On Thu, Mar 15, 2018 at 8:57 PM, Fugu ME100 <[email protected]> wrote:
> So this uses a test set up rather than the laptop?  That makes it much
> easier to to work on :)

I decided to make an external test setup after I've nearly ruined the
RAM socket in my M10.
I could roughly estimate the current consumption by looking at the
Voltage drop on the backup battery when a module was inserted.

>
> I built a T200 RAM module using the FET method which allows the CS- lines
> to pull up nearly to Vdd,  I was just curious as to how well they were
> working.
>
> On 15/3/18, 12:23 PM, "M100 on behalf of Francesco Messineo"
> <[email protected] on behalf of
> [email protected]> wrote:
>
>>On Thu, Mar 15, 2018 at 8:13 PM, Fugu ME100 <[email protected]> wrote:
>>> Hi Frank
>>>
>>> How did you perform the current drain tests?
>>
>>I've left one test module with the fully charged battery of my M10.
>>It drained the battery in a little more than a day. It was not an
>>intended test the first time, it was a design error on my side.
>>I then made a test setup to measure the current drain on a 3.3V
>>standby condition and my first (wrong) logic design was allowing the
>>ram chip drain about 1 mA instead of the correct 1 uA (or usually
>>less) when the chip select(s) are held at the correct level (usually
>>between 0.2V from the opposite rail of the active level).
>>I then changed design.
>>I've made more than 70 8K modules so far, all have been tested for < 4
>>uA current draw in standby conditions (most of the times, they end
>>under 0.1uA which is my test setup measure limit).
>>
>>
>>>
>>> On 15/3/18, 10:27 AM, "M100 on behalf of Francesco Messineo"
>>> <[email protected] on behalf of
>>> [email protected]> wrote:
>>>
>>>>On Thu, Mar 15, 2018 at 6:08 PM, Mike Stein <[email protected]> wrote:
>>>>> Yeah, there are a number of ways to deal with the non-standard RAM
>>>>>modules
>>>>> in an M100; the pin spacing of the modules is .75 instead of the
>>>>>standard
>>>>> .60, so you will probably have to make a little adapter board in any
>>>>>case.
>>>>>
>>>>spacing is actually 700 mils
>>>>
>>>>> A self-contained module has to combine the four discrete chip selects
>>>>>into
>>>>> one, and also re-encode them into the binary upper two addresses.
>>>>>There
>>>>>are
>>>>> various ways of doing that and I have some of the commercial circuits
>>>>> somewhere but can't find them at the moment.
>>>>>
>>>>> One way would be a priority encoder as Fugu suggests. His 32K idea is
>>>>>clever
>>>>> and you could just used diodes to combine the chip selects; as a
>>>>>matter
>>>>>of
>>>>> fact you can also use an 8K chip and use diodes for the encoding
>>>>>instead of
>>>>> the encoder IC.
>>>>
>>>>A word of warning about using diodes to combine the selects: all the
>>>>low power cmos rams need close to Vdd or Vss levels on the select to
>>>>have the lowest current consumption when in sleep mode (Vdd circa 3V
>>>>inside the M100).
>>>>If the ram chip doesn't go in the correct standby mode, the internal
>>>>battery of the M100 is drained in about one day instead of the usual
>>>>one month (tests done in my Olivetti M10 several times).
>>>>
>>>>
>>>>Frank
>>>>>
>>>>> ----- Original Message -----
>>>>> From: Fugu ME100
>>>>> To: [email protected]
>>>>> Sent: Wednesday, March 14, 2018 5:14 PM
>>>>> Subject: Re: [M100] 8K RAM Chip
>>>>>
>>>>> If you did not want to use the Libero method you could use a 74HC148
>>>>>(or
>>>>> similar) 8 to 3 line priority decoder and put the 4 CSx- lines into
>>>>>the
>>>>> upper or lower 4 inputs of the Œ148. That would recreate 2 address
>>>>>lines and
>>>>> a new CS- for the 8Kx8 SRAM.  It could all mount on a proto-board and
>>>>>not
>>>>> require any 'soldering to' the M100 :)  I would guess the NEC board
>>>>>uses a
>>>>> similar method but with an HC149 8-to-8 line priority encoder.
