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Zetr0
15th August 2010, 03:59
Hello there my fellow AmiBayers,

After a heap of stuff today I finally got round to this little bit of work for our dear chief maker of trouble JuvUK

What you are about to see is a DIY 2MB CHIP hack for the A600 - this hack grants you an extra 1MB of precious CHIP RAM, to use and abuse as you see fit.

Do not adjust you URL location =D


Now, before we beging you must know that there is a con with this hack - after the modification, the trapdoor expansion port becomes (for the most part) redundant and unusable. (of course you can remove the modification and the expansion port is returned to normal operation).


Tools Required:


A good quality solder (preferably silver bearing)
20cms of Red and Blue 30AWG wire (single core jump wire)
30watt soldering iron (preferably regulated / temp controlled)
Non-Corrosive / No-Clean flux
2x (256Kx16) Memory Modules
Craft / Hobby Knife
Flat Bladed Plyers (no teeth)
Small Nail Clipers (optional)



Skill & Level Required:


Soldering: Intermediate
Multimeter Use: Continuity Testing
Patience: LOTS




Now that you are sitting comfortably.... let us begin... please turn to page 23 in your hackery books, if you missed the hand out come see me after class =)

(loading part 1..... please wait....)


Part 1: Preparing the extra RAM

So lets have a look at what we need

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1670

here we have the solder, the 30AWG (Kaynar) wire, and a couple of compatible 256x16 memory chips

so lets get started eh?


Taking our hobby knife we peal back the legs of the SOJ memory chip

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1673


one by one, gently but firmly we bring them back so we can then do some work on them.

Now we take our flat-headed plyers and straighten out the legs of the SOJ chip.

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1671


We do this in two steps....

step one is to draw out the leg curl at the bottom, the second step is flaten and align the pins straight using the pliers.

Obviously you will need to do this for both sides of the SOJ chip

Now, using the Hobby knife once more we align any legs that are slightly askewed or bent sidways.

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1171


Part 2: Tinning the RAM


Okay now that the SOJ chip legs are splayed out - we can now coat them in solder.

First we use some flux: (no clean & non-corrosive)

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1163


Be liberal with the flux - its there to make your next job easy so make sure theres plenty. If there is a trick to achieving a successful result with this mod then that trick is also solder the inside of the SOJ chip legs too, so get the flux in there as well


Now let me introduce to you a technique called - Loading and Dagging, and no this is nothing to do with those types of parties on the weekend.

First we load the soldering iron with some solder, not to to much by a reasonable blob =)

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1164

Now that we have "Loaded" the iron we can now "Drag" this solder onto the legs of the SOJ chip

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1167


Remember to always do the inside of the legs too

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1168


Now you must perform the exact same thing on the otherside =D


Part 4: Jump Wire Time



Now this Hack uses the A600 motherboard to provide the nessasary addressing required access these new chips, however we must source two signals from the motherboard.

UCAS (Upper Column Address Strobe)
LCAS (Lower Column Address Strobe)

we can source these signals from a variety of places but the best place to get this is from close to the expansion port =)

so how do we get those signals to our new RAM chips?- Well that will be 30AWG Kaynar wire =D


Cut a 10cm length of wire from your spool and then drawback the plastic coating.

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1170


As you can see I use a small set of infant nail clippers, some skill is needed to know the right tension to use, but once you pick it up - you can really fly through the stuff.


Now the two legs we need is pin [28] and pin [29] from the SOJ, to note this I bend the legs back-inward.

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1171


I recommend to use a little flux and Load the soldering iron once again - press down on the leg and (RED) wire untill they unite in holy-smokey-soldery-matrimony

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1172

it should look a bit like this

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1173

Now we do the same for pin[29], its important to have different colour wire or you will be in for a minor nightmare and emotional breakdown later.

Here we are using the blue 30AWG - its kinda fetching dontcha think?

Anyway, as before we tack down the wire, dont be afraid to add a little flux it really will make light work for you.

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1175


Yay!!! \o/ !!!

The controll wires are complete and curled under the chip, now we just striaghten the legs to a vertical position.

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1176


and this little puppy is done!!!

now remember to pay close attention the legs, as they can get skewed and bent laterally as you perform your work, should this happen the just use your hobby knife and gently re-orientate them.

Now that you have done this chip, you now need to perform all of this again on the other one =D



*notes

Should that you get a solder bridge (thats two pins with solder between) then dont panic... move onto the next pins and keep "tinning the legs" come back and pick up the solder bridge with the iron once the solder on the tip runs low.

I would also suggest a little extra flux should the bridge be a little stubborn.


Part 5: Sticking it alltogether


So here the technical bit -


(image to go here)
http://www.guildserver.co.uk/abay-show/A600Chip/AS4C256K16E0.PNG

We are going to be taking these signals (in RED and BLUE) and re-routing them to another point on the A600 motherboard .... where might you ask... well just short of the trapdoor expansion port to be exact.


http://www.amibay.com/picture.php?albumid=150&pictureid=1183


Although there are alternate areas to use for these signals these vary from motherboard revision to motherboard revision, instead, I suggest you use pin 35 and 36 from the expansion socket as its both the simplest and quickest to use.

Of course, you could buzz-out (continuity) with a multimeter where these signals meet under the FDD unit.

(click to super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1674


Mounting (Piggy-backing) the Rams.


Firstly I suggest that laying down some flux on the existing RAMs and lay on some solder to them as well, (similar to what we did earlier with the "Load and Drag" technique"

once done we can slid the new ram on top and adjust its orientation appropriately. Once happy we can simply use the soldering iron to marry the two legs of each chip together.

