My recent eBay acquisitions: Apple //c and C64

[mkarcz]

Hello everyone!

Nostalgia hit me hard again recently and I yielded to the urge to purchase two vintage systems. I bought Apple //c setup with working computer, color monitor and external 5.25 drive plus Image Writer printer with extra paper and replacement ink cassette and tons of software. I also got C64 with 1541 drive with JiffyDos installed. Fun, fun, fun!
I already owned 2 C64 C-s that I brought from Poland, but I wanted to have one US/NTSC version in this funny looking classic case. It was made in 1983!
I already ordered serial null cable for Apple to transfer images between it and PC. Oh boy oh boy oh boy!

Please see the pictures here:
http://www.flickr.com/photos/68573003@N ... 968007691/

PS: I have never owned Apple computer in the 80s or 90s (or ever in fact, being Commodore and later a PC/Windows/Linux user). So this apple //c is my first and I already love this system. Both have 6502 inside (with apple having 65C02). C64 seems to be much better gaming machine with comparable or better than apple graphics and sound capabilities, while apple //c is more business/work oriented, with its 80 column text mode built in, booting DOS from diskette, 1-bit PC like speaker, hardware serial ports etc. Cute little machine. I fell in love with it just for its looks, but now learning how to use it I like it even more.

Does anybody on this forum own apple //c owner's manual? (and perhaps willing to part with it or share a scanned copy?). These seem to be quite rare, found just one on e-bay, auction is now around $9 plus $5 shipping and I am sure it will go up in the next 2 days that remain for this auction.

Cheers!

[GARTHWILSON]

I have a lot of C64, C128, and Apple II computers, accessories, and discs too that I would like to find a good home for. I'm in Southern California, Los Angeles County. I don't need any money for it, but I don't want to donate it to the land fill! I'll look and see if I have an Apple IIc manual. I don't know what to expect since none of my Apple II's are IIc's, but there are boxes of Apple books and manuals. I expect it would be an awful lot to scan, so I might end up mailing it. I don't know how soon I'll be able to get to it. This weekend is rather booked up.

[GARTHWILSON]

I just went through three boxes of Apple II books & manuals (that does not include the Commodore books & manuals), and there was no IIc manual.

There's a Yahoo Apple II forum at http://tech.groups.yahoo.com/group/AppleII/ . You might see what you can find there. There's not much activity on it, but if someone brings up something interesting, it should produce a flurry of activity.

[mkarcz]

Thanks a lot for looking, Garth! I really appreciate it!

Well, if you find some time in the future and it would not be too much trouble, please send me a list of apple II related materials that you have. Perhaps I can pick something useful and we would agree to the price/shipment. Once again, thank you very much for looking.

I have another kind request to forum members regarding my recent acquisition, specifically regarding C64. This weekend I have been playing with this hardware (C64 with JiffyDos) and noticed that it is not working well with all software titles that work fine on my other C64, especially with programs using hi-res graphics, using possibly some cycle-stealing tricks, like most of the graphic intensive games on C64 do. It is actually very high rate of incompatibility (close to 50%). When I opened this particular C64 for the 1st time I noticed there were 2 ICs replaced with mods, one Kernal ROM (which is I guess a JiffyDos) but also, the PLA chip is replaced with EPROM mod (this is 1983 mobo, the PLA chip symbol is U17, that one is replaced with 64 x 8 EPROM)). I believe this mod is causing problem. U17 PLA is a custom 64 IC and I think that the chip that replaced it, whatever user was trying to achieve, either repair or some home-made modification, has a bug causing this C64 not to be fully, well C64 compatible.

I do not believe that replacing PLA in C64 is part of JiffyDos modification, but please correct me if I am wrong?

My request is - if anybody has C64 PLA chip (U17) and willing to part with it, I am interested.

Thanks!

[ElEctric_EyE]

Hi Marek,
Nice to hear of your acquisitions. If noone here can help you, I know for sure the many C-64 experts over at www.lemon64.com can help you. I think even the creator of jiffyDOS hangs out there... Anyway, I've heard that you can buy a PLA to put into the socket. Maybe I read it at zimmerman's website? Not sure about compatibility issues though, lemon64 can help there too. Good luck! Let us know what you find out.