>>>>>
>>>>> Alternatively use a 32Kx8 SRAM and waste 3/4 of the space, but it
>>>>>would
>>>>> still need the CSx- lines ANDed to generate the SRAM CS-. Again no
>>>>>soldering
>>>>> on the M100 required.
>>>>>
>>>>>
>>>>>
>>>>> From: M100 <[email protected]> on behalf of Mike Stein
>>>>> <[email protected]>
>>>>> Reply-To: <[email protected]>
>>>>> Date: Wednesday, March 14, 2018 at 12:19 PM
>>>>> To: <[email protected]>
>>>>> Subject: Re: [M100] 8K RAM Chip
>>>>>
>>>>> It needs more than just remapping the signals; the required upper two
>>>>> address lines are not available on the sockets so you either need to
>>>>>add
>>>>> logic to recreate them or modify the main board.
>>>>>
>>>>> m
>>>>>
>>>>> ----- Original Message -----
>>>>> From: Gregory McGill
>>>>> To: [email protected]
>>>>> Sent: Wednesday, March 14, 2018 1:22 PM
>>>>> Subject: Re: [M100] 8K RAM Chip
>>>>>
>>>>> thanks! It seems like we should be able to use the 8x8 chip from the
>>>>>102
>>>>> with some kludging of lines.. they are pretty close..
>>>>>
>>>>> Greg
>>>>>
>>>>> On Wed, Mar 14, 2018 at 10:08 AM, Brian White <[email protected]>
>>>>>wrote:
>>>>>>
>>>>>> There are at least a few different "build your own ram upgrade"
>>>>>>articles
>>>>>> on club100 and other archives of old forum posts, and in magazines
>>>>>>too
>>>>>>I
>>>>>> think but those are hard to search.
>>>>>>
>>>>>> Here's one that is not one of the old original ones I was thinking
>>>>>>of,
>>>>>>but
>>>>>> looks ok.
>>>>>>
>>>>>>
>>>>>>https://nam03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdigil
>>>>>>an
>>>>>>der.libero.it%2Frar2k%2FTRS80%2FMemory24k.html&data=02%7C01%7C%7C048c0
>>>>>>22
>>>>>>979894132d34008d58a9a0491%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7
>>>>>>C6
>>>>>>36567316455373249&sdata=M401o8EYP5VKZbt6sd4xlFFLtEzMNxzZypxq02jdHtA%3D
>>>>>>&r
>>>>>>eserved=0
>>>>>>
>>>>>> I have some NEC modules that work that I assume must have originally
>>>>>>been
>>>>>> meant for nec 8201a. They are a little pcb with a single ram chip and
>>>>>>an
>>>>>> additional chip probably a decoder of some sort to consume 4
>>>>>>chip-enable
>>>>>> lines. I could take some photos of it and maybe it's circuit could be
>>>>>> reverse engineered from that.
>>>>>>
>>>>>>
>>>>>>https://nam03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fphot
>>>>>>os
>>>>>>.app.goo.gl%2FZQle2id7AMWdX2bC3&data=02%7C01%7C%7C048c022979894132d340
>>>>>>08
>>>>>>d58a9a0491%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C63656731645537
>>>>>>32
>>>>>>49&sdata=U1zwRxS%2BqcGGwPwxZaDIUlpa3LnVMkq5gj5%2F5NZFThU%3D&reserved=0
>>>>>>
>>>>>> Another option is QUAD, which is a thing that installs in the bus
>>>>>>socket
>>>>>> and displaces the internal ram with it's own full 32K, plus 3 more
>>>>>>banks of
>>>>>> 32K that you can switch between. Although you can't get a quad right
>>>>>>now.