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1182


A fellow EAB'er recommends trimming the legs of the new chip so that you dont have to solder so far down, I have to admit thats a great idea and will certainly reduce your workload in this part of the modification.

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1179

just make sure you have enough leg to make it to the shoulder of the bottom chip leg.


(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1177


As you can see here the UCAS(red) and LCAS(blue) are shared amongst the two chips, this is then tied to the motherboard expansion socket.


(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1180


Instead of going underneath the expansion port, I decided to use the VIA of pin 35 - which, as luck has it, just above pin 36 =D

(click for super zoom)
http://www.amibay.com/picture.php?albumid=150&pictureid=1183


And that concludes the this part of the hackery, please turn to the last page of your hackery books for tonight's notes.


[I]*notes

marrying the two chips can be tricky, If you are struggling getting the pins together - just relax, put on some enigma or enya and use some more flux. do take up Magno Boots suggestion of trimming the legs of the new RAM chip - this will help emensly.

Remember flux before you solder and you will get the perfect weld, this goes for the motherboard too, when tying down wire to the expansion port or via, then be liberal with the flux =D

jvdbossc
15th August 2010, 11:20
Wow another great hardware hacking guide :) I enjoyed it with a fresh coffee.

I need to improve my soldering skill so it was perfect.

The ram on top is rather funny. lol.

So the only route left is the pcmcia port or an accelerator to get extra mem?

LTAC
15th August 2010, 12:12
EXCELLENT hack Zetr0, thank you very much. :thumbsup:
It only remains to find the Memory Modules and as jvdbossc writes: "we need to improve our soldering skill" :)
It is unfortunate that we can't combine this hack with the trapdoor expansion port :D

Mad_Cat_jr
15th August 2010, 12:15
Nice Zetr0,
Also real good "pr0n" photo's.

It's a joy to look at them.
I have 2 left hands and a A600 with 1MB extra Chip so i don't need this hack.

bazzaq
15th August 2010, 12:59
I really like to read these sort of threads.

Nice hack.

SkydivinGirl
15th August 2010, 17:30
Wow! Simply amazing. :) Another wonderful hack, Zeets!

:bowdown::bowdown::bowdown:

Heather

Zetr0
15th August 2010, 18:56
Thanks for you kind words guys,

I would like to thank my padwan camera girl - my daughter - for her help in taking the pictures need for the expo =)

Mad_Cat_jr
15th August 2010, 19:22
Thanks for you kind words guys,

I would like to thank my padwan camera girl - my daughter - for her help in taking the pictures need for the expo =)

She made stunnin photo's, you could be proud on her.

Merlin
15th August 2010, 20:47
Thanks and Greetz also to the guys over at a1k.org, who came up with this originally.

It was originally translated from German into English (by yours truly :)) over at EAB and then Zetr0 came up with the CAS and RAS lines that are guaranteed to work with any revision of A600.

This photo sequence lays it all out a lot better than the original PDF we thrashed out.

@ Zetr0

How about some commentry on the subject of suitable sources for the 256x16 chips for this hack, along with compatible part numbers for chip manufacturers? That would really be putting a cherry on top of this cool How-To.

Cheers

skippy
28th September 2010, 01:06
@Zetr0:

Can one safely assume that by routing UCAS / LCAS from the trapdoor Pin 35/36 to strobe the column addressing scheme this makes the expansion redundant?

(IE: Similar to the re-routing technique used with an A500 1MB ChipRAM upgrade MOD and JP7A/Trace cut to expansion slot.)

Regards,

Skippy.

Ed.D
28th September 2010, 01:36
Can only one chip be piggy-backed?

I can imagine A600 owners cutting holes in their cases and having chip towers poking through. :)

rkauer
28th September 2010, 02:43
No more than one set of chips, mate: the place is used only for chip RAM, and the Amiga can only have 2Mb of it, no matter what.

Merlin
28th September 2010, 09:18
@skippyar

Yes, the trapdoor expansion is redundant after this hack.

dapsaille
30th September 2010, 00:36
Just tried but ...

it seems that i've mis-juged my capabilities to ironing at the same time of watching a tv show = yellow/green boot ...

Time to get some rest and tomorrow i will clean up my dirty solders :lol:

Ceedy
22nd February 2011, 19:49
Any links to the photo's that seem to have gone walkabout ?.

jvdbossc
22nd February 2011, 20:21
Zetro had some problems with images, he might be able to restore them.

PS: I think there was a for sale thread for this mobo:) I remember passing it because I needed a clock port on the a603

Zetr0
22nd February 2011, 21:32
sorry guys, the server is closed so the images are down, I will - upload these again over the coming week.

Ceedy
22nd February 2011, 21:46
sorry guys, the server is closed so the images are down, I will - upload these again over the coming week.


great Thanks... My weller's all a Quiver waiting !! :lol::lol:

chiark
22nd February 2011, 21:53
My weller's all a Quiver waiting !! :lol::lol:

As the actresss said to the... Oh, this is too easy: there's no sport in this!

rkauer
12th March 2011, 19:18
I need the pictures back, too.

UberFreak
29th March 2011, 15:48
This is a great little hack, did it a little over a year ago :)

rkauer
30th March 2011, 21:27
A brazilian user did this very same hack (he used a few hints I gave him, guess from where I learnt about? :)), but he used a slight different approach.

He piled up the two chips over just one RAM chip, as when piggybacking two very near chips as on the A600 will turn soldering into a hard procedure, at best.

Lemme show the result:
http://www.victortrucco.com/Commodore/ExpansaoA600/DSC00717.jpg

Zetr0
31st March 2011, 01:21
Hmmmm


3 wires instead of 4 wires.... easier to bond the bottom chip, test and avoid the floppy drive.

