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   Copy of Rampak 32K
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   Author  Topic: Copy of Rampak 32K  (Read 591 times)
olivierg
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Posts: 34
Copy of Rampak 32K
« on: May 21st, 2016, 11:08am »
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Hi All,
 
I have create copy of RamPak 32K, it's very low cost, under 5 euro (without labor). It is more interesting to buy it used.
 
http://www.gossuin.be/index.php/psion-organiser-ii-rampak-32k
 
Bye
Olivier
starhawk
Power Member




   


Posts: 78
Re: Copy of Rampak 32K
« Reply #1 on: May 22nd, 2016, 11:17pm »
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Very nice! I see a couple of potential mistakes on your schematic (at the other end of the link), however...
 
(1) You have Pin 14 (VCC/+V) of each 4024 wired to ground. That's going to cause smoke, for sure!
 
(2) The memory chip in the schematic is a ROM chip, which does not itself need battery backup. If you substitute a static RAM chip, however, that's different. I did not look up the ISSI chip you used in actual construction, so I'm not 100% sure what to say here...
 
(3) Are the address lines coming off the 4024s indeed not supposed to be contiguous? (A1...A7 / A8...A14) The outputs of those two chips, as generating the address signalling, look a little odd to me, because they kind of jump all over the place. I'm not sure that this would actually affect the read/write operation of a RamPak, given that it appears to operate without the ability to address individual segments of the memory chip on their own -- but it does seem kind of odd...
olivierg
active Member




   


Posts: 34
Re: Copy of Rampak 32K
« Reply #2 on: May 23rd, 2016, 8:12am »
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Hi,
 
1) I do not see this error in the diagram. The pin 14 is connected to VDD, which is the battery power and the slot psion via the diodes and transistors.
 
2) I used to do the schematic drawing of a ROM that is pin compatible with the ram. I will change the schema for this does not cause confusion.
 
3) No there are not contiguous, it's not important. I based on the original diagram of a Rampak. I think that is optimized for the design of the PCB. This is only a problem if you want to read the memory with an external programmer. ROM files of various programs which I found on the site not used much if not written via a Psion.
 
Thank you
Olivier
starhawk
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Posts: 78
Re: Copy of Rampak 32K
« Reply #3 on: May 23rd, 2016, 3:25pm »
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Lower-right corner, where Pin 14 of IC4 and IC5 are connected to ground.
 
Whoops, that's the gates not the 4024s. Still... you do that in real life, you get smoke...
olivierg
active Member




   


Posts: 34
Re: Copy of Rampak 32K
« Reply #4 on: May 24th, 2016, 7:33am »
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Hi,
 
The pin 14 is connected to VDD and pin 7 is connected to GND.
I have updated schematic with more space.
 
Thanks
Olivier
MartinReid
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Posts: 78
256k Rampak is it possible?
« Reply #5 on: Sep 23rd, 2017, 9:36am »
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Dear Olivier
 
I am posting here rather than emailing you direct in case others are interested.
 
Did you ever have a go at creating a 256k Rampak?
 
If you have or would then please put me down for 1 (or 2 if possible).  
 
I know Peter TheSourcerer had them listed on his price list (Nov 2005) and was very helpful sourcing a 'power adaptor connector' for the USB Comms Link you made.
 
Sincerely and in good faith
Martin
olivierg
active Member




   


Posts: 34
Re: Copy of Rampak 32K
« Reply #6 on: Oct 7th, 2017, 10:17pm »
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Hi Martin,
 
I dont have the schematic of 256K Rampak, i can create by reverse engineering, but i have found this on eBay and is many expensive.
http://www.befr.ebay.be/itm/Psion-Organiser-II-256K-RAMPACK-very-rare/20 2074472082?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649
 
I have create the schematic for share and help (and fun   ) the community of Organiser II, is not for win many money (That's my way of looking at things, but I understand that other people want to live on this, i create other hardware for old computer (ATARI ST) in same way), but i can pay 100£ for after sale 2 pcs. But now if many user request i can pay for this, but you need wait probably 2 months.
 
I have send message to TheSourcerer, but i have not time for this. The USB version can easy replace the original PCB just cut for miniUSB connector.
 
Thanks
Olivier
« Last Edit: Oct 7th, 2017, 10:29pm by olivierg »
MartinReid
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Posts: 78
Re: Copy of Rampak 32K
« Reply #7 on: Oct 8th, 2017, 2:39pm »
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Dear Olivier
 
Thank you for the reply. I can appreciate you not wanting to pay such a high price for an existing Rampak.
 
Perhaps some other forum member has the schematic or knows where we can find one.
 
If a forum member has a 256k Rampak could it be 'reverse engineered' without damaging it? If so maybe a member has one that could be used.
 
Anyway this could be a very exciting development.
 
Sincerely and in good faith
Martin
jaap
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Re: Copy of Rampak 32K
« Reply #8 on: Oct 8th, 2017, 2:41pm »
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Hi Olivier,
If you do (eventually) make a 256k rampak and put them up for sale at 50 Euro or less, I will definitely buy one. So that's one guaranteed customer already .

Jaap Scherphuis
https://www.jaapsch.net/psion/
thesourcerer
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Posts: 126
Re: Copy of Rampak 32K
« Reply #9 on: Oct 8th, 2017, 9:22pm »
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I’ll second that and probably buy a quantity!
Raymond
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Posts: 24
Re: Copy of Rampak 32K
« Reply #10 on: Oct 9th, 2017, 9:16am »
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Me too Please
Mikesan
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Posts: 217
Re: Copy of Rampak 32K
« Reply #11 on: Oct 9th, 2017, 12:26pm »
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Ka-ching!  One for me too, please!
 
It looks as if you'll be dragged, kicking and screaming into the CEO seat of your own large electronics company.  
« Last Edit: Oct 9th, 2017, 12:27pm by Mikesan »
olivierg
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Posts: 34
Re: Copy of Rampak 32K
« Reply #12 on: Oct 9th, 2017, 6:01pm »
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OK, i have ordered now the Rampak 256K.
 
I post next week the estimate price.
 
Thanks
Olivier
 
 
 
MartinReid
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Re: Copy of Rampak 32K
« Reply #13 on: Oct 9th, 2017, 6:41pm »
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That is great news, where are you getting it from?
 
I'm watching with interest
Martin
olivierg
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Posts: 34
Re: Copy of Rampak 32K
« Reply #14 on: Oct 9th, 2017, 7:47pm »
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Belgium.
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