>>>>>> Steven Adolph is testing his latest revision of the design and it's
>>>>>>in
>>>>>> between right now. He found problems with the old version and so
>>>>>>removed it
>>>>>> from oshpark, and th new version is not yet verified.
>>>>>>
>>>>>> But assuming that comes along sooner or later, that would upgrade you
>>>>>>to
>>>>>> 32K the same as if you had installed all 4 possible modules inside.
>>>>>>
>>>>>> --
>>>>>> bkw
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Wed, Mar 14, 2018, 11:14 AM Gregory McGill
>>>>>><[email protected]>
>>>>>> wrote:
>>>>>>>
>>>>>>> ok is there a source for the 100 chips? or a pcb?
>>>>>>>
>>>>>>> Greg
>>>>>>>
>>>>>>> On Wed, Mar 14, 2018 at 12:02 AM, Fugu ME100 <[email protected]>
>>>>>>>wrote:
>>>>>>>>
>>>>>>>> Just the 102,  it uses a standard pin out. The 100 uses a special
>>>>>>>>RAM
>>>>>>>> module.
>>>>>>>>
>>>>>>>> From: M100 <[email protected]> on behalf of Gregory
>>>>>>>> McGill <[email protected]>
>>>>>>>> Reply-To: <[email protected]>
>>>>>>>> Date: Tuesday, March 13, 2018 at 10:58 PM
>>>>>>>> To: <[email protected]>
>>>>>>>> Subject: Re: [M100] 8K RAM Chip
>>>>>>>>
>>>>>>>> oh wait these are 32x8 :)  are these ones on ebay for the 100 or
>>>>>>>>102? or
>>>>>>>> both?
>>>>>>>>
>>>>>>>> Greg
>>>>>>>>
>>>>>>>> On Fri, Mar 9, 2018 at 7:33 PM, Gregory McGill
>>>>>>>><[email protected]>
>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>> if you have the pinouts I have a bunch of 8x8 srams around for
>>>>>>>>>TI99
>>>>>>>>> projects
>>>>>>>>>
>>>>>>>>> Greg
>>>>>>>>>
>>>>>>>>> On Fri, Mar 9, 2018 at 6:11 PM, Ken Pettit <[email protected]>
>>>>>>>>>wrote:
>>>>>>>>>>
>>>>>>>>>> Ahh, I see now the original email stated 102.  So yeah, those
>>>>>>>>>>will
>>>>>>>>>> work.
>>>>>>>>>>
>>>>>>>>>> Ken
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On 3/9/18 6:09 PM, Fugu ME100 wrote:
>>>>>>>>>>>
>>>>>>>>>>> More if it was R/S :)
>>>>>>>>>>>
>>>>>>>>>>> This is the one
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>https://nam03.safelinks.protection.outlook.com/?url=https%3A%2F%2
>>>>>>>>>>>Fw
>>>>>>>>>>>ww.ebay.com%2Fitm%2F1-TOSHIBA-TC5565PL-15-64K-8Kx8-SRAM-CMOS-STAT
>>>>>>>>>>>IC
>>>>>>>>>>>-RA&data=02%7C01%7C%7C048c022979894132d34008d58a9a0491%7C84df9e7f
>>>>>>>>>>>e9
>>>>>>>>>>>f640afb435aaaaaaaaaaaa%7C1%7C0%7C636567316455373249&sdata=11PwB0A
>>>>>>>>>>>2j
>>>>>>>>>>>z5EIlgU2HQcPAEA7LwIMWh28jGAdm2trv0%3D&reserved=0
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>M-5V-150NS-28-PIN-PDIP/321974484773?hash=item4af72cbf25:g:ldEAAOS
>>>>>>>>>>>wG
>>>>>>>>>>>otWlWd9
>>>>>>>>>>> you mean?