I think this is a result!

RAM Tower Hack for the WIN!!!! :thumbs up:



@rkauer

my friend, what's the hackers name so I can credit him in my revised "how to" ?

rkauer
31st March 2011, 05:13
Yes, I'm inclined to agree with you: RAM tower FTW!

Victor Trucco is his name. A good guy that was one of the creators of the floppy emulators.

Zetr0
1st April 2011, 03:24
@rkauer

my thanks indeed for sharing!

I shall credit Victor on the re-do and image update, as I seem to of lost the originals =(

they might be on the other laptop - but I do love the simplicity of Vic's take on it... its almost (if not so) like hardware poetry =)

Merlin
1st April 2011, 09:25
@ Zetr0

Please don't forget to credit the guys over at a1k.org, that came up with this hack in your update.

Simon_G
9th September 2011, 11:34
Zetr0, any chance of those pics being uploaded again? Was looking at the possibilities fo doing this mod but cannot see what I am doing :(

Thanks in advance.

rkauer
10th September 2011, 06:58
If you don't mind reading in Brazilian Portuguese: http://www.victortrucco.com/Commodore/ExpansaoA600/ExpansaoA600.asp

Allen1
10th September 2011, 13:49
If you don't mind reading in Brazilian Portuguese: http://www.victortrucco.com/Commodore/ExpansaoA600/ExpansaoA600.asp

That's Brilliant rkauer,

now that wouldn't be you that is mentioned in the comments would it :D

I did a google search using part of your link ie :- ExpansaoA600.asp

This allowed me to use google translate to read everything in English, that is a brilliant idea to piggyback and solder the two acquired memory chips together, then solder it/them onto the one memory chip on the Amiga. No problems with the floppy drive screw and less legs to solder on the actual Amiga :thumbsup:

fitzsteve
10th September 2011, 13:51
Zetr0, any chance of those pics being uploaded again? Was looking at the possibilities fo doing this mod but cannot see what I am doing :(

Thanks in advance.

Zetr0 lost these pics AFAIK, but I sent him a spare A600 Motherboard recently which he is going to apply the hack with some new knowledge so I expect he will upload new ones soon :)

Maybe a new guide too :thumbsup:

Zetr0
10th September 2011, 14:03
Indeedy

I lost the pics in a system failure, however I didn't worry as they were hosted on my server.... alas - sever sub-ended, they didn't offer me the correct contract to continue so I lost what was on there as well.... even a very early alpha AmiBay =(

Anyway, these things happen and its not healthy to get angry at faceless useless organizations - its a waste of protien and time that I could use to build / do somthing else.


Now, I plan to do the RAM tower modifcation with a little twist, as an omarge to the one posted by rkauer - which I believe was done by Victor Trucco


@rkauer

Would Victor Trucco be TabajaraLabs or have I got very confused again ?


Anyway, the RAM tower is a better implementation of the upgrade/hack as

1. it uses less wire
2. it is easier to solder
3. it physically fits better (away from the Disk drive Screw)
4. it looks cool ;)

I have the mobo here from stevie so with a bit of luck and time we should be good to rock =D

rkauer
12th September 2011, 05:57
Nope, Tabajara is a member here (aka Alexandre, a great guy in more than one sense).

@Allen1: yours truly. :)

BinKino
12th September 2011, 15:53
no pictures?

can give you space for them

Zetr0
12th September 2011, 18:15
@BinKino

unfortunately its lost pictures =(

I will scourer my file store again tonight to see if they were backed up... although I didn't find them last time I looked.

Simon_G
12th September 2011, 20:39
I have the mobo here from stevie so with a bit of luck and time we should be good to rock =D

Look forward to seeing the updated pics and methods :)

Virge
27th October 2011, 13:24
Hi all :D

After this hack the trap door will work to use A604 ( 1mb memory expansion ) ?

Regards
Pedro Henriques

AndyLandy
27th October 2011, 13:27
Hi all :D

After this hack the trap door will work to use A604 ( 1mb memory expansion ) ?

Regards
Pedro Henriques

No, sadly not. You can only have 2MB of ChipRAM. If you do this hack and plug in an A604 you'll just end up shadowing RAM, you won't be able to use any more.

@Zetr0: Sorry to hear about your fileserver crash. I had something similar recently. I've lost all my A3000 and A4000 pr0n pics. :(

Virge
27th October 2011, 13:36
Ok Andy.
Thanks for the info ;)

Regards
Pedro

kire_online
4th December 2011, 08:25
Is this chip OK for this hack;

MT4C16257 4-MBIT (256K x 16) FPM DRAM

I'll be attempting this hack on my A600 soon, need to source the chips first.

Methanoid
12th July 2012, 14:06
Ah, found the thread.

So if this disables the expansion slot, why do it? I mean if you fit an A604 you get 2Mb chipram AND can use the Indivision ECS?

I may be being dense here so somebody help me out !! :lol:

Zetr0
12th July 2012, 14:17
lol

Afternoon!

the 2MB chip just uses the data and address lines that are at the edge connector - just sitting on top of the other chips. it uses two jump wires to pickup the RAS and CAS signals needed to switch to the upper memory.

I shall hunt for some pics

Zetr0
12th July 2012, 14:21
Aha!

I found them!

djos
12th July 2012, 14:26
All the pics on page 1 are broken :(

EDIT: DOH, finally read thru the rest of the thread. :(

Zetr0
12th July 2012, 15:24
pics on front now re-done!

