsequent "improvements".
8 bit and 16 bit interface
with/without LIM EMS support?
This is most assuredly an 8 bit card. Other than that, IDK. Guess I'll
just have to wait and see. Oh, it's serial # 803181 too.
3:13 p.m.
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3:41 p.m.
On Sun, 2 Dec 2001, Tony Duell wrote:
That is entirely correct!
The Jlaser was the most widely sold board that provided that interface.
They also made a tiny board to go into a LaserJet that would switch it in
and out of the system under software control!
--
Grumpy Ol' Fred cisin(a)xenosoft.com
Eventually, he
found the application for it. He marketed a laser printer
controller, that bypassed the 256K, text only, controller of the HP
LaserJet, etc, and created complete bitmap images in RAM (on his board) in
the PC, and dumped them straight into the printer engine.
Sounds like it worked
with a Canon CX-VDO printer.
This is a Canon CX engine with no internal formatter (controller) board.
It still has the DC controller -- the little microcontroller board for the
mechanics, but the interface is very low level. Essentially you have :
1 Dec
1 Dec
11:46 p.m.
On Sat, 1 Dec 2001, Robert Schaefer wrote:
Anyone know what this is? It came from a 256K IBM XT,
I thought at
first it was a video card, (it was in the first slot), but it's got
eight banks of nine 41256 ram DIPs on it. That sounds like a lot for
a mono video card, doesn't it? Combo card? it's got a looong
double-row of pin sockets along the bottom just above the ISA
connector, and another single row up the whole edge between the
external connectors (male 9 pin & female 25 pin) and the components.
Maybe a daughter board? It's got one 6-position DIP switch at the top
right (^vvvv^) and 3 three-pin jumpers along the top near the rams,
(xx. xx. xx.) It's got a couple've big (1/8") holes on the board,
lending credence to the daughterboard theory. All the chips are
labeled in an intersting way-- u84 158 is --get this-- a 74LS158N.
Don't ya wish everything was made like this?
This sounds like a memory expansion+i/o card, with functions similar to
the well known AST Six Pak Plus board. Does this card also have a 26 pin
header somewhere for the second serial port? Does it have a battery for a
real time clock? Make sure you write down the board's current dip switch
settings if you decide to try changing anything...
-Toth
2 Dec
2 Dec
6:32 a.m.
----- Original Message -----
From: "Tothwolf" <tothwolf(a)concentric.net>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, December 02, 2001 12:46 AM
Subject: Re: Tall Tree Systems`JRAM-3'
On Sat, 1 Dec 2001, Robert Schaefer wrote:
> Anyone know what this is? It came from a 256K IBM XT, I thought at
<snip>
This sounds like a memory expansion+i/o card, with functions similar to
the well known AST Six Pak Plus board. Does this card also have a 26 pin
header somewhere for the second serial port? Does it have a battery for a
real time clock? Make sure you write down the board's current dip switch
settings if you decide to try changing anything...
No headers other than the long ones for a daughter card. With a daughter
card installed, it looks like it'll obstruct the next slot, so any extra
ports might attach there. No battery or Dallas RTCs either. And don't
worry-- I'm not changing any setting until _after_ I know what they do!
-Toth
Bob
11:46 a.m.
On Sun, 2 Dec 2001, Robert Schaefer wrote:
From: "Tothwolf"
<tothwolf(a)concentric.net>
I've never seen an I/O card that used an daughter board for the second
serial port, but I imagine there were companies who tried such a design.
-Toth
On Sat, 1 Dec 2001, Robert Schaefer wrote:
> Anyone know what this is? It came from a 256K IBM XT, I thought at
<snip>
This sounds like a memory expansion+i/o card, with functions similar to
the well known AST Six Pak Plus board. Does this card also have a 26 pin
header somewhere for the second serial port? Does it have a battery for a
real time clock? Make sure you write down the board's current dip switch
settings if you decide to try changing anything...
No headers other than the long ones for a daughter card. With a daughter
card installed, it looks like it'll obstruct the next slot, so any extra
ports might attach there. No battery or Dallas RTCs either. And don't
worry-- I'm not changing any setting until _after_ I know what they do!
12:42 p.m.
On Sat, 1 Dec 2001, Tothwolf wrote:
This sounds like a memory expansion+i/o card, with
functions similar to
the well known AST Six Pak Plus board. Does this card also have a 26 pin
header somewhere for the second serial port? Does it have a battery for a
real time clock? Make sure you write down the board's current dip switch
settings if you decide to try changing anything...
It is NOT a multifunction card.
It is a memory card.
The DB25 is NOT parallel, it is not serial.
On the Jlaser/Jlaser-Plus that use the same basic board design, the DB25
is CX laser controller (NOT Centronicsw parallel!), and the DE9 is for
Canon IX-12 scanner (NOT video, serial, etc.)
The card is ALL memory, with just a few "glue" chips. There is no
multi-function stuff on it.
The "daughter" cards, on the other hand, have all sorts of weird stuff.
