Search found 32 matches

by Dukes909
Thu Feb 25, 2021 4:44 am
Forum: Hardware
Topic: No luck with my purchases
Replies: 1
Views: 174

No luck with my purchases

So I bought a "working" Timex Sinclair 1000 from the interweb, hopefully can use to test my non-working ZX81 (see previous post). Plug it in, power it up and... black screen! Boooooo! But it is different than the grey/white screen on my Z. Maybe I can swap chips and come up with something working. O...
by Dukes909
Wed Feb 24, 2021 5:31 am
Forum: Sinclair Misc
Topic: Over the top
Replies: 3
Views: 272

Re: Over the top

Ahh, they’re trying to recover the cost of the shrink wrapping machine :mrgreen:
Heehee I was thinking the same, like how did they get the plastic on there.. :lol:
by Dukes909
Tue Feb 23, 2021 3:50 pm
Forum: Sinclair Misc
Topic: Over the top
Replies: 3
Views: 272

Over the top

Disclaimer: this is not mine. I am still trying to get a T/S or ZX81 for a reasonable price to diagnose the first one (see my Hardware post(s)) I bought in December that is not working. eBay prices are crazy right now for retro stuff but this is over the top?... https://www.ebay.com/itm/324495208870...
by Dukes909
Sun Feb 14, 2021 12:24 am
Forum: Hardware
Topic: Metal strap purpose and why don't they all have one?
Replies: 3
Views: 268

Metal strap purpose and why don't they all have one?

So I am still stuck with my non working ZX81 ( https://www.sinclairzxworld.com/viewtopic.php?f=7&t=4043 ) until I get a second one from eBay to swap parts with. In the meantime I am diddling around with this one and wondering what the big metal strap across the bottom of the board is for. Why do som...
by Dukes909
Tue Feb 09, 2021 4:03 am
Forum: Hardware
Topic: Are TS1000 <-> ZX81 parts interchangeable?
Replies: 17
Views: 695

Re: Are TS1000 <-> ZX81 parts interchangeable?

Ok well I don’t have one yet but the TS1000 seem to go for less than the ZX81’s. I may buy one now knowing I can do this (unless there is another source for replacement components???) Direct like for like components, or rather, the chips is a bit tricky. New old stock/secondhand/pulled/used NMOS Z8...
by Dukes909
Tue Feb 09, 2021 3:55 am
Forum: Hardware
Topic: It was working until it stopped
Replies: 18
Views: 1223

Re: It was working until it stopped

Well, I don't know if it is progress or not, but after cleaning the contacts on the motherboard, then removing and cleaning each pin on each chip and reinstalling, I now get a screen of solid black & white bars rather than the solid white. https://i.postimg.cc/z3WRHpGV/F021-DEB2-2044-4249-BEDB-AEC57...
by Dukes909
Tue Feb 09, 2021 1:25 am
Forum: Hardware
Topic: It was working until it stopped
Replies: 18
Views: 1223

Re: It was working until it stopped

Do you know if your 16k RAM pack works okay? Yes, it does, or at least it worked the very first day I received this and I used some code from this board to display the following and posted my Hoorays on the Welcome board, and then the dreaded wonky screen happened and I haven't been able to get "K"...
by Dukes909
Tue Feb 09, 2021 1:13 am
Forum: Hardware
Topic: It was working until it stopped
Replies: 18
Views: 1223

Re: It was working until it stopped

Because of the (apparently) non-repetitive signals from the address and data pins, the automatic/autoset setting (not the automatic sweep which is completely different) on most ‘scopes gets confused. That’s why I think some of your traces appear distorted or fuzzy. The ‘scope is switching to either...
by Dukes909
Mon Feb 08, 2021 11:04 pm
Forum: Hardware
Topic: Are TS1000 <-> ZX81 parts interchangeable?
Replies: 17
Views: 695

Re: Are TS1000 <-> ZX81 parts interchangeable?

Also, forgot to say all chips on my issue one are socketed.
by Dukes909
Mon Feb 08, 2021 11:01 pm
Forum: Hardware
Topic: Are TS1000 <-> ZX81 parts interchangeable?
Replies: 17
Views: 695

Re: Are TS1000 <-> ZX81 parts interchangeable?

Ok well I don’t have one yet but the TS1000 seem to go for less than the ZX81’s. I may buy one now knowing I can do this (unless there is another source for replacement components???) For a normal production ZX81 that uses a mask ROM, apart from the RAM chips, the remaining chips are interchangeable...