Methanoid
12th July 2012, 15:34
You must have good eyes to solder that small stuff... Just wait until you get to MY age and your eyes are ****/shot :lol:

nice job... looks really neat too

Zetr0
12th July 2012, 16:10
to be honest, its not my best job, I felt that both FOL's and Magno Boots efforts were better =)

AmiNeo
12th July 2012, 16:29
Great hack Keith! I may do this myself sometime :D

Is that doable with any larger chips by chance? :unsure: Could we for example make a 3mb A600 by installing a 2mb chip?

---------- Post added at 15:29 ---------- Previous post was at 15:27 ----------

Something else I've thought of too... Would it be possible to desolder the current 1MB onboard and replace it with a larger chip? :unsure: I guess someone would have done that before now if it were possible.

Zetr0
12th July 2012, 16:53
Sadly no, there is only enough logic (RAS/CAS and Agnus) to go upto 2MB total.

AmiNeo
12th July 2012, 17:27
Sadly no, there is only enough logic (RAS/CAS and Agnus) to go upto 2MB total.

Ah fiddlesticks. I wondered where the limitation was. Oh well, I know now atleast :lol:

AndyLandy
12th July 2012, 18:29
Not to mention that Agnus won't talk to anything more than 2MB of ChipRAM anyway.

AmiNeo
12th July 2012, 19:18
:picard I feel so noob now :lol:

AndyLandy
12th July 2012, 19:26
:picard I feel so noob now :lol:

That's fine. I'm a noob too, I just kept learning stuff and repeating it and now people seem to think I'm some kind of expert. :lol:

AmiNeo
12th July 2012, 20:22
:thumbsup: :D

johnim
12th July 2012, 20:40
nice guide mr z thanks for the pics reupload :thumbsup:

80sFREAK
13th July 2012, 01:23
Sadly no, there is only enough logic (RAS/CAS and Agnus) to go upto 2MB total.

How about some extras - small circuit, which will control address lines and access to RAM?

rkauer
13th July 2012, 04:56
Not to mention that Agnus won't talk to anything more than 2MB of ChipRAM anyway.

Not exactly true. One can install more 2Mb of RAM in the A600 (in fact, 1.8Mb in the RANGER area), but for that more logic must be added.

A multiplexer to decode the RAM, some glue logic and extensive fiddle with the address lines.

But that is just too much to do inside the cramped A600 board. Stacking three or four memory chips can be a total nightmare and probably the case will not have enough clearance to be closed again.

SpeedGeek
13th July 2012, 14:52
Not exactly true. One can install more 2Mb of RAM in the A600 (in fact, 1.8Mb in the RANGER area), but for that more logic must be added.

A multiplexer to decode the RAM, some glue logic and extensive fiddle with the address lines.

But that is just too much to do inside the cramped A600 board. Stacking three or four memory chips can be a total nightmare and probably the case will not have enough clearance to be closed again.

What AndyLandy and ZetrO said was correct the maximum amount of RAM addressable by Fat Agnus is 2MB. Sure you could hack in enough extra logic to map some more "Slow-Fast" memory in Ranger space but it would be a lot of work with not much reward. In fact it would probably be just as easy to hack in some SRAM in Ranger space and have real Fast memory performance! ;)

jimbob
22nd September 2012, 17:00
Hmm, I have one more A600 than I have trapdoor expansions, this looks like fun. Does anyone know if an upper RF shield will fit over the extra RAM chips?

Also, are either of these suitable for this this job -

http://www.ebay.co.uk/itm/250971348365?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

http://www.ebay.co.uk/itm/110291476487?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

jimbob
25th September 2012, 21:06
er, I posted a few days ago here but it seems not to have emerged from moderation. Perhaps because I included ebay links? I thought that was permitted in non-trading threads?

Anyway, I wanted to know if some chips for sale there were suitable for this mod.

Number 1

Part Number = HM514170CJ7
Manufacturer Name = Hitachi Semiconductor
Description = General Purpose Dynamic RAM - Fast Page Mode
Number of Words = 256k
Bits Per Word = 16
t(acc) Max. (S) = 70n
tW Min (S) = 130n
Output Config = 3-State
P(D) Max.(W) Power Dissipation = 1
Nom. Supp (V) = 5
Package = SOJ
Pins = 40
Military = N
Technology = CMOS




Number 2

P/N K4F401611D-JC60
IC DRAM 256K x 16 SOJ-40
MADE BY SAMSUNG

Also, does anyone know if the upper RF shield will fit after this has been done?

piacc64
25th September 2012, 22:10
i tomorrow add the ram on 600hd with upper metal shield, tomorrow report if all ok

rkauer
26th September 2012, 03:57
er, I posted a few days ago here but it seems not to have emerged from moderation. Perhaps because I included ebay links? I thought that was permitted in non-trading threads?

Anyway, I wanted to know if some chips for sale there were suitable for this mod.

Number 1

Part Number = HM514170CJ7
Manufacturer Name = Hitachi Semiconductor
Description = General Purpose Dynamic RAM - Fast Page Mode
Number of Words = 256k
Bits Per Word = 16
t(acc) Max. (S) = 70n
tW Min (S) = 130n
Output Config = 3-State
P(D) Max.(W) Power Dissipation = 1
Nom. Supp (V) = 5
Package = SOJ
Pins = 40
Military = N
Technology = CMOS




Number 2

P/N K4F401611D-JC60
IC DRAM 256K x 16 SOJ-40
MADE BY SAMSUNG

Also, does anyone know if the upper RF shield will fit after this has been done?

Your link was not approved because your low post count at the time.

Yes, both are suitable for this hack.

jimbob
27th September 2012, 19:50
er, I posted a few days ago here but it seems not to have emerged from moderation. Perhaps because I included ebay links? I thought that was permitted in non-trading threads?