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On 9/3/18, 6:07 PM, "M100 on behalf of Peter Vollan"
>>>>>>>>>>> <[email protected] on behalf of
>>>>>>>>>>>[email protected]>
>>>>>>>>>>> wrote:
>>>>>>>>>>>
>>>>>>>>>>>> Wow, a quick check reveals a 8kX8 SRAM on ebay for $3. Didn't
>>>>>>>>>>>>those
>>>>>>>>>>>> "memory modules" cost about $30?
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> On 9 March 2018 at 17:57, Chris Kmiec <[email protected]>
>>>>>>>>>>>>wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>> Great, I'll go looking on the intrawebs :)
>>>>>>>>>>>>>
>>>>>>>>>>>>> You don't happen to have another REX, do you? :)
>>>>>>>>>>>>>
>>>>>>>>>>>>> Chris
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Fri, Mar 9, 2018 at 7:01 PM, Fugu ME100
>>>>>>>>>>>>><[email protected]>
>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The chips are available they are standard 8Kx8 SRAM.  Should
>>>>>>>>>>>>>>be
>>>>>>>>>>>>>> able to
>>>>>>>>>>>>>> find some on line.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Unfortunately the QUAD is only for the Model 100, it will not
>>>>>>>>>>>>>>fit
>>>>>>>>>>>>>> the
>>>>>>>>>>>>>> 102.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Congratulations on your new addition :)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> From: M100 <[email protected]> on behalf of
>>>>>>>>>>>>>>Chris
>>>>>>>>>>>>>> Kmiec
>>>>>>>>>>>>>> <[email protected]>
>>>>>>>>>>>>>> Reply-To: <[email protected]>
>>>>>>>>>>>>>> Date: Friday, March 9, 2018 at 4:33 PM
>>>>>>>>>>>>>> To: <[email protected]>
>>>>>>>>>>>>>> Subject: [M100] 8K RAM Chip
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Are these available anywhere, or do I have to find a donor
>>>>>>>>>>>>>>system?
>>>>>>>>>>>>>> Just
>>>>>>>>>>>>>> got a like-new 102, but no memory expansion.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I'm assuming QUAD is no longer being made/sold?
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Thanks!
>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>> On Mar 14, 2018 11:14 AM, "Gregory McGill" <[email protected]>
>>>>>> wrote:
>>>>>>
>>>>>> ok is there a source for the 100 chips? or a pcb?
>>>>>>
>>>>>> Greg
>>>>>>
>>>>>> On Wed, Mar 14, 2018 at 12:02 AM, Fugu ME100 <[email protected]>
>>>>>>wrote:
>>>>>>>
>>>>>>> Just the 102,  it uses a standard pin out. The 100 uses a special
>>>>>>>RAM
>>>>>>> module.
>>>>>>>
>>>>>>> From: M100 <[email protected]> on behalf of Gregory
>>>>>>> McGill <[email protected]>
>>>>>>> Reply-To: <[email protected]>
>>>>>>> Date: Tuesday, March 13, 2018 at 10:58 PM
>>>>>>> To: <[email protected]>
>>>>>>> Subject: Re: [M100] 8K RAM Chip
>>>>>>>
>>>>>>> oh wait these are 32x8 :)  are these ones on ebay for the 100 or
>>>>>>>102?
>>>>>>>or
>>>>>>> both?
>>>>>>>
>>>>>>> Greg
>>>>>>>
>>>>>>> On Fri, Mar 9, 2018 at 7:33 PM, Gregory McGill
>>>>>>><[email protected]>
>>>>>>> wrote:
>>>>>>>>
>>>>>>>> if you have the pinouts I have a bunch of 8x8 srams around for TI99
>>>>>>>> projects
>>>>>>>>
>>>>>>>> Greg
>>>>>>>>
>>>>>>>> On Fri, Mar 9, 2018 at 6:11 PM, Ken Pettit <[email protected]>
>>>>>>>>wrote:
>>>>>>>>>
>>>>>>>>> Ahh, I see now the original email stated 102.  So yeah, those will
>>>>>>>>> work.
