guilford@csv.rpi.edu (Jim Guilford) (09/01/87)
[] I recently built "JTIME: a Real-Time Clock for the Amiga" by Micharl Keryan. It is a clock/calendar that plugs into the second joystick port. The plans and description came on an amiga disk (I forget where I got the original from. It might have been a fish disk or a BBS, but I can't recall). It is based around the RTC58321 clock/calendar chip by SaRonix. I ordered the chip from Jameco, who give the part number as MSM58321RS. After wiring up a small circuit board, I inspected it and tested it. It didn't work. I pulled the chips, did some more testing, and found a short between two wires, I fixed that, repopulated the board, and plugged it in. I found that I could read and write the date/time with no problem, but that the time was not advancing. It seemed to be doing a good job of emulating a battery backed up slice of ram! I am looking for help and/or suggestions on what may be wrong. Here are my observations. I don't think I trashed any of the chips as I can successfully read and write to the clock/calandar. My schematics give the 58321 five unconnected pins: 10, 11, 12, 14, and 15. My voltmeter gives one of the pins (I can't recall which, but I think it was 14) either an intermediate level voltage, or a time varying voltage, I can't tell which. I am wondering if some caps or resistors are missing, or whether I'm supposed to feed back a clock signal back into the chip someplace. Unfortunately, I haven't been able to come up with a spec sheet for the chip. I thought that maybe the MSM58321RS might not be a RTC58321, but it seems to work quite well other than counting. This is quite a coincidence unless it is design to clone the RTC, but with some extra features or bugs. The RTC is supposed to have an internal trimed and sealed quartz crystal, and the schematics show no external analog components (e.g. resistors or caps). Does anyone out there in Netland have any clue as to what is going on? The chip is semi-expensive (and Jameco's minimum order is $20), so I don't want to order a new chip and find out that nothing changed. I decided to rough it out and build it myself to save some money. To avoid cluttering the net, I would appreciate it if you would email any replies to me. Of course, if there is enough interest, I will summarize the results to the net. Thanks in advance for any help you can offer me. I am . . . Jim Guilford guilford@csv.rpi.edu or ...seismo!rpics!guilford
mikec@cbmvax.UUCP (Mike Colligon QA) (09/02/87)
To Jim Guilford and anyone else with a similar problem with JTIME or any battery backed up clock for the Amiga 1000. You are not alone! I had exactly the same problem using TIC from Byte-by-Byte. I could save the system time and date to TIC and I could load the time and date from TIC, but the time and date were always the same as when I saved it. Sounds like an strange coincidence that to different products have the same problem. I wonder how close the two designs are? My fix for the problem may not work for you. I put TIC back in the box and said "I'll wait for the A2000!" :-) I'm sorry I have no real solution for the problem. How about some input from other TIC owners and JTIME builders? -- -------------------------------------------------------------------------------- | Michael Colligon uucp: {ihnp4|seismo|caip}!cbmvax!mikec | | Quality Assurance Dept. arpa: cbmvax!mikec@seismo.css.GOV | | Commodore Business Machines or mikec@cbmvax.UUCP@{seismo|harvard} | |------------------------------------------------------------------------------| | "I say we take off; nuke the site from orbit. Its the only way to be sure." | | Corporal Hicks | --------------------------------------------------------------------------------
schein@cbmvax.UUCP (Dan Schein MAGAZINES) (09/03/87)
In article <2290@cbmvax.UUCP> mikec@cbmvax.UUCP (Mike Colligon QA) writes: > >I'm sorry I have no real solution for the problem. How about some input from >other TIC owners and JTIME builders? ^^^ ^^^^^ I have had a TIC since Winter CES (Jan of 87) and it has performed just fine on both of my A1000's, it has also worked fine on 2 A1000's w/Sidecar that I tried it with. I have since updated one of my A1000's with an "INSIDER" 1 Meg memory / battery clock - calander and that also keeps correct time. The TIC is still ticking (ha ha ha) away on my other A1000 just like new. > >-- >| Michael Colligon uucp: {ihnp4|seismo|caip}!cbmvax!mikec | -- +----------------------------------------------------------------------------+ | Commodore Business Machines | | 1200 Wilson Drive uucp: {ihnp4|seismo|caip}!cbmvax!schein | | West Chester, PA 19380 arpa: cbmvax!schein@seismo.css.GOV | | (215) 431-9100 x9542 or schein@cbmvax.UUCP@{seismo|harvard} | +----------------------------------------------------------------------------+ | All spelling mistakes are a result of my efforts to avoid education :-) | +----------------------------------------------------------------------------+ | Quote: Those who worked the hardest Gary Ward - Oklahoma State | | are the last to surrender baseball coach | +----------------------------------------------------------------------------+
grr@cbmvax.UUCP (George Robbins) (09/05/87)
In article <30@rpicsb8> guilford@csv.rpi.edu (Jim Guilford) writes: > [] > > I recently built "JTIME: a Real-Time Clock for the Amiga" by Micharl Keryan. > It is a clock/calendar that plugs into the second joystick port. The plans > and description came on an amiga disk (I forget where I got the original > from. It might have been a fish disk or a BBS, but I can't recall). It is > based around the RTC58321 clock/calendar chip by SaRonix. I ordered the chip > from Jameco, who give the part number as MSM58321RS. > > After wiring up a small circuit board, I inspected it and tested it. It > didn't work. I pulled the chips, did some more testing, and found a short > between two wires, I fixed that, repopulated the board, and plugged it in. I > found that I could read and write the date/time with no problem, but that > the time was not advancing. It seemed to be doing a good job of emulating a > battery backed up slice of ram! I suspect that the RTC58321 is a hybrid package containing an OKI MSM5831 clock chip and a watch crystal, if not a battery. Since the OKI chip you got from Jameco needs an external watch crystal, the board just sits there looking stupid. Solution: check out the JTIME info more carefully and either add a watch crystal or get hold of the saronix part. Sometime the people who cook up these projects get carried away and forget to use least common denominator parts that are easy to find. -- George Robbins - now working for, uucp: {ihnp4|seismo|rutgers}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@seismo.css.GOV Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)