Anyway, I wanted to know if some chips for sale there were suitable for this mod.

Number 1

Part Number = HM514170CJ7
Manufacturer Name = Hitachi Semiconductor
Description = General Purpose Dynamic RAM - Fast Page Mode
Number of Words = 256k
Bits Per Word = 16
t(acc) Max. (S) = 70n
tW Min (S) = 130n
Output Config = 3-State
P(D) Max.(W) Power Dissipation = 1
Nom. Supp (V) = 5
Package = SOJ
Pins = 40
Military = N
Technology = CMOS




Number 2

P/N K4F401611D-JC60
IC DRAM 256K x 16 SOJ-40
MADE BY SAMSUNG

Also, does anyone know if the upper RF shield will fit after this has been done?

Your link was not approved because your low post count at the time.

Yes, both are suitable for this hack.

Understood and thankyou. I'll be having a go at this soon.

Elgen
3rd October 2012, 13:06
Hi, old thread I know.

I'm thinking of doing this hack. I have some 60ns DRAMs of the correct type; will that be a problem (the ones already in the my A600 are 80ns)? But I figure as since the 60ns and 80ns are just max times, I should be a'okay?!

Also, to me it looks like all the signals I need for the hack are available at the trapdoor port, so wouldn't it be possible to attach the extra DRAM there (via an compatiple egde-connector) instead of piggybacking the on-board DRAMs? Sort'a'like a DIY expansion-module };-P
I kind of the like the idea of being able to remove the hack again in a snap };-P

The DRAMs I have are these btw (look at the price };-P): http://www.ebay.com/itm/251042002668?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

mamejay
10th October 2012, 04:23
Awesome guide!! Exactly what I was looking for.
Now I just purchased these from the other bay

M11B416256A-25J Manu:ELITEMT Encapsulation:SOJ-40,256 K x 16 DRAM EDO PAGE

Not sure if they will work. From what I can find out they will but please let me know if I have ordered the wrong chips.
Thanks

rkauer
10th October 2012, 06:23
Wrong chips, sorry.

You need SOJ40, 512k x16 DRAM (other parameters are irrelevant).

mamejay
10th October 2012, 06:53
Wrong chips, sorry.

You need SOJ40, 512k x16 DRAM (other parameters are irrelevant).
Oh really?? From the first thread it mentioned 256k x 16 DRAM so that is what I looked for.
It does make sense it needs to be the 512K x 16 chips.

Are you sure as above you actually told another member the 256k x 16 was ok for this hack.

Elgen
10th October 2012, 12:51
Wrong chips, sorry.

You need SOJ40, 512k x16 DRAM (other parameters are irrelevant).
Oh really?? From the first thread it mentioned 256k x 16 DRAM so that is what I looked for.
It does make sense it needs to be the 512K x 16 chips.

Are you sure as above you actually told another member the 256k x 16 was ok for this hack.
I think rkauer's a bit tired/drunk or something };-P
...it IS 256K x 16 chips you should use.
What might have confused him (and you) is, that even though the total number of words is only 512K (=256K x 2 chips), the words are 16 bits wide; and RAM is still measured in bytes/KB/MB...so it's still 1024MB.
Btw, the 2 DRAMs already sitting in the A600 are also 256K words each };-P

mamejay
10th October 2012, 21:58
Yeah started looking it up. I think the ones I got should be fine to use

rkauer
11th October 2012, 00:06
I think rkauer's a bit tired/drunk or something };-P

Pick one!:lol:
:p

mamejay
11th October 2012, 01:42
I think rkauer's a bit tired/drunk or something };-P

Pick one!:lol:
:p


:thumbsup:

Elgen
11th October 2012, 11:08
};-P

Elgen
17th October 2012, 12:49
I'm trying to do this hack, but instead of piggybacking on the rams already in the miggy, I'm trying to use the connections in the trapdoor port.
In my first attempt, I used ribbon wire and a PCI port (as it has the same pitch.) The two drams I've piggybacked together with the 2 RAS-signals not connected; they go to RAS0 and RAS1. For decoupling I've used 1 2.2uF for the whole rail and 3 220nF (one on each of the supply inputs on piggybacked ICs).
Unfortunally it doesn't work };-(
WB finds the extra ram fine (it shows on the top of the screen) but when trying to use it (ie WHDLoad), I get all sorts of errors.
I need suggestions on what to do next...what could be the problem. In a txt Phiscube suggested that it could be crosstalk...any other suggestions?

The next I'm gonna try two new DRAMS (of the same kind, 60ns), still with the connections in the trapdoor. But this time I'll use kynar for the signal lines and normal thin wires for the supply. The idea is, that the signal lines can be about half the length as before and they wouldn't quite as "parallel", maby preventing crosstalk. For decoupling I'll use the same as before.

What do any of you experienced miggy hackers think???

piacc64
17th October 2012, 13:20
if wb show 2 mega, the ram is ok

more game with whdload need more ram

Elgen
17th October 2012, 13:52
I've also tried testing with 2 progs found on Aminet: MemCheck and Amnesia...they test with different patterns and both show random errors in the extra 1Mb...
That's also the reason I suspect either crosstalk, insufficient decoupling or maby timingproblems?? Is it a problem that I use 60ns instead of 80ns (with SRAMs, that I usually work with in my arcade repairs, that would pose no problems as long as you use faster than spec'ed); could it be that the refresh cycle on 60ns DRAMs is also shorter than on 80ns???