Want to buy a few?
--
Grumpy Ol' Fred cisin(a)xenosoft.com
1:19 p.m.
----- Original Message -----
From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, December 02, 2001 01:42 PM
Subject: Re: Tall Tree Systems`JRAM-3'
It is NOT a multifunction card.
It is a memory card.
The DB25 is NOT parallel, it is not serial.
On the Jlaser/Jlaser-Plus that use the same basic board design, the DB25
is CX laser controller (NOT Centronicsw parallel!), and the DE9 is for
Canon IX-12 scanner (NOT video, serial, etc.)
Cool! Any chance you have some docs on it? I haven't plugged anything in
to it yet, altho I did power up the system a few times. Once made it as far
as `PARITY 1 ERROR', most times it just sat there with the cursor blinking.
I've been reseating all the chips. Got a little too smart tho-- I pulled
one out to jam it back in, it came out crooked and broke two pins off.
:( If I can't find a spare off another board, I'll see about soldering the
pins back on. BTW, the MB has a V20. Is that stock on an IBM-branded XT?
The card is ALL memory, with just a few "glue" chips. There is no
multi-function stuff on it.
The "daughter" cards, on the other hand, have all sorts of weird stuff.
What kind of weird stuff? Interesting-weird or strange-and-useles-weird?
Want to buy a few?
daughterboards or cards?
--
Grumpy Ol' Fred cisin(a)xenosoft.com
Bob
1:50 p.m.
On Sun, 2 Dec 2001, Robert Schaefer wrote:
Yes
Yes
I'll try tomorrow to see if the more accessible tote of them has
docs/software for the JRAM-3, and let you know.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
Cool! Any chance you have some docs on it?
Yes, but not today.
to it yet, altho I did power up the system a few
times. Once made it as far
as `PARITY 1 ERROR', most times it just sat there with the cursor blinking.
It is absolutely NOT needeed for bringing up the computer, so pull it out,
and keep it out until the computer boots and runs properly.
PARITY 1 ERROR is ususally memory problems on the motherboard.
I've been reseating all the chips. Got a little
too smart tho-- I pulled
one out to jam it back in, it came out crooked and broke two pins off.
:( If I can't find a spare off another board, I'll see about soldering the
pins back on.
It's very ordinary 64K(bit) DRAM. Shouldn't be a problem finding, and you
could always disable that row of 9, and use the rest.
If that was on the motherboard, it COULD be a 256K (simple mod on XT to
run 2 rows of 256 and 2 of 64 for 640K total).
On an EARLY 5150 PC, it could be a 16K.
BTW, the MB has a V20. Is that stock on an
IBM-branded XT?
No. But it was a common add-in. The V20 was a plugin compatible
replacement for the 8088. It added an 8080 (not Z80) mode that was handy
if you're heavily CP/M oriented, and provided an average throughput
improvement of about 7% over the 8088. Since the performance improvement
was a function of what instruction mix you use, it varied from -30%? to
+200%, and was often sold to suckers as a 200% speedup.
It also used less power, and was handy in systems running off of
batteries.
(NOTE: to use a V20 in a Gavilan required some board mods!)
The card is
ALL memory, with just a few "glue" chips. There is no
multi-function stuff on it.
The "daughter" cards, on the other hand, have all sorts of weird stuff.
What kind of weird stuff? Interesting-weird or strange-and-useles-weird? Want to buy a
few?
daughterboards or cards?
12:34 p.m.
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1:27 p.m.
On Sun, 2 Dec 2001, Tony Duell wrote:
THAT daughterboard I haven't seen.
8 rows of 9 41256s sounds like 2Mbytes of
parity-checked RAM. That's too
much for an 8088 to address directly. So this is probably some kind of
paged memory board, quite likely to be so called 'expanded memory'.
RIGHT!!
doesn't
it? Combo card? it's got a looong double-row of pin sockets along
the bottom just above the ISA connector, and another single row up the whole
edge between the external connectors (male 9 pin & female 25 pin) and the
components. Maybe a daughter board? It's got one 6-position DIP switch at
Myabe a daughterboard for more I/O. The 9 pin D plug sounds like a serial port. Is there a
UART chip (40 pin,
8250, 16450, 16550) on the board anywhere? What about 1488 and 1489 chips
(RS232 buffers).
No UART. No 1488. No 1489.
If those chips are not on the board, then maybe the
external connectors
just link to the row of sockets on the PCB near them, and you need the
daughterboard for any I/O functions.
RIGHT!!
Since you use CX laser controllers, perhaps you would like one/many ISA
ones??? daughter card for JRAM?, on board along with the RAM on JLASER.
The JLASER interface was supported by Xerox Ventura, Z-SOFT (PCPaint,
etc), and a lot of others.
There were also emulators for Postscript and for HP PCL that ran with
the JLASER.
3:15 p.m.
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3:44 p.m.
