Apple II (Not Plus) Board has Issues

[DistantStar001]

Recently got a Rev.2 Apple II board. Originally had AppleSoft ROMs, But the AutoStart had a bad pin (broke off) so I replaced them with an Integer set I had on a II+ board. The board boots to the Machine Monitor, and with a ROM switch card (AppleSoft onboard) in Slot 0, it will go to BASIC. I connected a Disk II in Slot 6, and put in a copy of Apple-cillin II. It loaded fine, so I tried a copy of DOS 3.3, and it either hangs after splash screen or crashes. I figured that it was a RAM issue, and indeed several of the chips had corroded legs, but even with good replacements, the issue continued. I tried rotating chips, DeoxIT in all the sockets... I even replaced the CPU, drives and Disk II Cards. No luck. 

So I tried loading from "cassette" (Apple II Game Server). And it also crashed out mid load (with or without any card installed). 

Eventually, I tried changing my configuration. First, I tried changing the disk controller slot. But that has no effect. So then I moved the ROM Switch Card to slot 3 and suddenly, IT WORKS!!! To be sure, I removed the ROM card, booted up, dropped into BASIC, PR#6 and it loaded DOS too. So I seem to have an issue with Slot 0. 

I installed a Z-80 Soft card clone into the suspect slot (tested on a II+), but get a "SOFT CARD NOT FOUND" error. Moved it to slots 1, 2, and 4, but only got garbage screens. 

So far, I haven't managed to load any games. BattleZone, Centipede, so forth... All disks tested on my //e, but nothing's loading on the II. I do have a little sine wave program in BASIC that makes use of high-res graphics on my DOS disks and that loads and runs fine.


To recap: Computer boots with ROM card in Sot 0 (in both the on and off positions), but won't load DOS. DOS loads with no ROM Card, or card in slot 3. Games won't load from disk, and "cassettes" crash mid load. Disk II Cards work in Slots 5, 6, and 7. Z-80 Cards (tried two, both tested in another machine) aren't recognized in Slot 0, and fail to boot in any other. Both upper and lower RAM passes Apple-Cillin tests. 

Any Ideas? Also, on the off chance I need to replace Slot 0, any idea where I can get a matching edge-connector? It's kind of a dark green that I've ever seen before. So no idea where to get it.

 

[DistantStar001]

Okay.  There was a RAM issue!  I basically had to strip it down to its base 16k and then work my way up to a full set of working chips bank by bank, but it now loads programs from disk and cassette!  However, there's still an issue with Slot 0.  I tried installing a Language Card and it's not being recognized, either by DOS or diagnostic software, and load failures continue when the ROM Card is in that slot.

 

Side note: When I said that the ROM card was in Slot 3, I meant 2 as the switch is obstructed by the case in 3.

[MarkO]

On 10/29/2023 at 10:05 PM, DistantStar001 said:

Okay.  There was a RAM issue!  I basically had to strip it down to its base 16k and then work my way up to a full set of working chips bank by bank, but it now loads programs from disk and cassette!  However, there's still an issue with Slot 0.  I tried installing a Language Card and it's not being recognized, either by DOS or diagnostic software, and load failures continue when the ROM Card is in that slot.

 

Side note: When I said that the ROM card was in Slot 3, I meant 2 as the switch is obstructed by the case in 3.

Are you using Apple's Language Card, or a 3rd Party, like Applied Engineering's??  
The Apple Language Card requires removing a RAM Chip from the MB and placing on the Language Card and Running the Jumper Ribbon down to the MB...

 

If you have the Apple ROM Card in Slot 0, all works OK??

 

MarkO

[DistantStar001]

2 hours ago, MarkO said:

Are you using Apple's Language Card, or a 3rd Party, like Applied Engineering's??  
The Apple Language Card requires removing a RAM Chip from the MB and placing on the Language Card and Running the Jumper Ribbon down to the MB...

No.  It's a third party card.  But I am aware of the ribbon cable to the RAM socket at E3.  I have two of these cards.  The other is in a II+, so I had a model to get it right.  Also, the card was tested in my other II+.  

 

2 hours ago, MarkO said:

If you have the Apple ROM Card in Slot 0, all works OK??

No.  The computer seems to boot ok, but loading programs from either disk or cassette always crashes.  However, if I put the ROM Card in Slot 2, everything works fine.  I've tried reflowing the solder joints on Slot 0 with no luck.  

 

At present, the computer seems to be working perfectly (minus Slot 0).  Beeps on boot.  On boot to Integer BASIC, I get a solid screen of ???????????, with an * and cursor at the bottom.  On AppleSoft, get the usual APPLE ][ screen and the floppy starts spinning.  

[trash_44fr]

Hi,

You can try to replace the 74LS138 at position H2 and see if the ROM Card in slot 0 is working.

You have probably another issue as the Z80 card doesn't work at all.