• Please review our updated Terms and Rules here

Apple ii europlus

David_M said:
The MOS 6502A should work fine.
Given that the CPU was fried, suspect the data bus buffers. The address bus buffers should be fine because they only have inputs connected to the CPU.

Three chirps with a standard ROM or the test ROM I posted?
Click to expand...

With the standard rom (not yet got a programmer), but it only did it once.

Don't want to go further with the BBC chip as that's returned to its machine, so step one is bew CPU before more investigation.
 
Gary C said:
Cool. Makes the schlumberge 635 I used at work look a bit over the top.
Click to expand...

I can be a bit disorganised and always find heaps of chips when I clean up my workbench, I currently have about half a Kg of TTL and memory chips of unknown status. Periodically I sort them and use the tester on them before putting them back in the parts drawers.
Mine is due to be replaced soon, the test button has gotten a bit flakey due to over use.
 
David_M said:
I can be a bit disorganised and always find heaps of chips when I clean up my workbench, I currently have about half a Kg of TTL and memory chips of unknown status. Periodically I sort them and use the tester on them before putting them back in the parts drawers.
Mine is due to be replaced soon, the test button has gotten a bit flakey due to over use.
Click to expand...

Well ,its been a while since last post, but the Apple is now working !

Got the LS tester and tracked down a faulty chip eventually, but hampered by a recurring PSU fault. It would start and run fine then fail to start without warning. Stripping it our would always fix it, but the last time it also failed to run when on the bench, but sprang to life with a small prod.

Had a good look round and soldered up the collector on the big transistor and that seemed to have fixed it (it did suffer quite a dramatic failure and needed all power caps, plus the rectifier replacing to fix initially)

So next is the keyboard. Now stripped and the faulty stalk removed, just waiting for a replacement. Three of the little 'buttons' aligning the contact strips did come off when the strip was lifted (not the bigger ones, but the little ones at the end of a strip), but a melted blob from a cable tie, shaped to match has fixed that.

Just on the lookout for a Disk II to complete, though an emulator would probably be better.

Anyway, this is fun. Almost time to switch to the TRS-80 and see if it still works.

Eeek, just noticed it was July when I last updated, where does the time go. I need to retire.
 
Damn, New part wasnt the right bit (for a later keyboard)

Does anyone know of a source of the stalks for the mechanical keyboard (RFI Type A I believe) ?

I have bodged the broken stalk, but it means the key isnt quite sitting right and would be much better with the right bit.

about 80% of the keys were not working, but a bit of careful cleaning of the gold contacts and all operational.


Wonder if the Z80 softcard works....
 
Last edited:
Gary C said:
Damn, New part wasnt the right bit (for a later keyboard)

Does anyone know of a source of the stalks for the mechanical keyboard (RFI Type A I believe) ?

.
Click to expand...

Found some. Shipping is a bit steep from the US, anyone else need any ?
 
The clock is never a neat square wave, so that is not unusual.
What side of the buffer are you getting the low levels on the address bus? If it is the CPU side then it may be a CPU problem.
 
On a side note I have picked up.a second ii+ MB that needs a fix. Chip swap time but must improve my SD protection on my bench. Might borrow an old lot from my Homeywell DPS 6 days at work :)

At least it has the correct MOS 6502 so that's now in the working board.
 
Yey, now almost working

Keyboard was poor. Z didnt work at all, and the +- key had snapped off. New post and key plus a really good clean of the contacts has restored the keyboard and it works really positive now. One slightly strange fault exists, the reset doesnt work. Its the two piece keyboard and from the diagram, it just pulls pin 6 down to 0v either via the ctrl key or the reset on its own, but no matter where I put the switch, it refuses to reset.

Disk II interface installed and drive spins, but I dont have a bootable DOS disk so its either find one or use ADTpro but not tried the cassette port yet.

Anyone have a DOS 3.3 5.25 floppy :)
 
Sure but you're better off just bootstrapping ADT in my opinion. Especially now that you don't have to key it in anymore.
 
ADTpro is brilliant !

Revealed a problem though, the cassette output connector is dodgy and needs the plug holding up to get it to work. Might be a cracked joint or a relaxed spring.

Good news, Z80 softcard works !, wrote a boot CPM disk with ADT and booted to the A> prompt. After the PSU failure and the blown 6502 I did think it might be damaged.

Disk drive needs a bit of work, floppy isnt centering properly every time when the door is closed and I cant yet see why and the second drive just steps to the stop then throws an I/O error.

Also got a video to VGA converter which works ok and is great for testing without having to mess about with big tubed screens, but could be better. Anyone got a recommendation of a good one ?
 
Arrg

Machine locked up then refused to reboot, stuck at a screen with white stripes. Removed the Softcard and it boots fine.

Quick diag of the softcard and one of the Tri-state hex buffers is showing bad, which makes sense as I suppose its locking the bus during boot. New one on order from Farnell (actually, a set just in case) who have some old stock left by the looks of it, fingers crossed.
 
KC9UDX said:
Do you mean the ⅛" jack on the motherboard?
Click to expand...

Yes, the vertical female socket mounted on the motherboard that the cassette lead plugs into. Mine is a bit dicky and without a serial card, im using it for ADTpro.

Want one thats cosmetically similar, and the only one ive found has a transparent side.
 
You must log in or register to reply here.
Back
Top