marty@amc-gw.UUCP (Marty Akerman) (10/04/89)
I have a C64 that I recently purchased second-hand. While it seemed fine
at first, it quickly developed a couple of problems that I don't understand.
I'm hoping you more experienced people could help me out.
The unit apparently had been shelved for several years before I bought it.
The problems:
1: It seems to have trouble running canned (purchased) programs from
disk. Sometimes the program will never start up correctly, sometimes
it will spontaneously crap out, even when the program is in an idle
state. Looks like a disk drive problem to me. I bought a cleaning
disk (Allsop) and tried that, but no change. Programs I have written
and stored to disk load and run fine, but they are all (so far) in
basic, and much smaller than the canned programs.
2: Picture quality is generally lousy. The antenna cable (C64 to TV)
is VERY sensitive to orientation, coiling, what it's near, me touching
it, cats, weather, what I had for lunch, etc. Generally what I see is
sinusoidal waves across the picture, sometimes the screen is covered
with snow. It can get so bad that I can't even read those big basic
characters.
What I've done:
1: I've read here recently about power supply problems. Mine measures
4.97 with 0.001 ripple. This does seem to be an older unit, with
no ground at the wall outlet.
2: I've connected my unit to someone else's TV. Picture is MUCH better
there. I can't remember now if I was using my power supply or his,
but I'm led to believe that my unit is fine and the problem is in
the connection or my TV. My TV set has a locked digital tuner, so
I can't "tweak the tuning"
Unrelated questions:
1: I've read and heard about the "fast load cartridge". I gather this
is a cartridge that plugs into the cartridge port on the back and
speeds up disk accesses enormously. Sounds like a terrific idea.
Where can I get one? How does it work?
2: I would be interested in doing some assembly language programming.
Are there assemblers available or do I have to hand assemble (yuk)?
Where can I get one?
3: Any other words of wisdom you could offer a novice C64 hack?labc-2aa@web-4h.berkeley.edu (Greg Burrell) (10/05/89)
In article <936@amc-gw.UUCP> marty@amc-gw.UUCP (Marty Akerman) writes: >I have a C64 that I recently purchased second-hand. >The problems: > 1: It seems to have trouble running canned (purchased) programs from > disk. ... Programs I have written and stored to disk load and run > fine, but they are all (so far) in basic, and much smaller than the > canned programs. Ah, the infamous head-alignment problem. Simply put: the read/write head of your disk drive is out of alignment. The canned programs were written by a drive that has correct head alignment and since your alignment is bad, your drive cannot position itself in the proper place to correctly read all the data. Why does this happen? Largly because copy-protection schemes cause the head to bang repeatedly against the head stop. (That chattering noise you often hear when loading commercial programs.) Eventually the head goes out of alignment like yours. This is both the fault of software publishers who use copy protection and bad design by Commodore. Programs you write and save now will be written to the disk with incorrect alignment. Unfortunately, if you get the alignment fixed you will most likely not be able to read programs you saved under the bad alignment. How do you get the alignment fixed? Several ways: 1. There are programs available that will tell you how far out of alignment your read/write head is and will include instructions on how to adjust it yourself. Drawbacks: Your drive has to be well enough to load the diagnostic program or you have to be able to borrow a good drive. Also, some disassembly of the drive is required. 2. You can look for a repair center that will do this. This might cost. Personally I think option 1 is better because it is very likely that your alignment will go out again sometime in the future. Also, you become more familiar with the drive and how it works. > 2: Picture quality is generally lousy. The antenna cable (C64 to TV) > is VERY sensitive to orientation, coiling, what it's near, me touching > it, cats, weather, what I had for lunch, etc. Generally what I see is > sinusoidal waves across the picture, sometimes the screen is covered > with snow. It can get so bad that I can't even read those big basic > characters. Sounds like your cable is not shielded and is picking up stray interference. Try finding a replacement. > Other Questions: > 1: I've read and heard about the "fast load cartridge". I gather this > is a