sentinel@killer.UUCP (The Sentinel) (05/05/87)
-
Hello. I recently picked up a Dallas Semiconductor SmartWatch, and
installed it in my Commodore 128. This is a "no-slot clock" which plugs
into the board underneath a ROM, and is transparent until you need it.
However, I have a problem. It won't do anything. No matter what I do
I can't access it. All I have to go on is the manufacturer's data sheet,
so I think I must me missing something which would be obvious to someone
else.
So, has anyone had any experience with this chip in a 6502-based computer?
Any help, suggestions, or sample code would be greatly appreciated. Is there
anything unusual about the bus structure of the C-128 (or 6502) which would
cause ROM access to be carried out differently from, say, an 8088-based PC
clone?
Many thanks in advance,
--TS
--
Rob Tillotson ...ihnp4!killer!sentinel
3922-1 Newport Ave. -or-
Fort Wayne, IN 46805 ...rutgers!unirot!sentinel
(219) 483-2722 (top one preferred)grr@cbmvax.cbm.UUCP (George Robbins) (05/10/87)
In article <849@killer.UUCP> sentinel@killer.UUCP (The Sentinel) writes: > > Hello. I recently picked up a Dallas Semiconductor SmartWatch, and > installed it in my Commodore 128. This is a "no-slot clock" which plugs > into the board underneath a ROM, and is transparent until you need it. > > However, I have a problem. It won't do anything. No matter what I do > I can't access it. My understanding is that these devices require some ritual address sequence to become activated. You may need to write a machine language subroutine to access the clock, since accessing from basic would involve other possible ROM accesses. Also check that the pin-out expected by the clock device is compatible with the C128 ROM socket... -- 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)
colin@vu-vlsi.UUCP (Colin Kelley) (05/11/87)
In article <849@killer.UUCP> sentinel@killer.UUCP (The Sentinel) writes: > > I recently picked up a Dallas Semiconductor SmartWatch...[called SW below] > This is a "no-slot clock" which plugs >into the board underneath a ROM, and is transparent until you need it. I've been toying with the same thing--I've been trying to install the SmartWatch in my PClone. The problem is: the SW is intended for a RAM, not a ROM. Fortunately the pin-outs are virtually identical. However, the SW documentation says that it looks for the 64-bit pattern on D0 while CE* (Chip Enable) and WE* (Write Enable) are both asserted (low). I had to bend the WE* pin on the SW and connect it directly to the microprocessor WR*, since that pin was PGM* on the ROM and had been tied high. (You ordinarily can't write to those ROMs you know :-) On both the ROMs in my system, the designers chose to tie CE* permanently low and just deal with OE*, which I believe is the only remaining barrier to getting my SW to work. If I can get the CE* to be decoded also (maybe just tie CE* and OE* together, although the timing might be a little tight) I think it'll work... I assume the reason you're trying this that you (like me) have seen the adds for the "Slotless Clock" in computer magazines, and it's clearly a Dallas Semiconductor product. I assume that they've modified it slighty to work with ROMs. My guess is that they use A0 instead of D0, and OE* instead of CE*, so that the software only has to READ from 64 magic locations in sequence rather than write 64 magic values in sequence. Anyone know for sure? If all else fails, I'm considering wire-wrapping a little static RAM board just so I can get at the clock. I'm sure I can find something to put in 2K (or 8K) of non-volatile RAM! -Colin Kelley ..{cbmvax,pyrnj,bpa}!vu-vlsi!colin
gardner@kodak.UUCP (dick gardner) (05/11/87)
In article <849@killer.UUCP> sentinel@killer.UUCP (The Sentinel) writes: >- > Hello. I recently picked up a Dallas Semiconductor SmartWatch, and >installed it in my Commodore 128. This is a "no-slot clock" which plugs >into the board underneath a ROM, and is transparent until you need it. > > However, I have a problem. It won't do anything. No matter what I do >I can't access it. All I have to go on is the manufacturer's data sheet, >so I think I must me missing something which would be obvious to someone >else. > > So, has anyone had any experience with this chip in a 6502-based computer? >Any help, suggestions, or sample code would be greatly appreciated. Is there >anything unusual about the bus structure of the C-128 (or 6502) which would >cause ROM access to be carried out differently from, say, an 8088-based PC >clone? > In order to use the Smartwatch, you must devote 1 byte of the ram contained in the socket for use by the clock device. You prepare to read/write to the clock by first reading the device to start the sequence, and then writing the 64 bit code sequence of bits to the dummy clock location in ram. You are then able to read or write the clock values, but you must empty/fill the entire 64 bit pattern. You CANNOT selectively read/write any single location. I could mail you some 8051 code that works if you wish, or I can supply you with the issue and date of an article that Steve Ciarcia wrote for BYTE magazine (written in Basic, I think). This is a really neat device that works quite well. I am sure that there is nothing special about the 6502 that prevents you from using it. Just remember that it is only the least significant bit that transfers information, and of course you must handle it a byte at a time, and shift, and all that stuff. I suspect that your trouble is in not doing the first read before beginning the key sequence. I know that was my problem when I first used this device. I placed several calls to Dallas Semi before getting it going. Good luck. Hope this info helps. =#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=# Dick Gardner -- Eastman Kodak Co. Rochester, New York 14650 Phone: (716) 477-1002 UUCP: {allegra,seismo}!rochester!kodak!gardner "Research is what I do when I don't know what I'm doing" =#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#=#
rex@otto.COM (Rex Jolliff) (05/15/87)
Summary: Expires: Sender: Followup-To: Distribution: In article <849@killer.UUCP> sentinel@killer.UUCP (The Sentinel) writes: >- >... Is there >anything unusual about the bus structure of the C-128 (or 6502) which would >cause ROM access to be carried out differently ... Yes. The commodore's bus does not allow you to write to a ROM. If a write is attempted, the appropriate RAM bank is automatically selected. Sounds like your going to have a hard time making that thing work. >-- >Rob Tillotson ...ihnp4!killer!sentinel Hope I helped out... ** Rex! ** [ this line was inserted in an attempt to fool the vicious line counter... ] -- ------------------------------------------------------------------------------- Rex Jolliff (rex@otto.UUCP) |Disclaimer: The Sun Newspaper - | The opinions and comments in this Nevada's Largest Daily Morning Newspaper |article are my own and in no way |reflect the opinions of my employers. -------------------------------------------------------------------------------