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. >> > >> > >> > >
