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%2Fdigilan
>>>>der.libero.it%2Frar2k%2FTRS80%2FMemory24k.html&data=02%7C01%7C%7C048c022
>>>>979894132d34008d58a9a0491%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C6
>>>>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%2Fphotos
>>>>.app.goo.gl%2FZQle2id7AMWdX2bC3&data=02%7C01%7C%7C048c022979894132d34008
>>>>d58a9a0491%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C6365673164553732
>>>>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%2Fw
>>>>>>>>>ww.ebay.com%2Fitm%2F1-TOSHIBA-TC5565PL-15-64K-8Kx8-SRAM-CMOS-STATIC
>>>>>>>>>-RA&data=02%7C01%7C%7C048c022979894132d34008d58a9a0491%7C84df9e7fe9
>>>>>>>>>f640afb435aaaaaaaaaaaa%7C1%7C0%7C636567316455373249&sdata=11PwB0A2j
>>>>>>>>>z5EIlgU2HQcPAEA7LwIMWh28jGAdm2trv0%3D&reserved=0
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>M-5V-150NS-28-PIN-PDIP/321974484773?hash=item4af72cbf25:g:ldEAAOSwG
>>>>>>>>>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%2Fww
>>>>>>>>w.ebay.com%2Fitm%2F1-TOSHIBA-TC5565PL-15-64K-8Kx8-SRAM-CMOS-STATIC-R
>>>>>>>>A&data=02%7C01%7C%7C048c022979894132d34008d58a9a0491%7C84df9e7fe9f64
>>>>>>>>0afb435aaaaaaaaaaaa%7C1%7C0%7C636567316455373249&sdata=11PwB0A2jz5EI
>>>>>>>>lgU2HQcPAEA7LwIMWh28jGAdm2trv0%3D&reserved=0
>>>>>>>>
>>>>>>>>
>>>>>>>>M-5V-150NS-28-PIN-PDIP/321974484773?hash=item4af72cbf25:g:ldEAAOSwGo
>>>>>>>>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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