benz@CS.BUFFALO.EDU (David Benz) (01/22/88)
I have an "old" z100 still running at 5Mhz, with the full
complement of 192K RAM. I'm feeling a bit cramped with
this and would like to add more memory. The cheapest and
simplest method seems to be the upgrade sold by FBE, does
anybody have any comments about this product? Do I have to
modify my computer in any other ways, does it mess up any
programs, etc... Also, how about the merits of just sliding
a card into the s100 cage? Are their any around that don't
cost an arm and a leg, is it as simple as just sliding it
in and booting, etc.. Finally, is it possible to do both?
If I go with the FBE upgrade I'll have all those 64K chips
sitting around collecting dust, or maybe the cat could play
with them. :-)
Thanks for your help
Dave Benz SUNY at Buffalo CS Dept.
internet:benz@cs.buffalo.edu bitnet: benz@sunybcs.BITNET
csnet: benz@buffalo.csnet
uucp: ..!{ames,boulder,decvax,rutgers}!sunybcs!benzklee@klee.ads.com (Ken Lee) (01/22/88)
In article <8801211903.AA02813@bellatrix.cs.buffalo.edu.cs.buffalo.edu> benz@CS.BUFFALO.EDU (David Benz) writes: >I have an "old" z100 still running at 5Mhz, with the full >complement of 192K RAM. I'm feeling a bit cramped with >this and would like to add more memory. The cheapest and >simplest method seems to be the upgrade sold by FBE, does >anybody have any comments about this product? I installed the FBE kit in my "old motherboard" H110 a couple of years ago. It works fine with all my software (admittedly not much) at both 5MHz and 7.5MHz. I mainly use the extra memory as a RAM drive, which is faster than any hard disk I've seen. Ken
bh0r@CLUTX.CLARKSON.EDU (Rob Logan) (01/22/88)
I wrote this TeX file for a class last year. It will is the patch
to put 768K on an old Z100.
--------------------------------------------------------------------
% History:61
\documentstyle [12pt] {report}
\begin {document}
\begin {titlepage}
\title {Adding 256k chips to\\
your older Z--100.}
\author {Robert Logan \\
Paper 6 \\
TC 210--01}
%\date {\today}
\end {titlepage}
\maketitle
%\baselineskip 24 pt
\vspace {1 in}
\centerline {\Large \em Audience Analysis}
\vspace {2 in}
This modification is not intended for a beginner. It assumes you have a strong
electrical background. Experience building pc boards is necessary.
\newpage
\vspace {.25 in}
\centerline {\Large \bf Adding 256k chips to your older Z--100.}
\vspace {.25 in}
\centerline {\Large \em Before we begin.}
\vspace {.25 in}
Before we get started you need to collect the following:
\begin {centering}
\begin {description}
\item [1] 16 pin socket.
\item [1] 20 pin socket.
\item [1] 33 ohm resistor.
\item [1] 74LS257
\item [9, 18 or 27] 41256 RAM chips.
\item [5'] 26ga wire.
\item [1] soldering iron.
\item [1] 181--4918 or earlier Z--100. {\sf Note: Computers with a
later model number (found near the parallel port) just new PALs.}
\item [1] 1' solder. {\em Caution: Do not use acid core solder.}
\item [1] Large work bench.
\item [1] 1 hour of time.
\end {description}
\end {centering}
For you absent minded hacks that forgot pins of a chip are numbered starting
from the upper left hand corner counting counter clock wise around the chip,
here is a table:
\newpage
\vspace {.25 in}
\centerline {\Large \em Getting things ready.}
\vspace {.25 in}
\begin {description}
\item [( )]
Disassemble your computer following the instructions provided in your Z--100 Users
Manual pages 3--10.
\item [( )]
Remove the main board totally from the computer case by removing the 10 screws
and the card cage.
\item [( )]
Place the board a large work bench.
{\sf Tip: Put a dry towel on your table under the board so it does not slip.}
\item [( )]
Identify U111, U146 and U173, these are the chips we will be working with.
\newpage
\item [( )]
Remove U101 through U109 (bottom 64k of RAM)
\item [( )]
Remove U117 through U125 (middle 64k of RAM)
\item [( )]
Remove U137 through U145 ( top 64k of RAM)
\item [( )] Flip the board over and identify pin 1 of the all the RAMs U101
through U109, U117 through U125 and U137 through U145. {\em Caution: remember
the pins are reversed if you are looking from the bottom.}
\item [( )]
Solder a continuous wire to all RAM pin 1's
\item [( )]
Leave about 5" of wire and flip the board over, chips side up.
