Brian, Gotcha. What would you clean it off with? Acetone? Ethanol? De-Oxit?
On Mon, May 7, 2018 at 10:35 AM, Brian White <[email protected]> wrote: > He meant that after building, the flux must be washed off. You can't leave > the dried flux in there, even if it is "no-clean" flux, because the flux > will leak enough current to matter. > > On Mon, May 7, 2018, 10:42 AM Diggy Dude <[email protected]> > wrote: > >> To make sure I understand: >> >> Clean all pads and leads with flux.Will a flux pen suffice, or should >> liquid flux be used? >> >> What specific 74HC and SRAM devices do you use? >> >> On Mon, May 7, 2018 at 2:45 AM, Francesco Messineo < >> [email protected]> wrote: >> >>> On Mon, May 7, 2018 at 9:08 AM, Diggy Dude <[email protected]> >>> wrote: >>> > Thanks, Fugu! >>> > >>> > So the modern solution is a single SRAM and capacitor on a SOIC-to-DIP >>> > breakout? What's the RAM chip they're using? >>> >>> and a logic chip (there're a few different approaches here) to combine >>> the separate chip selects to a couple of addresses and a single select >>> signal. My own version of the circuit uses the fewest ports possible >>> (at least if nobody comes up with a different approach I couldn't >>> think of). >>> The RAM chip must be a CMOS static ram, 8kx8 and with low power >>> standby (not all have this feature). The original 8k modules were >>> specified for 4 uA max standby current, that allows the standby >>> battery to keep the RAM content for over a month. Usually the suitable >>> chips have L or LL in the part number, but you better check the >>> datasheet for the fine details. Most of the suitable RAM chips have a >>> measured standby current of 0.1 uA (often less) at 3.3V if the chip >>> select are driven with the correct voltages. At these current levels, >>> cleaning the soldering flux is a must. I've measured up to 15 uA of >>> standby current on badly cleaned modules. YMMV. >>> Glue logic *must* be 74HC family, it has a suitable current draw at >>> 3.3V standby and suitable speed. In one case I've used 74AHC and it >>> worked well too. >>> >>> > >>> > -- Jim >>> > >>> > On Sun, May 6, 2018 at 10:29 PM, Fugu ME100 <[email protected]> >>> wrote: >>> >> >>> >> You could try >>> >> https://www.arcadeshopper.com/wp/?page_id=11#!/8k-RAM- >>> module-for-Model-100/p/104430801/category=28313042 >>> >> >>> >> They have the M100 modules if you want to buy. >>> >> >>> >> If you want to build your own there are PCBs on OSH Park for surface >>> mount >>> >> and DIP versions. >>> >> >>> >> No need for any pillaging :) >>> >> >>> >> From: M100 <[email protected]> on behalf of Diggy >>> Dude >>> >> <[email protected]> >>> >> Reply-To: <[email protected]> >>> >> Date: Sunday, May 6, 2018 at 8:13 PM >>> >> To: <[email protected]> >>> >> Subject: [M100] 8K RAM module >>> >> >>> >> Anyone know where I can get an additional 8K for my 24K M100 without >>> >> pillaging another M100? Let's face it: if I got another M100, I'd be >>> >> inclined to leave it intact. >>> > >>> > >>> >> >>
