Search found 179 matches

by 1024MAK
Mon Sep 17, 2018 8:48 am
Forum: Hardware
Topic: cant enter code or load game on ZX Spectrum 48k
Replies: 8
Views: 246

Re: cant enter code or load game on ZX Spectrum 48k

ZX Spectrum repairers that I know of:- Ian at Mutant Caterpillar http://www.mutant-caterpillar.co.uk/shop/ or https://www.sellmyretro.com/offer/details/sinclair-zx-spectrum-repair-service%21-fix-your-speccy%21-3875 Dave at http://www.tynemouthsoftware.co.uk/VintageComputers Zorn sometimes offers a r...
by 1024MAK
Sun Sep 16, 2018 7:47 am
Forum: Hardware
Topic: cant enter code or load game on ZX Spectrum 48k
Replies: 8
Views: 246

Re: cant enter code or load game on ZX Spectrum 48k

Sorry Jake, your ZX Spectrum has a hardware fault. Your TV may or may not be cropping the video image from the ZX Spectrum, but as the outer part of the displayed image from a ZX Spectrum is the border area, I think it to be unlikely that the TV is cropping such a huge amount of the screen image. Se...
by 1024MAK
Fri Sep 14, 2018 8:33 pm
Forum: Website
Topic: Forum posts: grammar and punctuation
Replies: 18
Views: 304

Re: Forum posts: grammar and punctuation

Um, ah, oh. As long as we can understand what you are saying (at least, I think that we may want to understand what you are saying...) it doesn't really matter... :mrgreen: One of the most important concepts that no one told me (at least, I don't think anyone told me), is that in real speech, there ...
by 1024MAK
Wed Sep 12, 2018 3:39 pm
Forum: Sinclair Miscellaneous
Topic: 16K software, run faster with Russian clones?
Replies: 8
Views: 324

Re: 16K software, run faster with Russian clones?

One point that I don't remember seeing mentioned: the 'lower' 16K is contended only during the time the ULA is drawing the screen or during I/O port operations. So a clever programmer can sometimes arrange for all the time critical code to run during the time when contention does not occur, such as ...
by 1024MAK
Sun Sep 02, 2018 5:56 pm
Forum: Hardware
Topic: Have I killed my ZX Spectrum?
Replies: 7
Views: 551

Re: Have I killed my ZX Spectrum?

Well done :D

Have fun with your repaired Speccy 8-)

Mark
by 1024MAK
Wed Aug 29, 2018 11:49 pm
Forum: Hardware
Topic: Power Supplies
Replies: 7
Views: 280

Re: Power Supplies

The Sinclair ZX Spectrum 16k, 48k and Spectrum+ machines use DRAM chips that need three DC supplies: +5V +12V -5V The video circuitry also needs a +12V supply. The rest of the machine runs off the +5V supply. So how did Sinclair do it, given that the external power supply unit (PSU) is only rated fo...
by 1024MAK
Sat Aug 25, 2018 8:51 pm
Forum: Hardware
Topic: Brand new r2 48kB, not quite working
Replies: 42
Views: 1317

Re: Brand new r2 48kB, not quite working

Excellent news :D

Mark
by 1024MAK
Thu Aug 23, 2018 11:52 am
Forum: Hardware
Topic: Brand new r2 48kB, not quite working
Replies: 42
Views: 1317

Re: Brand new r2 48kB, not quite working

...although I had to make some substitutions: the resistor's a 120R, the transistor is an off-the-shelf 'general purpose' PNP (which the article said should be fine). Do any of these values actually matter? Well... maybe... In theory, a transistor rated for HF (high frequency) signals should be use...
by 1024MAK
Thu Aug 23, 2018 12:11 am
Forum: Hardware
Topic: Spectrum +3 missing menu screen
Replies: 2
Views: 163

Re: Spectrum +3 missing menu screen

If/when it gets to what is known as the copyright screen, does typing keys produce anything on screen? It is most likely to be a hardware fault with either a RAM chip, or the circuitry that selects which part of which ROM chip is active. Or maybe it is a relatively simple fix, such as a fault in the...
by 1024MAK
Wed Aug 22, 2018 11:02 pm
Forum: Hardware
Topic: Brand new r2 48kB, not quite working
Replies: 42
Views: 1317

Re: Brand new r2 48kB, not quite working

Odd. Is the Sony a multistandard monitor? If yes, does it have manual or automatic switching? And if automatic, is there a way to force it to PAL I standard? (that's I as in aye!). Or maybe just the PAL 50Hz setting. Some multistandard monitors and TVs sometimes get confused by the Spectrums video o...