On Sun, 2 Dec 2001, Tony Duell wrote:
yes. There are few people who know about, much less use the CX
engines. (I have also used a Jlaser with SX in a LaserJet model 2).
Since few people even know about them, I figure that you'd be one of the
most likely to be able to come up with a use for one or more of them.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
I assume, therefore, that you could, in theory, add a
daughtboard that
did use the DE9 as a normal serial port and the DB25 as a parallel port.
Even though that board may not ever have existed....
yes
Since you use
CX laser controllers, perhaps you would like one/many ISA
ones??? daughter card for JRAM?, on board along with the RAM on JLASER.
Hmmm...
Is this directed at me?
1:45 p.m.
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk
To: <classiccmp(a)classiccmp.org
Sent: Sunday, December 02, 2001 01:34 PM
Subject: Re: Tall Tree Systems`JRAM-3'
> Anyone know what this is? It came from a 256K IBM XT, I thought at
first it
<snip
> If those chips are not on the board, then
maybe the external connectors
> just link to the row of sockets on the PCB near them, and you need the
> daughterboard for any I/O functions.
Yup, that's my current guess too.
the chip I broke is marked `D8284A' & `8404HKP" & with the AMD symbol.
Any
chance that is something non-essential that won't keep the board from
booting?
> -tony
Bob
> was a video card, (it was in the first slot), but
it's got eight banks
of
All the slots on a PC/XT are identical, apart from slot 8 (which has the
well-known 'pull B8 low on reads from this card' problem). There is no
reason to assume that the card is slot 1 is video. Nor is there any
reason to assume that a video card in a PC/XT is MDA (or CGA for that
matter). It could be almost anything.
Well, I made a few mistakes. I think it's a PC, not a PC/XT. Five 8 bit
slots, a DIN tape port on the back, fully populated with 4 banks of 9 4564.
It is a MCA video card, the `black and white/parallel' was a dead giveaway.
> nine 41256 ram DIPs on it. That sounds like a lot for a mono video
card,
8 rows of 9 41256s sounds like 2Mbytes of parity-checked RAM. That's too
much for an 8088 to address directly. So this is probably some kind of
paged memory board, quite likely to be so called 'expanded memory'.
That's a lot bigger than I expected! The board has only 74 series logic on
it, apart from the ram, so I guess all support for the ports on it are
contained on the daughtercard. A closer look indicates that all the readily
visible traces coming from the ports end up on the single-row header.
2:31 p.m.
On Sun, 2 Dec 2001, Robert Schaefer wrote:
RIGHT
Well, I made a few mistakes. I think it's a PC,
not a PC/XT. Five 8 bit
slots, a DIN tape port on the back, fully populated with 4 banks of 9 4564.
It is a MCA video card, the `black and white/parallel' was a dead giveaway.
^^^
CAREFUL! That would be an MDA (Monochrome Display Adapter), or more
accurately MDP (Monochrome Display & Printer). MCA is MicroChannel
Architecture (as used in PS/2), which it most definitely is NOT.
picky, picky, ...
That's a lot bigger than I expected! The board
has only 74 series logic on
it, apart from the ram, so I guess all support for the ports on it are
contained on the daughtercard. A closer look indicates that all the readily
visible traces coming from the ports end up on the single-row header.
RIGHT
If those chips
are not on the board, then maybe the external connectors
just link to the row of sockets on the PCB near them, and you need the
daughterboard for any I/O functions.
Yup, that's my current guess too.
3:35 p.m.
----- Original Message -----
From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, December 02, 2001 03:31 PM
Subject: Re: Tall Tree Systems`JRAM-3'
On Sun, 2 Dec 2001, Robert Schaefer wrote:
> Well, I made a few mistakes. I think it's a PC, not a PC/XT. Five 8
bit
> slots, a DIN tape port on the back, fully
populated with 4 banks of 9
4564.
> It is a MCA video card, the `black and
white/parallel' was a dead
giveaway.
^^^
CAREFUL! That would be an MDA (Monochrome Display Adapter), or more
accurately MDP (Monochrome Display & Printer). MCA is MicroChannel
Architecture (as used in PS/2), which it most definitely is NOT.
picky, picky, ...
You are absolutely right, and I even know better. I can only plead brain
fart.
Bob
3:18 p.m.
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4:11 p.m.
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, December 02, 2001 04:18 PM
Subject: Re: Tall Tree Systems`JRAM-3'
Well, I guess it should be pretty easy to strip from another board, then.
Knew I saved those clone boards for something!
> the chip I broke is marked `D8284A' &
`8404HKP" & with the AMD symbol.
Any
chance that is
something non-essential that won't keep the board from
booting?
Not a hope. It's the CPU (and other) clock generator chip. Without it,
you'll not have any clock signals anywhere
-tony
Bob
8427
days inactive
8428
days old
27 comments
4 participants
participants (4)
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ard＠p850ug1.demon.co.uk -
cisin＠xenosoft.com -
rschaefe＠gcfn.org -
tothwolf＠concentric.net