Hi All,
Some time back I inherited a complete Apple II+ system with language card, parallel card, Hayes modem, Serial Post, Z80 card, and Disk II controller along with the monitor, disk drives, printer and software.
I finally got around to replacing all of the capacitors in the power supply (thanks Console5), and cleaning the system up.
When powered on, it tries to boot from disk. I can successfully boot into CP/M, as well as some games, etc.
But when at the "APPLE ][" banner with the drive spinning, if I press CTRL+RESET, I'm dropped to the Monitor (*) prompt.
3DOG, CTRL+B Enter, all of that doesn't get me to either the AppleSoft prompt or Integer Basic prompts. It's like boot from disk, or monitor only.
Took all the cards out, reseated chips, everything, same behavior. I mean, the machine works, I just can't seem to get to BASIC.
Thoughts? It's really nice machine :)
Chris
So with all cards removed, you get "APPLE ][" and the * monitor prompt when switching on power?
Try typing E000G (that's the letter E, three zeros, G)
This is how you cold-start BASIC.
There may be errors in the E0 or E8 ROMs preventing them from starting
I can't recall off the top of my head if when the cards were removed it said "Apple ][" at the top, but I know when the thing is started in that configuration, it drops me to the monitor prompt.
What type of chips are the ROMs? Is it something I can read in my EEPROM programmer and do a checksum verification to make sure they're still good?
I find it amusing it runs games and CP/M (though I know that's on a separate processor) without issue, but won't boot to BASIC.
I find it amusing you replaced all capacitors in the PSU. You can check the ROMs checksum with many diagnosticprograms. Are you sure each ROM chip is in its designated socket?
Not sure why the capacitor replacement was amusing, I had a case of RIFA madness with the machine (my office still smells like a forest fire) and just decided that after 40+ years, it's probably not a bad idea to just shotgun the thing.
I'll double check that the ROMs are in the correct place. Based on the origins of this machine along with when and where I acquired it, I'm certain it hasn't been screwed with, it was put away years ago.
I ordered a Floppy Emu, so hopefully I'll get a shipment notice on that soon and can run some of these diagnostics a bit easier.
Monitor boots into:
0D04- A=FE X=DC Y=D3 P=B5 S=F2
E000G has no affect, just a beep and the same line above.
Chris
Most of the non-RIFA caps in Apple power supplies don't usually fail. If I get a power supply that is working I pre-emptively replace the RIFA caps but I don't touch any of the electrolytics unless they show signs of leakage, bulging, etc. I've bought several power supplies from people who had done a complete re-cap trying to fix the power supply and it didn't work. I'm not an expert on that kind of electronics but from what I've heard it is usually one of the other parts that fails, often a diode or the opto-coupler.
I actually usually "shotgun" any failed supply a different way. I did a few with ReActive Micro's replacement board which works great and is super easy. The last several I have done I have used a Mean Well PT-65B power supply and an extra LM7905 regulator for the -5V mounted on a piece of plexi cut and drilled to fit where the original supply board went. That works great and is 1/2 the price of the RM board.
I think the replacement board is better than a re-cap because you're getting a completely new power supply and one with higher output as well plus it is actually a lot less work and pretty much guaranteed to work, where as like I said, sometimes a re-cap doesn't fix the problem.
If you are ever inerested in doing the conversion there are threads here on Applefritter with pictures and everything of how it is done.
As for what is wrong with your ][+, it sure sounds like the contents of your Applesoft ROMs are corrupted. If you can boot up the Apple Dealer Diagnostics or XPS Diagnostics or one of the others like MECC, they usually have a ROM test. That would tell you for sure. You can find those for download on Asimov or elsewhere. If you need help getting them onto a floppy or something I am sure someone around here can help.
Curious if those are included on the BMOW "Vintage Software" SD card that's included with the Floppy Emu deluxe package I ordered yesterday (still haven't heard a status on the order).
I think I'll just sit in a holding pattern until that device arrives as it'll make getting the required software to the machine a heck of a lot easier. I appreciate everyone's input on what the problem could be.
Can replacement ROMs be burned into UV EPROMS and installed if need be? What type of chip are the ROMs?
Chris
Those are not on the BMOW SD card, but you can download them from Asimov very easily and copy them onto the card. Here is a link to them for your convenience:
https://mirrors.apple2.org.za/ftp.apple.asimov.net/images/disk_utils/diagnostics/
Replacement ROMs can be burned onto 2716 type EPROMs, but there are caveats -- you need an adapter socket because Apple used mask programmed 9316 ROMs with the device select lines inverted from what EPROMs normally have. One place you can get those is ReActive Micro:
https://www.reactivemicro.com/product-category/adapters/
They have a couple different types of adapters on there. However, that said, you might also consider the ROMX product, as it has a bunch of extra features. It is also on that link above.
I've used the ROMX product and it is good. One of the people who make it is active here on Applefritter.
Thanks kindly. I'm doing my best to try and keep the system as original as possible, that may be considerably more expensive in the long run, but I see retrocomputing having some longevity to it, so I think it's worth it.
It would appear that I'm at a stopping point on this until the Floppy Emu arrives, so when that happens I'll do some more digging with diagnostics and see what I come up with.
Unless there are further suggestions, of course.
