Search found 100 matches

by balford
Wed Feb 03, 2016 6:24 pm
Forum: Hardware
Topic: ZXPand firmware (paging SirMorris!)
Replies: 24
Views: 3904

Re: ZXPand firmware (paging SirMorris!)

New GAL's arrived today, and I'm glad to report that after a new EPROM, SRAM and memory GAL, this ZXPand is now fully operational.

Thanks to all who helped, especially SirMorris :)

B
by balford
Mon Jan 18, 2016 6:38 pm
Forum: Hardware
Topic: ZXPand firmware (paging SirMorris!)
Replies: 24
Views: 3904

Re: ZXPand firmware (paging SirMorris!)

Got the replacement SRAM today, and the ZXPand boots with just the SRAM and modified Memory GAL, and PRINT PEEK 16389 = 128.

Once the GAL's arrive I'm confident I'll be able to resurrect this one :)

B
by balford
Fri Jan 15, 2016 12:39 pm
Forum: Hardware
Topic: ZXPand firmware (paging SirMorris!)
Replies: 24
Views: 3904

Re: ZXPand firmware (paging SirMorris!)

With Sirmorris' help, I've diagnosed the following: - Dead EPROM - Dead SRAM - Dead I/O GAL The PIC and the memory GAL are still good, however. Replacements incoming, however the GAL's are coming from China which will slow the repair work up somewhat. I'll report back when I return to this, but in t...
by balford
Thu Jan 14, 2016 1:32 pm
Forum: Hardware
Topic: ZXPand firmware (paging SirMorris!)
Replies: 24
Views: 3904

Re: ZXPand firmware (paging SirMorris!)

That would be great, cheers :) PM incoming...

B
by balford
Wed Jan 13, 2016 1:13 pm
Forum: Hardware
Topic: ZXPand firmware (paging SirMorris!)
Replies: 24
Views: 3904

Re: ZXPand firmware (paging SirMorris!)

Naturally the only 28C64 I have spare has a fault with its A0 address line :x

The PSU is good :)

Seems the SRAM is also bad, so ordered one of those too. The ZXPand is a purely digital board, so I'm fairly confident a new SRAM and EPROM will have it working again.

B
by balford
Tue Jan 12, 2016 11:04 pm
Forum: Hardware
Topic: Confirming a 2C158e ULA
Replies: 4
Views: 1043

Re: Confirming a 2C158e ULA

Fwapp wrote:Thanks B, I'll check that out when he sends it down, he doesn't have much luck with hardware (Mick ;) )
Ah, Mick :) He's cursed :D

B
by balford
Tue Jan 12, 2016 8:46 pm
Forum: Hardware
Topic: Confirming a 2C158e ULA
Replies: 4
Views: 1043

Re: Confirming a 2C158e ULA

In my experience (and from what I've read), 2C158E ULA's typically skew the first pixel line of output to the right when warmed up (best seen with a line of inverse characters printed to the top).

He could try this test and if the characters skew then it's almost certainly a late 158E.

B
by balford
Tue Jan 12, 2016 2:40 pm
Forum: Hardware
Topic: ZXPand firmware (paging SirMorris!)
Replies: 24
Views: 3904

Re: ZXPand firmware (paging SirMorris!)

Thanks, I mention version 6.7 as that's what my EPROM was marked with :) I have a 27C64 on order, but thanks for the offer :) I was just wondering if a 28C64 would work in its place as I see mention of it in early ZXPand development threads, but this may have changed with later board issues and I wa...
by balford
Tue Jan 12, 2016 10:40 am
Forum: Hardware
Topic: ZXPand firmware (paging SirMorris!)
Replies: 24
Views: 3904

ZXPand firmware (paging SirMorris!)

Hi, Using my ZXPand yesterday evening, the current consumption shot up to over 2A (I use a voltage/current module in series with my PSU to monitor stuff like this). I immediately powered off, but long story short, the ZXPand now refuses to work (verified on another Zeddy to be sure it's not the syst...
by balford
Sat Jan 09, 2016 11:37 pm
Forum: Hardware
Topic: BASICare microsystem
Replies: 6
Views: 996

Re: BASICare microsystem

Agreed - Mark is your man for this kind of work :)

B