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Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
... IC1 (ULA) pin 33 and IC2 (Z80 CPU) pin 20 (/IORQ ... IC1 (ULA) pin 33 and IC2 (Z80 CPU) pin 11 (+5V ... IC1 (ULA) pin 12 and IC2 (Z80 CPU) pin 16 (/INT ... -
Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
... IC1 (ULA) pin 33 and IC2 (Z80 CPU) pin 20 (/IORQ ... IC1 (ULA) pin 33 and IC2 (Z80 CPU) pin 11 (+5V ... IC1 (ULA) pin 12 and IC2 (Z80 CPU) pin 16 (/INT ... -
Yellow issue 4A keyboard madnessNote sure if this is a similar problem to the one CornishManicMiner has, but one of my yellow issue 4A boards is driving me crazy. I had it in variou…
... IC1 (ULA) pin 33 and IC2 (Z80 CPU) pin 20 (/IORQ ... IC1 (ULA) pin 33 and IC2 (Z80 CPU) pin 11 (+5V ... IC1 (ULA) pin 12 and IC2 (Z80 CPU) pin 16 (/INT ... -
Yellow issue 4A keyboard madnessNote sure if this is a similar problem to the one CornishManicMiner has, but one of my yellow issue 4A boards is driving me crazy. I had it in variou…
... IC1 (ULA) pin 33 and IC2 (Z80 CPU) pin 20 (/IORQ ... IC1 (ULA) pin 33 and IC2 (Z80 CPU) pin 11 (+5V ... IC1 (ULA) pin 12 and IC2 (Z80 CPU) pin 16 (/INT ... -
Yellow issue 4A keyboard madnessNote sure if this is a similar problem to the one CornishManicMiner has, but one of my yellow issue 4A boards is driving me crazy. I had it in variou…
... ) IC1 (ULA) pin 33 and IC2 (Z80 CPU) pin 11 (+5V ... -
Yellow issue 4A keyboard madnessNote sure if this is a similar problem to the one CornishManicMiner has, but one of my yellow issue 4A boards is driving me crazy. I had it in variou…
... ) IC1 (ULA) pin 33 and IC2 (Z80 CPU) pin 11 (+5V ... -
Finally got round to itFinally got round to giving my old speccy a close look. Details 1982 Issue 2 Seriel No 001 196193 Hmm... Followed the initial tests on You tube w…
... rail---850 ohm
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IC2 as the usual patch however ... -
Questions about GALsI'm working on an old danish floppy interface for the speccy ([url="http://allan.hoiberg.dk/eng/zx/"]CS-Disk[/url]) The original interface contain…
... [/img]
IC1 and IC2 are both 74LS138, The "IC ... -
Original Grey +2 Picture IssuesSo, I have my +2 connected to an old CRT TV, and the Speccy has been working fine. Decided to have a shift around, but once I moved the +2 i've lost…
Sounds like the internal +12v supply might have failed, if you have a multimeter check the voltage on pin 11 of the TEA2000 (IC2). If it's not reading close to 12v, you'll be looking to change transistors TR8 and TR9.
B -
Original Grey +2 Picture IssuesSo, I have my +2 connected to an old CRT TV, and the Speccy has been working fine. Decided to have a shift around, but once I moved the +2 i've lost…
... pin 11 of the TEA2000 (IC2). If it's not reading ... -
No video output from Spectrum +2 (light grey)Got a strange issue with my Spectrum +2 light grey edition. It was working fine then all of sudden it outputs a black screen while I was using it wit…
Check the +12V supply to IC2 (TEA 2000) on pin 11.< ... -
ZX Spectrum 48K it only shows colored barsHello, I'm new to the forum and I need help with a ZX Spectrum 48K which I bought recently unfortunately defective. I want to mention that before t…
... likely it is okay.
IC2 (CPU) is at least partly ... -
Opus Discovery "the big switch on" (after 20 years)I have a few of these Opus Discovery's with different Eproms in that have not been swiched for 15-20 years or so . I am in no rush to switch any on …
... Pin 6 : Connects to pin IC2
Pin 7 : Connects ... Pin 8 : Connects to pin IC2 :OK
Pin 9:: ... /> Pin 4 : Connects to IC2
Pin 5 : Connects ... /> Pin 7 : Connects to IC2
Pin 8 : Connects ... br /> Pin 10 Connects to IC2
Pin 11 : ... -
Recapping parts list needed for +2a power supplyHello I've recently acquired a +2a power supply. It works, but given the age I'd like to do some preventative maintenance and refurbish it. Does a…
... voltage due to overheating of IC2 (see note).
Sometimes a ... , is to remove T2 and IC2 from the heatsink, clean off ... . Then ensure that T2 and IC2 are firmly secured back on ... -
zx spectrum +2 no clock signal ??help me ...... looking at a specie +2 (original +2) it is the Z70700 issue 1 (uk one) i seem to have no clock,no display,no sound at all. it is sho…
[quote="1024MAK;968915"]IC2 (74HCU04), the section with an ...