Zetr0
17th October 2012, 18:07
@Elgen
faster ones wont be the problem, its possible one or more of them are damaged.

if at all possible I would swap one out for another one, see if this alleviates the problems found in the memory testers - if not, try the other... failing that then its most certainly your hook-up.

do you have a picture of your mod?

Elgen
17th October 2012, 18:45
Not of the construction as it looks now, I have a couple of the process:

http://img.tapatalk.com/d/12/10/18/ene6u7uv.jpg
The IC to be piggybacked

http://img.tapatalk.com/d/12/10/18/7ydyge7e.jpg
Piggybacking

http://img.tapatalk.com/d/12/10/18/egazumuv.jpg
The rainbow ribbons (the long one is for RAS on the piggybacked; the position of the wire is NC anyway)

http://img.tapatalk.com/d/12/10/18/pe9e3e7e.jpg
First ribbon attached.

http://img.tapatalk.com/d/12/10/18/ybe3y9ug.jpg
And now 2nd one.

http://img.tapatalk.com/d/12/10/18/u7ume5av.jpg
First couple of wires soldered to the PCI.

http://img.tapatalk.com/d/12/10/18/e4u5u3ub.jpg
http://img.tapatalk.com/d/12/10/18/zana6ygy.jpg
Used these mappings...think two columns are switched in the lower pic };-P

http://img.tapatalk.com/d/12/10/18/jeru5a3e.jpg
WB screen before...

http://img.tapatalk.com/d/12/10/18/tudate2a.jpg
and after.

I'll try to get a pic of the mod as it looks now later tonite...I'm at my parents-in-law with the wify and kids atm };-P

Elgen
17th October 2012, 22:04
...and here are 2 pics of the construction as it looks now.
http://img.tapatalk.com/d/12/10/18/tyjeqe4u.jpg
http://img.tapatalk.com/d/12/10/18/egurygam.jpg
The red wires are +5V. I've chosen to use that instead of the outermost wires in the ribbon in an attempt to avoid interference with the signals. The blue horizontal ones are GND. I have one 2.2uF in each end of the whole power rail for the ICs and then one 220nF across each supply entry to the ICs (3 of them).

Zetr0
18th October 2012, 00:45
@Elgen

To be honest, It looks great, I am a sucker for SPECTRA STRIP IDC cable - however I think you may have over-engineered it.

It wouldn't surprise me if those capacitors you installed for both smoothing and decoupling could be introducing noise in to the very tight circuit.

But because of your jig, I am unsure how to really suggest fault finding without tearing it all apart =(

You can test each 512K bank separately and it will appear as 1.5MB on the Amiga - do you have other appropriate / compatible 256k16 chips?

Elgen
18th October 2012, 01:18
Thnx for your good advise and cheer up };-P

Oh yes, I have lots (Muahahaha!) When I first read this thread, I went looking at the other bay and found this };-P http://www.ebay.com/itm/251042002668?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

I've just tried desoldering the DRAM-couple. I couldn't "divorce" them, so made a new couple and soldered them on. But to be honest, it was a mess. These ribbons are not meant for soldering in the first place, so trying to desolder and then resolder was just a no-go'er. The miggy hangs at boot with a white screen. I'm too tired to do anymore tonite. But tomorrow I'll make an attempt with kynar instead...(I am a bit sad to loose the rainbow ribbons, as I really love how they just look like candy ready to eat };-P)

Btw, what do you think about the length of the signal wires...could that pose a problem? Should I try to make them shorter?

piacc64
18th October 2012, 09:42
short is best

Zetr0
18th October 2012, 13:38
@piacc64

I suspected a short at first my friend, but should there be a short in the address lines then the first two banks would fail as well - hence a green or yellow screen (pending the stuck address)

Its more likely a dodgy chip or noise on the circuit.

piacc64
18th October 2012, 13:53
35254

i release this
first i have remove from socket pin for lcas and ucas
second i have soldered a ram on socket
3 add a ram on the first ram exclude ras
4 soldered 3 wire to pci connector
5 moved cap for insert socket

Phipscube
18th October 2012, 15:35
I think your cable length is ok Elgen, it seemed much longer on the pic I saw before you'd soldered to the PCI socket. But there could still be some interference coming from somewhere (internal or external) or a bad chip (even though I'd expect to see a fault at boot, but you never know).

But to be completely safe, and bug fix friendly, I would wedge a bit of vero board between the PCI pins (you got more than one didn't you? so no need to scrap this one), solder a couple of redundant pins to the boards strips to secure it, then hotglue or 3M double sticky pad (my fave) 2 fresh DRAM's upside down next to each other as close to the port as possible, then meticulously and slowly kynar each connection from each pin separately to the "PCI" Socket (I'd also do this over some days to be fresh and take my time so I know each wire is bang on, trust me it pays to do it this way).

Leave the caps off to start with and see how it goes, Then you can fault find much easier than having the two DRAMS soldered together (and replace them easier too). You can then add caps if necessary later. :)

Elgen
18th October 2012, 15:48
Ahh, upside-down! Les, you're a genius...now why didn't I think of that myself? };-S sound so much easier.
And then I'll do first one and then test (as Zetr0 suggests) };-P
Hmmm just thinking... Sockets would be even better, but it seem like they are a bit hard to come by...

Phipscube
18th October 2012, 18:03
Yes, they are hard to find, You might find some on old PC graphics cards with them on, but you have to sacrifice the PC card as you have to rest it on two pieces of wood or metal, sockets facing down on a workbench and heat gun the other side of the card till they fall off. ;)

piacc64
18th October 2012, 18:43
yes upside-down

i have removed socket from old pci vga card 1 mega vga (sockets for second mega), i buy for 1 used

Elgen
24th October 2012, 12:30
Heureka! I got it working };-P and I send my kind regards to Faraday!