Chris
ROMX requires no permanent modifications to the system. There's basically no way to completely keep it original unless you can find original ROMs and those would have to come out of a donor machine because replacements haven't been available for, well, decades. As for a ][+ being valuable in our lifetime? Probably not. Apple made a lot of them, and they aren't rare or hard to find. Original Apple ][, in particular the very early ones are the only ones that are somewhat rare and collectible. Don't take this as being critical of the ][+. It's a great and fun machine -- to use. It's just not really ever going to be worth massive amounts to any great extent. That means feel free to do what you need to do to make it work and be fun. Products like the BMOW FloppyEmu aren't "vintage" either, but they sure do make working with an Apple II a pleasure. We would have killed for something like that back in the day.
Oh I completely understand. I'm not looking at them as a financial investment, moreso a "caretaker" who can restore the machine and potentially pass it on as a refurbished working unit to someone younger who, at some point may actually be able to make money on it. Who knows. In the here and now it's for my love of restoring electronics and my personal amusement.
Granted Apple made a ton of them, but how many have been recycled, how many are in a non-working state, and how many have been refurbished and maintained?
I'll look into the ROMx unit once I have some answers from diagnostic utilities as to if thats the problem. I assume that just plugs in one ROM socket and that's it.
I will say it's pretty nifty running CP/M on it. Been a heck of a long time since I've used that OS.
Unfortunately the ProDOS and DOS 3.3 disks I have don't boot the system, I just get some awful noise from the disk drive which I would chalk up to failed media, since I'm able to boot games and CP/M.
Chris
If you can boot machine language disks but can't get to AppleSoft then there is a corruption (or a bad connection, bad socket or broken trace) in your ROM set.
Clearly the F8 ROM is alright - but one or more of the other 5 has issues.
The ROM/X solution is a valid one to get your machine working int he near term while you sort out what ROMS are bad, but I second the motion to run a diagnostic software like Apple-Cillin or APTEST to run some ROM checks - it may shed some light on which particular ROM is failed.
Baldrick brings up a very good point. The sockets the Apple used back in the day were often very dodgy. It is possible that one has corrosion or has just plain failed. If it hasn't already been done, I'd carefully remove the ROM chips and chean them and thoroughly inspect the sockets with magnification. If any look suspect the connections on each pin can be verified with a meter.
Thanks guys. I spent some time on the machine with DeOxIt going through every IC with no success, but I'm thinking reflowing solder on the ROM sockets is probably the next best bet.
Once my Floppy Emu ships and arrives, I will have much better insight into this problem I'm sure. I'll keep everyone posted, and keep the suggestions coming!
Chris
UPDATE: Found a bad socket on D0 and was able to get a single-beep "APPLE ][" banner but no prompt. Not too concerned about that at the moment, but man can I see how cheap these sockets are, just like you said. I'll bring a handful of them with me next week and replace what needs replacing. Where there's one, there's usually more.
you could always try the II+ ROM replacement board.
I like that - thanks! That may be the way I go.
Well this is pointing more and more towards a bad ROM or LS138 (and I question the LS138 as being the problem, I swapped them around with no change in situation.). I spent the morning replacing the D0 socket and it made no difference. Right to the monitor prompt. Ran continuity of all ROM chips through the respective interstitials (8304, 74LS138, 8197, etc.) and unless one of those ICs is bad (entirely possible!), it does not appear to be a board-level problem.
I checked continutity of all chip select, address, and data lines on the ROMs and again, back through their interstitials. I'd guess that the 8304 is probably OK, and the 8T97s are probably OK, but that it's either a bad ROM or a bad 74LS138. Anyone care to chime in?
Man I need that floppy emu!!!!
That's not really that different than what ROMX for ][+ does, except that it doesn't provide as much functionality. It is fairly cheap though, and it would probably work unless there are other problems with that board.
I found this old post in the forum that might be of some use for you. It mentions many of the same chips that you are questioning.
https://www.applefritter.com/content/fixed-apple-ii-plus-bad-memoryrom-saga-continues
Good luck!
Joe
Joe - thanks, I'll check it out. Looks like my Floppy Emu is shipping today, so I hope to get some bona-fide answers this week. Picked up a IIe yesterday that seems to be working (and it has a Z80 softcard in it as well!), self-test shows "RAM:" though. That's the next project. And I'm not taking any more on until these are done :)
Chris
So, like the IIe, I can now boot off of the Floppy Emu and run diagnostics.
ROM D0 fails testing. I think that's a full stop right there. All others seem to pass.
Would be nice to find an original D0 ROM, but at least I know which direction to go now!
Thanks all,
Chris
Brief follow-up for everyone. I replaced the D0 ROM with a factory replacement obtained on eBay, and the machine is working great now, and is still in "all original" condition. Boots to BASIC as it should, and passes all tests in multiple diagnostic software packages.
Thanks for all the help!
Chris
Glad to hear it is working. I imagine that ROM probably came from a machine being parted out. Hope it was because of some major problem not just someone chopping a machine to squeeze a few more dollars out of it because everything like that is usually worth more in parts than as a whole.
You and me both. The gent had many, many IIe parts listed, so who knows what the source was. I don't like the thought of chop-shop machines either, but as long as I'm not participating in it, I'd rather use the outcome to get something back on its feet.
It's been nice to get this II+ back to life, and the IIe I've discussed in another thread back online as well. Now I just need some help getting a Disk II drive working, I have one that's being rather recalcitrant. Keep forgetting to grab some chips from home to work on it with (LS125/ULN3002).