>>>>>>>>>
>>>>>>>>> Ken
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 3/9/18 6:09 PM, Fugu ME100 wrote:
>>>>>>>>>>
>>>>>>>>>> More if it was R/S :)
>>>>>>>>>>
>>>>>>>>>> This is the one
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>https://nam03.safelinks.protection.outlook.com/?url=https%3A%2F%2F
>>>>>>>>>>ww
>>>>>>>>>>w.ebay.com%2Fitm%2F1-TOSHIBA-TC5565PL-15-64K-8Kx8-SRAM-CMOS-STATIC
>>>>>>>>>>-R
>>>>>>>>>>A&data=02%7C01%7C%7C048c022979894132d34008d58a9a0491%7C84df9e7fe9f
>>>>>>>>>>64
>>>>>>>>>>0afb435aaaaaaaaaaaa%7C1%7C0%7C636567316455373249&sdata=11PwB0A2jz5
>>>>>>>>>>EI
>>>>>>>>>>lgU2HQcPAEA7LwIMWh28jGAdm2trv0%3D&reserved=0
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>M-5V-150NS-28-PIN-PDIP/321974484773?hash=item4af72cbf25:g:ldEAAOSw
>>>>>>>>>>Go
>>>>>>>>>>tWlWd9
>>>>>>>>>> you mean?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On 9/3/18, 6:07 PM, "M100 on behalf of Peter Vollan"
>>>>>>>>>> <[email protected] on behalf of
>>>>>>>>>>[email protected]>
>>>>>>>>>> wrote:
>>>>>>>>>>
>>>>>>>>>>> Wow, a quick check reveals a 8kX8 SRAM on ebay for $3. Didn't
>>>>>>>>>>>those
>>>>>>>>>>> "memory modules" cost about $30?
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On 9 March 2018 at 17:57, Chris Kmiec <[email protected]> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>> Great, I'll go looking on the intrawebs :)
>>>>>>>>>>>>
>>>>>>>>>>>> You don't happen to have another REX, do you? :)
>>>>>>>>>>>>
>>>>>>>>>>>> Chris
>>>>>>>>>>>>
>>>>>>>>>>>> On Fri, Mar 9, 2018 at 7:01 PM, Fugu ME100
>>>>>>>>>>>><[email protected]>
>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>> The chips are available they are standard 8Kx8 SRAM.  Should
>>>>>>>>>>>>>be
>>>>>>>>>>>>> able to
>>>>>>>>>>>>> find some on line.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Unfortunately the QUAD is only for the Model 100, it will not
>>>>>>>>>>>>>fit
>>>>>>>>>>>>> the
>>>>>>>>>>>>> 102.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Congratulations on your new addition :)
>>>>>>>>>>>>>
>>>>>>>>>>>>> From: M100 <[email protected]> on behalf of
>>>>>>>>>>>>>Chris
>>>>>>>>>>>>> Kmiec
>>>>>>>>>>>>> <[email protected]>
>>>>>>>>>>>>> Reply-To: <[email protected]>
>>>>>>>>>>>>> Date: Friday, March 9, 2018 at 4:33 PM
>>>>>>>>>>>>> To: <[email protected]>
>>>>>>>>>>>>> Subject: [M100] 8K RAM Chip
>>>>>>>>>>>>>
>>>>>>>>>>>>> Are these available anywhere, or do I have to find a donor
>>>>>>>>>>>>>system?
>>>>>>>>>>>>> Just
>>>>>>>>>>>>> got a like-new 102, but no memory expansion.
>>>>>>>>>>>>>
>>>>>>>>>>>>> I'm assuming QUAD is no longer being made/sold?
>>>>>>>>>>>>>
>>>>>>>>>>>>> Thanks!
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>
>>>
>
>

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