Okay, here's the story:

I redid the construction with a new "married couple", but this time taped them up-side-down (thnx Phipscube) on a piece of cardboard taped to the PCI connector.

http://i1189.photobucket.com/albums/z437/ElgenDK/A6002MBHack/931A7FAA-A09E-4DF6-8639-B59675FDAC86-405-00000035AAF6135D.jpg

http://i1189.photobucket.com/albums/z437/ElgenDK/A6002MBHack/9F15BB27-414D-46F0-840F-4E994B5E0174-405-00000035BBA977E7.jpg

(I've cut a rectangular hole in the cardboard, to make easy access to the pins on the underside when soldering)

I did all the signal wires with kynar (red ofcause, cause it works best) and the supply wires with thin singlecore wires.


The coolest thing about kynar wires is, that they are so small and thin };-P
However the most annoying thing about kynar wires is, that they are so small and thin };-S

(don't have pictures of finished soldering job yet, as I got a bit too eager)

Now, when plugged in, WB found the extra RAM. But the MemCheck program I use would sometimes pass and sometimes come up with a couple of errors. Also when playing WHDLoad games that uses the extra RAM (ie Cinemaware-stuff) I got random crashes.
Hmmm, instability of some sort. Maby it's a smoothening problem?! Tried adding 2 220nF caps, one in each end of the couple, but that only made things worse };-(

It was then I came to think of good ol' Faraday and his cage...maby the instability was caused by electromagnetic interference emitted from the other circuits (or maby just general radio noise). So I first wrapped the construction in paper to insulate and then in tin foil (yes, the same kind I use to wrap the school lunch for my kiddies };-P)
I plugged it in again and connected my Faraday Cage to ground.

http://i1189.photobucket.com/albums/z437/ElgenDK/A6002MBHack/9DE7DEF1-1FC9-48D5-A793-5AAE9D485A72-4340-000003D54AD1A605.jpg


"Dad, did you put chips in my lunch pack for dessert?"
"Sure did son, but not the potato kind };-P"

And now, my friends, it just frakkin' works!!!

It passed the memtest 5 times in a row, and I played DefenderOfTheCrown for an hour without any crashes at all.

Ofcause I will have to make a nicer solution...I think I have some proper shielding metal from a scrapped "something" in the pile somewhere };-P

When all done, I'll do a little write-up of it all on my blog and post a link.

luy32
24th October 2012, 22:46
very nice mod and i like it :thumbsup:

is this mod compatible with KIPPER2K s 4MB board ?
in other words, will be there 2MB chip and 4 MB fast ?

piacc64
24th October 2012, 22:53
sure, i have tested, work fine with 2 mega chip ram and 4 mega fast autoconfig

luy32
24th October 2012, 23:00
sure, i have tested, work fine with 2 mega chip ram and 4 mega fast autoconfig

:thumbsup: ok then, time to learn soldering ;) , try to find the drams
and contact kipper2k

it would be a interesting winter ;)

Elgen
24th October 2012, 23:44
These are pretty cheap http://www.ebay.com/itm/251042002668?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
And you could sell the ones you don't use...

Phipscube
25th October 2012, 13:25
Awesome work Elgen mate! :)

Elgen
29th October 2012, 22:16
Finally finished my A600 1MB Chip RAM trapdoor expansion...works like a charm. And looks pretty too imo };-P
http://elgensrepairs.blogspot.dk/2012/10/homemade-1mb-chip-ram-expansion-for.html

mamejay
30th October 2012, 01:43
Excellent work Elgen!
I was looking to do just the normal hack of piggy backing the original chips. Would that method cause memory issues?
Would you need to insulate those also?

Elgen
30th October 2012, 05:42
Thnx, and no I don't think so. The ICs themselves don't need shielding. It's the fact that I use (unshielded) wire for address- and datalines, that exposes the circuit to electromagnetic interference.

mamejay
30th October 2012, 07:54
I just finished doing my one and it works perfect!! no errors using the memory test.
Everything is working happily with Kippers 4MB fast ram board so I am happy.

Thanks for the tutorial!!

rkauer
31st October 2012, 03:35
Finally finished my A600 1MB Chip RAM trapdoor expansion...works like a charm. And looks pretty too imo };-P
http://elgensrepairs.blogspot.dk/2012/10/homemade-1mb-chip-ram-expansion-for.html

@Elgen: pssst!
http://aminet.net/package/docs/hard/Tabajara

By yours truly.:)

Elgen
31st October 2012, 04:00
@rkauer: Sweeeeet };-P Have you got any pics of one you've made?

rkauer
31st October 2012, 05:56
Nope, binned that atrocity ages ago (lol) and grabbed a proper C= A601 instead.

Of course I used a 72pin SIMM instead stacked RAM chips.

If I do it again the future I'll drop this pesky DRAM use and stick to SRAM. No more problems.

I really hate DRAM.

Elgen
31st October 2012, 08:13
I thought about using SRAM too, as I'm much more familiar with them from doing arcade repairs. But how would you translate the 4 strobe signals into something like output-enable/chip-enable signals for the SRAMs? I couldn't figure that out...so DRAM it was.

And I hate'em too btw };-S

Elgen
8th November 2012, 19:54
If you know how to do that rkauer, I'd really like to know...

rkauer
8th November 2012, 23:50
If you know how to do that rkauer, I'd really like to know...
Interesting reading about the matter:
http://bitcycle.org/retro/spectrum/SRAM_replacement/

MikeAm73
13th February 2013, 13:55
Hello to all,

I just finished using the "piggybacking" method on my A600...

