Search found 174 matches

by Erm
Sat Sep 26, 2020 12:36 pm
Forum: ZX Spectrum Lounge
Topic: 128k +2 Mysterious Videos issue.
Replies: 15
Views: 344

Re: 128k +2 Mysterious Videos issue.

I'll certainly try that. When the board is out it's easy to get a finger under it while it's on.
by Erm
Wed Sep 23, 2020 10:07 pm
Forum: ZX Spectrum Lounge
Topic: 128k +2 Mysterious Videos issue.
Replies: 15
Views: 344

Re: 128k +2 Mysterious Videos issue.

Multimeter and PC Oscilloscope. Noticed with the QL-VGA that the waving corruption is even worse when you change the screen colour to something other than white. Black was ok, unless that's changed since the re-cap.
by Erm
Wed Sep 23, 2020 9:23 pm
Forum: ZX Spectrum Lounge
Topic: 128k +2 Mysterious Videos issue.
Replies: 15
Views: 344

Re: 128k +2 Mysterious Videos issue.

If you enter the 128K or 48K editor, does this make any difference to the symptoms? Also if possible can you use your RGB to SCART lead, at least until the fault/problem is found. On that subject, have you tried it on another display? Mark 48k mode makes no difference. Reverted to the RGB Scart lea...
by Erm
Wed Sep 23, 2020 6:01 pm
Forum: SALES
Topic: RS232 Interface (8255 Chip) £30
Replies: 4
Views: 172

Re: RS232 Interface (8255 Chip) £30

Thanks both. In that case I may as well bundle it with my other centronics items.
by Erm
Wed Sep 23, 2020 2:37 pm
Forum: ZX Spectrum Lounge
Topic: 128k +2 Mysterious Videos issue.
Replies: 15
Views: 344

Re: 128k +2 Mysterious Videos issue.

I changed C45, C47, C32 and C3 - no difference. C41 seemed to be way out (25µF instead of 100) so thought that may be an issue - changed it and C23, no change. So I swapped out all the electrolytics and it's still got the same fault. There did used to be an occasional jumpiness of the pic, particula...
by Erm
Tue Sep 22, 2020 8:02 pm
Forum: SALES
Topic: RS232 Interface (8255 Chip) £30
Replies: 4
Views: 172

RS232 Interface (8255 Chip) £30

On offer here for £30 plus whatever postage costs, is a ZX81 RS232 interface. Manufacturer unknown (it's most probably a German made product - Weidner is on the PCB). It uses a National Semiconductor INS8255N chip to do the business. I cannot test it, but if it doesn't work I'll gladly take it back....
by Erm
Tue Sep 22, 2020 7:59 pm
Forum: SALES
Topic: Memopak Centronics Interface, plus another.
Replies: 15
Views: 287

Re: Memopak Centronics Interface, plus another £70.

Hello. For sale here is a Memotek I/F Centronics Type Parallel Printer Interface plus what looks to be a home/kit made Centronics Interface of some kind. The Memotek device: is in excellent condition, gorgeous satin black metal with hardly a mark on it. The PCB inside also looks great. I don't have...
by Erm
Tue Sep 22, 2020 7:41 pm
Forum: SALES
Topic: Memopak Centronics Interface, plus another.
Replies: 15
Views: 287

Re: Memopak Centronics Interface, plus another.

XavSnap wrote: Tue Sep 22, 2020 7:06 pm Thanks to all contributors.
Pretty sure it was just me! ;)

If anyone finds this thread, the Memotek I/F Centronics device and the other related add-on are still for sale.
by Erm
Tue Sep 22, 2020 5:48 pm
Forum: SALES
Topic: Memopak Centronics Interface, plus another.
Replies: 15
Views: 287

Re: Memopak Centronics Interface, plus another.

Just about to email you the new version...

Let me know how that is.
by Erm
Mon Sep 21, 2020 9:38 pm
Forum: SALES
Topic: Memopak Centronics Interface, plus another.
Replies: 15
Views: 287

Re: Memopak Centronics Interface, plus another.

Ok, I loaded the dump program and it reported 0/0.

I then did SAVE "DUMP" and recorded the result with Audacity (the zeddy I'm using has a beefed up output so the data looks great). I'm just about to email you the zipped .wav, which is just over 7mb.

Is that all you need?