[BigDumbDinosaur]

mkarcz wrote:

I do not believe that replacing PLA in C64 is part of JiffyDos modification, but please correct me if I am wrong?

It isn't. Most likely the PLA was replaced due to failure. An EPROM can be used as a "poor man's PLA" in situations like that. As the PLA is central to the C-64's operation, its failure was fatal to the system.

[Nightmaretony]

Thanks on the donate hint, Garth. I will on most of my ][ based stuff.

[ChuckT]

I would try searching library catalogs online for a manual. Some of the older and bigger libraries probably have one.

We used Apple IIe's at school and I've never seen a manual. There are issues of Compute's Gazette! online and you can also buy a CD from Ebay on the different computer magazines as they have them all in .pdf format.

Commodore manuals:

http://www.commodore.ca/manuals/default.htm

Magazine issues:

http://www.commodore.ca/gallery/magazin ... e-1-43.htm

I believe Compute's Gazette had programs for different platforms other than Commodore. You can learn a lot from reading different programs.

http://www.applefritter.com/forum/84

[BigEd]

PDFs of the apple //c reference manuals, and some other docs, can be found at the bottom of this page
http://www.1000bit.it/scheda.asp?id=2
And also here
http://www.old-computers.com/museum/docs.asp?c=69&st=1
But I don't see an owner's manual or user guide as such.

[mkarcz]

Thank you guys for all the replies. Very helpful.
I did find the 27C512 EPROM to PLA adapter schematics. I checked connections in the adapter found in my C64. All were OK. I replaced old IC socket with the new, better quality one with round pins. I re-did the adapter in fact. I soldered the EPROM IC to the adapter's IC socket to make sure there is no glitch due to weak contact. Unfortunately C64 acts the same way, some games will have trash/artifacts on the screen, some will not run, some are fine. My guess is, this particular C64 model does not like the timing of EPROM used in this repair or the chip is defective. I found just one auction of C64's PLA on eBay, it is buy it now for $29.99, kind of steep, but I think I will go for it. After all, I want this C64 to work (always wanted to have one NTSC version and in the breadbin case). AFAIK this particular EPROM made by ST (recommended by C64 experts for PLA repair due to its adequate timing/electrical characteristics) is not produced anymore as well, so I can not even get a new one to re-program and see if it'd be a better "poor man's PLA" for my C64.

Cheers.

[ElEctric_EyE]

Earlier I was referring to something I've found in the past based on my faulty memory. I looked ->it<- up just now. The replacement for a faulty original PLA is not based on an EEPROM. I think the ABEL formula's were more geared towards a CPLD. Surely it would fit in a Xilinx 44-pin QFP 9536. You'll just need an adapter for the 44-pin QFP CPLD to 28-pin .6" DIP. Epboard.com on the web used to be pretty good with these type adapters.

[mkarcz]

Well, my PLA repair is based on EPROM, the chip is marked ST 27C512 and it matches the description about typical PLA repairs done with these chips, that I found on the internet.
Anyway, I am a little disappointed, because my PLA arrived in mail today, I replaced it and C64 still acts up the same way as before.
I am stumped. Next on the list of suspects is VIC.
It is also possible that NTSC version can not run some software that was timed for PAL systems (my hardware and software comes mostly from Europe), but I doubt it.
Looking now for VIC chip for C64

As for the apple //c system, the Image Writer printer came in damaged (no power). They eBay store guy was so nice, offered me refund immediately. But I decided that I would risk repairing it myself and I succeeded! It is awesome. It is actually my first 8-bit system with a printer. I believe with some not overly complicated interface I could also make this printer work with my C64 unit. It is a serial printer, just as C64 printers were.

Cheers!

[mkarcz]

Update:
I am reading the article about differences between PAL and NTSC video systems in context of C64 software and hardware compatibility and it looks like I should probably save $$ and not to buy a new VIC chip. Appears to be a normal thing for some software titles to have problems, when designed and timed for video raster rate of PAL system when running on NTSC system. If all lines are used in PAL designed software, routine will not complete on NTSC system resulting in distorted screen or failure.