I soldered the two chips using Trucco instructions and after I soldered the two chips on one of the two originals on mb.

After I soldered the three wires and ... nothing ...
the A600 was reading the kickstart (sequence of grey screens) and then froze.

I checked the pins one by one and everything was ok.

The problem is that my motherboard is different from the one that Trucco desribes in his method and then I used the alternative points as described in the first post.

No operation as long as I have not reversed LCAS and UCAS.

Now the Amiga starts and recognize dual memory. :arms

Now I have to quietly test the memory for errors.
Wich program cai I use for this test?

For now, I tried the workbench and a couple of games, and everything seems to be fine.

Thanks to all ... fantastic forum. :bowdown:

Zetr0
13th February 2013, 17:10
GVP have some memory tools, this is what I generally use - you can find the memory tested on the Faastprep disk - if you search amiga.resource.cx for pretty much any GVP product you will find an install disk and on that is a memory checker.

Alternatively there is AmiNet =)

MikeAm73
13th February 2013, 18:56
GVP have some memory tools, this is what I generally use - you can find the memory tested on the Faastprep disk - if you search amiga.resource.cx for pretty much any GVP product you will find an install disk and on that is a memory checker.

Alternatively there is AmiNet =)

Ok, thank you Zetr0.

I have already downloaded an install disk for my GVP for A2000 (HC +8);
I have not yet used the disk but I will check into it.

Otherwise I will try to Aminet ;)
Thank you very much.

Good evening.

cosmicfrog
14th February 2013, 01:49
a simple way is to fill up the ram disk, ok this only tests writein to ram and not reading but still if you have nothing else available it can still be a worth while test to do

AmmoJammo
11th March 2013, 05:04
I take it HYB514265BJ-45 are suitable?

edit: and as has already been asked, could chips with double the capacity be used to replace the original chips on the board?

Zetr0
13th March 2013, 18:46
I take it HYB514265BJ-45 are suitable?

edit: and as has already been asked, could chips with double the capacity be used to replace the original chips on the board?

sadly not without extra circuitry to convert the RAS signals to higher address signals - it could be done but it would require a bit of effort.

VincentGR
4th July 2013, 13:19
Amazing!!!

Do you have a link for the chips?

Thanks in advance.

waltermixxx
19th August 2013, 07:48
I managed to find a couple of old Trident 9680 graphic cards at a nearby Electronic Surplus store... ( also picked up some ram for my a2091 scsi card from an old 286 motherboard...and 4 scsi hard drives ) all for $cheap

here are some pics of my Ram hack:

http://www.flickr.com/photos/66577016@N00/9541641321/in/photostream/

in that photo stream you will also find pictures of my a2091 14mhz hack along with my modded U12 rom :) and added 1 meg of ram :)

Cheers :)

mfilos
19th August 2013, 10:10
Nice mod there man kudos.
This is a nice hack for someone that doesn't need RTC or SD/FF.

Btw I enjoyed the RPi hacks as well :)

waltermixxx
19th August 2013, 22:41
if I decide I want to get one of those trap door memory upgrades with built in clockport. Can I dissable the onboard mod by disconnecting the
UCAS (Upper Column Address Strobe)
LCAS (Lower Column Address Strobe)
lines to the two chips? or would their presence interfear if not enabled?

---------- Post added at 16:41 ---------- Previous post was at 14:51 ----------

I did find this tidbit on a way to perhaps dissable the ram hack:

http://www.a1k.org/forum/showpost.php?p=604304&postcount=135

instead of of going to the motherboard, the two signals can go to the middle of a double pole double throw switch with pin 35 and 36 from expansion port on one side, and +5 volts on the other...

:) I enjoyed the hack but there is a lot of value in the amiga kit board with Ram, clockport, and ecs scan doubler thingy socket :)

80sFREAK
20th August 2013, 02:24
I have somewhere bare Sega Saturn PCB and IIRC there is 4 256k*16bit DRAM chips, so i know, whats gonna happened next :whistle:

jimbob
6th December 2013, 14:10
I've done this cunning mod twice now but I neglected to thank you by providing a little pr0n the first time so here we go -

Prepare the chips -

http://i181.photobucket.com/albums/x249/doojum/Amiga/piggyback%20hack/CASwires1_zps07d3cea6.jpg (http://s181.photobucket.com/user/doojum/media/Amiga/piggyback%20hack/CASwires1_zps07d3cea6.jpg.html)

http://i181.photobucket.com/albums/x249/doojum/Amiga/piggyback%20hack/chipsprepared_zps00a46d37.jpg (http://s181.photobucket.com/user/doojum/media/Amiga/piggyback%20hack/chipsprepared_zps00a46d37.jpg.html)

Chips installed -

http://i181.photobucket.com/albums/x249/doojum/Amiga/piggyback%20hack/chipsinstalled_zps6e0e2352.jpg (http://s181.photobucket.com/user/doojum/media/Amiga/piggyback%20hack/chipsinstalled_zps6e0e2352.jpg.html)

Success! There may have been some swearing before this last photo was taken. I didn't make a very good job of soldering the chips on first time. :Doh: Had quite a few dodgy connections so I ended up taping off the area and giving it the hot air. That did the trick. :thumbsup:

http://i181.photobucket.com/albums/x249/doojum/Amiga/piggyback%20hack/chipsworking_zps2368f04f.jpg (http://s181.photobucket.com/user/doojum/media/Amiga/piggyback%20hack/chipsworking_zps2368f04f.jpg.html)

I don't think I'll do this again. Neat trick but very fiddly and a bit tricky to undo it if you mess up.