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User Forum >> General >> FlashPak 256K
(Message started by: olivierg on Oct 19th, 2017, 10:57pm)

Title: FlashPak 256K
Post by olivierg on Oct 19th, 2017, 10:57pm
Hi All,

I have create the schematic of FlashPak 256K:
http://www.gossuin.be/images/psion/FlashPak-256K.pdf

I have small question about flashpak:
1) The driver is builtin the psion or Flashpak ?
2) it's possible to copy the driver by serial ?
3) i try to format, but i have error: ERROR DEVICE MISSING and not format, but i can read/write file, are you explanation ?
4) i see on schematic on my version 3 jumpers, why ?
5) What the maximum capacity psion support ?


Thanks
Olivier


Title: Re: FlashPak 256K
Post by thesourcerer on Oct 20th, 2017, 12:08am
The 256k Flash Datapack has an inbuilt driver (7132k for v19, F8) on the Flash Datapack.
It can be copied by serial (see Jaap’s website).
It can only be formatted by another Flash Datapack (WARNING EARLIER VERSIONS CAN CAUSE CORRUPTION), by the EPROM version of the driver, or by serial Comms Link download. Having said that I often find that the ERROR message occurs the first time a Flash Datapack is inserted in the organiser,and simply pressing the ON/CLEAR button resolves the problem.
4) Don’t understand!
5) Not sure of your question, but a blank formatted pack shows 255009 bytes free.
Hope this is useful, but I am no expert!

Title: Re: FlashPak 256K
Post by thesourcerer on Oct 20th, 2017, 12:15am
Just checked, Jaap has the driver listed as FDrive 1.9 on his website.
(PC software).
Never used it but I’m sure it is OK.

Title: Re: FlashPak 256K
Post by thesourcerer on Oct 20th, 2017, 12:19am
My apologies for the gobbledegook that comes from putting an apostrophe in my text. Blame it on my iPad!

Title: Re: FlashPak 256K
Post by olivierg on Oct 20th, 2017, 2:12am
ok, I saw on the site the driver.

Questions 4 and 5 are related:
for Q5: What the maximum size capacity FlashPak or RamPak the psion support, 512 1M 2M or more ?
For Q4: in schematic of Flashpak, i have 3 jumpers setting (probably first version of the flashpak).
In case 256K the jumper 1 is set.
The pin 30 on Flash ic (28F010) is not connect inside but connect in schematic. On the 28F020 (double capacity of 28F010) it's used for A17, it's strange maybe i can change the chip and convert the FlashPak to 512K ?
But, the driver can drive this size ?

Thanks
Olivier

Title: Re: FlashPak 256K
Post by jaap on Oct 20th, 2017, 6:43am
I agree that the jumpers are used for configuring the size of the pack according to the memory chips used. The jumpers control which of the two memory chips is active when the Psion sets the segment of the address it wants to read/write.

On a 128K flashpack one of the memory chips is missing, so in that case the chip should always be selected. Presumably this means all the jumpers are off so that the chip selection circuit never switches to the missing chip. I remember someone tried simply soldering an extra chip into a 128K flashpak, but that didn't work because it was never selected.

On a 256K flashpack jumper 1 is set. Then bit 3 of the segment register controls which chip is active. So segments 0-7 go to one chip, and segments 8-15 to the other.

As you noticed, the wiring is there to allow for larger memory chips. As far as I'm aware, these chips were never used. If you used two 28F020 chips, and set only jumper 2, it should give a 512K pack. Then bit 4 of the segment register controls which chip is active. Bits 0-3 of the segment register go to both chips as the top address lines. So segments 0-15 go to one chip, and segments 16-31 to the other. Of course you could also use just one of those chips to create an alternative 256K pack if you switch off all the jumpers.

I expect the flash driver can handle a 512K pack. I have not looked at the driver code, but do know how the Psion rom handles packs and think that the flash driver uses the same method. What it does is write a particular value to address 0 of the pack, and then read subsequent addresses (to make sure the pack is empty) until it sees that value again. That means that the address has wrapped around back to 0 and the whole pack has been read exactly once. That is how the pack is "sized", i.e. how its size is determined. Only then does the Psion write the rest of the pack header to prepare the pack for use.

I think the flash driver does the same, so a larger flashpak should just work.

Title: Re: FlashPak 256K
Post by olivierg on Oct 20th, 2017, 8:10am
Thanks to reply jaap.

I have ordered the 28F020 for test.

Thanks
Olivier

Title: Re: FlashPak 256K
Post by olivierg on Jan 26th, 2018, 8:21am
Hi All,

The copy of flashpack works.
The first test in 256K (254720) pass the jaap test.
I have launch test in 512K (516864) the format and write with jaap software test work. The check is long.

Thanks
Olivier

Title: Re: FlashPak 256K
Post by olivierg on Jan 30th, 2018, 10:31pm
Hi All,

i have launch the small production, the read/write test is long.
Now is on stock.

Thanks
Olivier

Title: Re: FlashPak 256K
Post by Nick Kostelidis on Dec 13th, 2018, 6:54pm
Hi. Is there any possibility to be created an 1MB flash data pack?



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