Re: DS12887 pcb substitute with battery

Hi Alan > What are you talking about? > > https://www.digikey.com/product-detail/en/maxim-integrated/DS12885/DS12885-ND/1196867 Thank you for your input, however a DS12885 is not a DS1285 (and neither a DS12887/A is a DS1287/A), and I did explain why I only consider an exact replacement

Re: DS12887 pcb substitute with battery

What are you talking about? https://www.digikey.com/product-detail/en/maxim-integrated/DS12885/DS12885-ND/1196867 -Alan On 2017-11-21 14:16, Maciej W. Rozycki via cctech wrote: On Mon, 13 Nov 2017, systems_glitch wrote: Good stuff! I recently designed a module to build new DS1287 and

Re: DS12887 pcb substitute with battery

On Mon, 13 Nov 2017, systems_glitch wrote: > Good stuff! I recently designed a module to build new DS1287 and DS12887 > modules from the bare DS1285 and DS12885 ICs: > > https://imgur.com/a/cgKm5 Nice! That wouldn't solve my problem though, given the apparent unavailability of DS1285 chips

Re: DS12887 pcb substitute with battery

Good stuff! I recently designed a module to build new DS1287 and DS12887 modules from the bare DS1285 and DS12885 ICs: https://imgur.com/a/cgKm5 Just did a small run of 100 boards with the GW-12887-1 part number (they of course work with the DS1285, though the number would be misleading). It

Re: DS12887 pcb substitute with battery

Hi Chuck, It's taken me a little while to respond to this one, however certain matters do need time to develop. On Sun, 22 Jan 2017, Chuck Guzis wrote: > On 01/22/2017 01:49 PM, Maciej W. Rozycki wrote: > > > A problem with reworking is there is sometimes very little clearance > >

Re: DS12887 pcb substitute with battery

On 01/23/2017 09:04 AM, Jon Elson wrote: > Well, it doesn't really matter. If you can find one of the "really > old" ones, the battery can be replaced and you are good for 5 years > or so. There must be TONS of these old clock/RAM chips out there, and > somebody must have saved a few. Probably

Re: DS12887 pcb substitute with battery

On 01/23/2017 04:57 AM, allison wrote: On 01/22/2017 02:46 PM, Chuck Guzis wrote: On 01/22/2017 10:57 AM, allison wrote: I don't know about most people but this solution has been around for decades. I locate the battery on the failed part with a small magnet, then grind the epoxy down to it

Re: DS12887 pcb substitute with battery

On 01/22/2017 02:46 PM, Chuck Guzis wrote: > On 01/22/2017 10:57 AM, allison wrote: >> I don't know about most people but this solution has been around for >> decades. >> >> I locate the battery on the failed part with a small magnet, then >> grind the epoxy down to it then pick it out with a

Re: DS12887 pcb substitute with battery

On 01/22/2017 01:49 PM, Maciej W. Rozycki wrote: > A problem with reworking is there is sometimes very little clearance > available, so any modification has to be made in a clever way or you > risk a short-circuit. For example in DECstation 5000 systems their > DS1287 chip is located in the

Re: DS12887 pcb substitute with battery

On Sun, 22 Jan 2017, Chuck Guzis wrote: > It's worth noting that the original post was about fabricating a > replacement using the DS12885A RTC chip. However, most old PCs used the > DS1285 RTC (inside of a DS1287 module). The DS12885A is supposed to be > drop-in compatible with the DS1285,

DS12887 pcb substitute with battery

I was hoping someone would make a M48Txx version for the old Suns etc. Richard Sheppard

Re: DS12887 pcb substitute with battery

On Sun, Jan 22, 2017 at 5:16 PM, Jon Elson wrote: > On 01/22/2017 10:07 AM, Ali wrote: >> >> Al, >> I thought the problem with switching these chips was that part of the ROM >> code was embedded in them? I.e. it isn't just an issue of battery? Am I >> wrong? If I am then

Re: DS12887 pcb substitute with battery

On 01/22/2017 10:57 AM, allison wrote: > I don't know about most people but this solution has been around for > decades. > > I locate the battery on the failed part with a small magnet, then > grind the epoxy down to it then pick it out with a sharp pointed > tool. Once I expose the connection

Re: DS12887 pcb substitute with battery

> Posts" <cctalk@classiccmp.org> > Subject: Re: DS12887 pcb substitute with battery > > On 01/22/2017 10:07 AM, Ali wrote: >> Al, >> I thought the problem with switching these chips was that part of the ROM >> code was embedded in them? I.e. it isn't just an

Re: DS12887 pcb substitute with battery

From: Jon Elson <el...@pico-systems.com> Date: 1/22/17 9:16 AM (GMT-08:00) To: gene...@classiccmp.org, "discuss...@classiccmp.org:On-Topic and Off-Topic Posts" <cctalk@classiccmp.org> Subject: Re: DS12887 pcb substitute with battery On 01/22/2017 10:07 AM, Ali wr

Re: DS12887 pcb substitute with battery

On 01/22/2017 10:07 AM, Ali wrote: Al, I thought the problem with switching these chips was that part of the ROM code was embedded in them? I.e. it isn't just an issue of battery? Am I wrong? If I am then why not use one of the replacement chips that are available? These don't have a lot of

RE: DS12887 pcb substitute with battery

<a...@bitsavers.org> Date: 1/21/17 12:12 PM (GMT-08:00) To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk@classiccmp.org> Subject: DS12887 pcb substitute with battery someone just pointed this out on vcfed https://oshpark.com/shared_projects/qyNfzAMf

Re: DS12887 pcb substitute with battery

On 01/21/2017 12:12 PM, Al Kossow wrote: > someone just pointed this out on vcfed > > https://oshpark.com/shared_projects/qyNfzAMf The DS12887 still comes in PDIP; no need to go to a PCB and an SOIC, is there? --Chuck

DS12887 pcb substitute with battery

someone just pointed this out on vcfed https://oshpark.com/shared_projects/qyNfzAMf