\item [( )]
Install U101 through U109 with new 41256s (bottom 256k of RAM).
\item [( )] Install U117 through U125 (if you have them) with new 41256s
(middle 256k of RAM).
\item [( )] Install U137 through U145 (if you have them) with new 41256s
(top 256k of RAM).
\vspace {.25 in}
\centerline {\Large \em The U146 modification.}
\vspace {.25 in}
\item [( )]
Take your 74LS257 and cut off pins 5, 6, 7, 9, 10, 11, 12, 13 and 14.
\item [( )]
Bend out vertically pins 2, 3, 4 and 15.
\item [( )]
Verify that pins 1, 8 and 16 are the only pins left sticking down.
\item [( )]
Solder a wire from pin 15 to pin 8.
\item [( )]
Solder a 5'' wire pin 3.
\item [( )]
Solder a 5'' wire pin 2.
\item [( )]
Solder one end of the 33 ohm resister to pin 4.
\item [( )]
Solder the wire from the RAM's pin 1 to the other end of the 33 ohm resister.
\item [( )]
Pull the 74LS257 at U146 and solder the new 74LS257 to
the top of it with pins 1, 8 and 16.
\item [( )]
Inspect the new piggy backed chip for shorts and reinsert it into U146.
\vspace {.25 in}
\centerline {\Large \em The U173 modification.}
\vspace {.25 in}
\item [( )]
Pull the PAL at U173.
\item [( )]
Bend up pins 1 and 2.
\item [( )]
Solder a jumper from 1 and 2 to pin 10.
\item [( )]
Take your 20 pin socket and solder a 5'' wire into the hole were pin 1 would
have gone.
\item [( )]
solder another 5'' wire into the hole were pin 2 would have gone.
\item [( )]
Install the PAL into your new socket.
\item [( )]
Inspect the new socket/chip pair for shorts.
\item [( )]
Install the new socket/chip pair back in to U173.
\vspace {.25 in}
\centerline {\Large \em The U111 modification.}
\vspace {.25 in}
\item [( )]
Remove the Memdec chip at U111.
\item [( )]
Bend up pins 2 and 3
\item [( )]
Solder the wire from the socket pin 1 of U172 to pin 3 of U111.
\item [( )]
Solder the wire from the socket pin 2 of U172 to pin 2 of U111.
\item [( )]
Solder the wire from the top 74LS257 of U146 pin 2 to the 3 hole
of the 16 pin socket.
\item [( )]
Solder the wire from the top 74LS257 of U146 pin 3 to the 2 hole
of the 16 pin socket.
\item [( )]
Install the Memdec chip into its 16 pin socket.
\item [( )]
Inspect the assembly and insert the modified Memdec chip back into U111.
\end {description}
\vspace {.25 in}
\centerline {\Large \em Finishing.}
\vspace {.25 in}
Wow you did it!!!
Put the Z--100 back together using pages 11--18 of your Z--100's User's Manual.
{\sf Tip: You might consider using your ``old'' 4164 chips in your video card.
If you do remember to change J307 down, J305 and J206 to the left.}
\end {document}
--------------------------------------------------------------------
Robcs2531cd@charon.unm.edu (Steve Freed) (01/23/88)
In article <8801211903.AA02813@bellatrix.cs.buffalo.edu.cs.buffalo.edu> benz@CS.BUFFALO.EDU (David Benz) writes: >I have an "old" z100 still running at 5Mhz, with the full >complement of 192K RAM... and would like to add more memory. >...the upgrade sold by FBE, does anybody have any comments about >this product? I installed the FBE upgrade 2 years ago without any problems what so ever. I am quite impressed with the service I have gotten with FBE in the past and highly reccomend them. In fact, when I ordered it, they were far behind in production and I needed the upgrade in a hurry to do a class project... I recieved the kit in a week!! (talk about a dozen nervous students!) > Do I have to modify my computer in any other ways, does it mess up any >programs, etc... No, No, and NO!! >Also, how about the merits of just sliding a card into the s100 cage? >Are their any around that don't cost an arm and a leg, Not that I know of. >is it as simple as just sliding it >in and booting, etc.. Finally, is it possible to do both? Don't know, and don't know. P.S. There are a couple of I.C. warehouses that sell RAM chips (and many others) very inexpensively in a very wide range of manufacurers to choose from. (256k DRAM $1.00 to $2.00 each) AND they are gaurenteed...you must follow their instructions when installing. I have never had one of their chips fail. If you want more details...just ask. no .signature yet. I just got back on the system and, hey, I really don't know where I'm at or who I am so look at the stupid header.