Search found 72 matches

by guus.assmann
Sat Mar 06, 2021 3:02 pm
Forum: FLOPPY DRIVES KITS & UPGRADES
Topic: HD V6 board connections (STe)
Replies: 10
Views: 1125

HD V6 board connections (STe)

My experience, try not to bend the pins. They are quite hard and will break easy. Just make sure the holes in the HD module are as clean as possible. Then insert the thin end of the strip into the socket. And place the HD module on top of the strip. The pins will be in the holes at an angle, but tha...
by guus.assmann
Sun Feb 07, 2021 3:10 pm
Forum: ATARI FOR SALE & WANTED
Topic: WANTED MegaST 68881 copro board C103067 / SPF004
Replies: 11
Views: 1503

WANTED MegaST 68881 copro board C103067 / SPF004

Hello, I do have a complete card, with a 68881. It is an original, with one "flaw". The Oscillator has been removed and put in a socket. This has been done to test the Co-Pro at higher speeds, and it does. I'm willing to sell it for a good price. (definitely not top dollar) Downside is, that I'm in ...
by guus.assmann
Wed Jun 10, 2020 8:53 pm
Forum: 8 BIT CORNER
Topic: 65XE boot issues
Replies: 34
Views: 8130

65XE boot issues

Hello Ziggy, Good to see that. Also good you didn't give up. Now you can also consider to expand the memory to more than 128K. The memory error must be a defect in the address lines. So check the lines between the Freddy chip and the address-lines of the Ram. Also, the address lines from CPU to Fred...
by guus.assmann
Wed Jun 10, 2020 3:42 pm
Forum: 8 BIT CORNER
Topic: 65XE boot issues
Replies: 34
Views: 8130

65XE boot issues

Hello, Good to read that I'm contributing. If it's not solved with the MMU, then we'll keep rethinking. I'm positive that it's possible to get the board 100% again, it's working for a big part anyway. Pitty that UK and NL are so far apart and postage is not so cheap. Anyway, keep up the good work. I...
by guus.assmann
Tue Jun 09, 2020 7:04 pm
Forum: 8 BIT CORNER
Topic: A little bit of 8 Bit: 65XE upgrade to 128k RAM
Replies: 65
Views: 17119

A little bit of 8 Bit: 65XE upgrade to 128k RAM

Good that you found the problem. :D Soldering jobs are not always as easy as they look. This may not be a reset problem but a totally different one. To check that theory, take a game cartridge. Switch off, plug the cartridge and switch on. The cartridge should run. Now switch off, pull the cartridge...
by guus.assmann
Tue Jun 09, 2020 6:54 pm
Forum: 8 BIT CORNER
Topic: 65XE boot issues
Replies: 34
Views: 8130

65XE boot issues

Sure I know I don't have to answer fast. But I do know how frustrating it can be if a computer problem eludes you. The problem on this one seems to do so. My next point of action would be to desolder the MMU. But for me that's not such a big deal, I've done it many times. And I hate to destroy possi...
by guus.assmann
Mon Jun 08, 2020 6:41 pm
Forum: 8 BIT CORNER
Topic: A little bit of 8 Bit: 65XE upgrade to 128k RAM
Replies: 65
Views: 17119

Re: A little bit of 8 Bit: 65XE upgrade to 128k RAM

Hello, Did you leave pin 7, 8, 9, 12 and 13 from the GAL out of the board and bend them up? They shouldn't make any connection to the MB. The redish screen usually means a Ram fault or the CPU not running. To test the standard part, remove R111 at the side that's not connected to pin 15 of the Ram a...
by guus.assmann
Mon Jun 08, 2020 6:17 pm
Forum: 8 BIT CORNER
Topic: 65XE boot issues
Replies: 34
Views: 8130

65XE boot issues

Hello again, Sorry it took a while. I'm not in the habit of checking a Forum very often. The value on pin 8 of MMU seems a bit low. This is a line from the cartridge connector to the MMU and has a 1K resistor to GND. And nothing more. It's the line RD5 and a cartridge may use that to disable Ram (an...
by guus.assmann
Sun Jun 07, 2020 12:50 pm
Forum: 8 BIT CORNER
Topic: 65XE boot issues
Replies: 34
Views: 8130

65XE boot issues

Yes, you're right its only 20 pins for the MMU. OK, some more TTL logic. All voltages between 0 and 0,8V are logical zero. And depending on the exact logic family, anything abouve 3,5V is logic one. (Mostly, >4,8V is more common) In between is "not determined". (Can also be an active signal or a flo...
by guus.assmann
Sat Jun 06, 2020 6:12 pm
Forum: 8 BIT CORNER
Topic: 65XE boot issues
Replies: 34
Views: 8130

65XE boot issues

Hello Ziggy, Don't worry, to learn one needs to ask questions. And you're right, a lot of this stuff is easy for me. I've been repairing the 600XL and 800XL since they were introduced in Netherlands. (As an Atari employee) Moreover, the MMU file I sent is in German. That may complicate matters. So f...

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