cartridge that plugs into the cartridge port on the back and > speeds up disk accesses enormously. Sounds like a terrific idea. > Where can I get one? How does it work? There are a lot of fast-load cartridges available. A pretty standard one is called Fast Load and is put out by Epyx. They do not speed up all disk accesses, but do cause most programs to load 3-4 times faster. If there is a software store in town you might try there. If you have Wherehouse records, they sell a lot of software and should have one. Otherwise, pick up a C64 magazine like Compute's Gazette or Commodore and mail order a fast loader. Basically, they bypass a lot of the error checking done by the drive, use faster routines to read data from the disk, and improve communication between the drive and computer. > 2: I would be interested in doing some assembly language programming. > Are there assemblers available or do I have to hand assemble (yuk)? > Where can I get one? Abacus software puts out a decent assembler. Commodore also offers one. Look at a software store, or mail-order catalog. There are several available, but I think the one from Abacus is pretty standard. > 3: Any other words of wisdom you could offer a novice C64 hack? Just have fun. There are a lot of books and mags out there that have lots of info. Particularly good is a magazine called Transactor. Its very technically and hacker oriented. Most importantly, post to this group with your questions. There are a lot of knowledgable people out there just waiting to answer. -Greg Greg Burrell labc-2aa@WEB.berkeley.edu University of California, Berkeley
dyson@lilac.cis.ohio-state.edu (mark l dyson) (10/05/89)
In article <1989Oct5.032118.26864@agate.berkeley.edu> labc-2aa@web-4h (Greg Burrell) writes: >In article <936@amc-gw.UUCP> marty@amc-gw.UUCP (Marty Akerman) writes: > >> 2: I would be interested in doing some assembly language programming. >> Are there assemblers available or do I have to hand assemble (yuk)? >> Where can I get one? > Abacus software puts out a decent assembler. Commodore also offers > one. Look at a software store, or mail-order catalog. There are > several available, but I think the one from Abacus is pretty > standard. > -Greg To add my 2 Pfennig worth, I'm very fond of the 'Power Assembler' in the 'Better Working' stable. It's usually available for around $20.00, and the 'buddy system' is a very powerful assembler. Documentation is fair, and the included libraries are very comprehensive. Your best bet for more info is 'C-64/128 Assembly Language Programming' in the SAMS series. I've not seen a better treatment of the subject. -Mark- ======================================================================================= Anybody can write sharp-looking code on a Mac. Success on a C-128 is a labour of love. =======================================================================================
profesor@wpi.wpi.edu (Matthew E Cross) (10/10/89)
In article <936@amc-gw.UUCP>, marty@amc-gw.UUCP (Marty Akerman) says: >I have a C64 that I recently purchased second-hand. While it seemed fine >at first, it quickly developed a couple of problems that I don't understand. >I'm hoping you more experienced people could help me out. > >The unit apparently had been shelved for several years before I bought it. > >The problems: > > 1: It seems to have trouble running canned (purchased) programs from > disk. Sometimes the program will never start up correctly, sometimes > it will spontaneously crap out, even when the program is in an idle > state. Looks like a disk drive problem to me. I bought a cleaning > disk (Allsop) and tried that, but no change. Programs I have written > and stored to disk load and run fine, but they are all (so far) in > basic, and much smaller than the canned programs. If it is a disk drive problem, it is probably the alignment if it's a 1541. I've owned my system for about 7-8 yrs., and the alignment of the 1541 is a constant problem. It's caused by the way the drive resets the head - by banging it against the track 1 head stop. There is an article in an old RUN magazine that shows you how to fix it, but it's actually not that difficult. You basically just have to disassemble the drive, look for the stepper motor screws, loosen them, adjust motor a little (twist), tighten screws, and try to get a directory. If you get a directory good, try reading the inside and outside tracks (1 and 35). If it reads those quickly and easily, then it is in good alignment. If you can get a hold of Vorpal utilities by Epyx, it has a drive alignment checker on it that helps a lot! Hope this helps...