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Issue 2 issue (...)Just acquired an issue 2 Spectrum 48 K, selled as working board, not working keyboard. Before testing it with a psu I opened the case and discovered …
... Issue4 diagram, where without doubt ULA 6C001 or later(!!) is ... as a patch for the ULA but as a patch ... Dickens' which show a 5C112E ULA with transistor patch. My ... (which is mounted on the Z80) should still be used. ... second check. IC2 is the Z80, and pin 30 is ... -
Issue 2 issue (...)Just acquired an issue 2 Spectrum 48 K, selled as working board, not working keyboard. Before testing it with a psu I opened the case and discovered …
... the 5c112 ula, but without TR6, and resistor to z80 pin 11 ... to mount surely tr6 to z80, but why that resistor terminal ... -
Issue 2 issue (...)Just acquired an issue 2 Spectrum 48 K, selled as working board, not working keyboard. Before testing it with a psu I opened the case and discovered …
... ....
[QUOTE]and resistor to z80 pin 11 disconnected [/QUOTE] I ... +5V (large track) and A0 (Z80 p11) where should not be ... diode is provided (going to ULA pin33, IORQGE) that transports this ... -
Issue 2 issue (...)Just acquired an issue 2 Spectrum 48 K, selled as working board, not working keyboard. Before testing it with a psu I opened the case and discovered …
... with 6C001 ula:
the first depicts the z80 with broken ... -
Issue 2 issue (...)Just acquired an issue 2 Spectrum 48 K, selled as working board, not working keyboard. Before testing it with a psu I opened the case and discovered …
... a transistor soldered across the Z80, and at any point you ... replace that Z80 and/or place a socket ... way you can swap out Z80 without further touching that transistor ... resistor/diode combo across the ULA, but usually it's in ... -
Issue 2 issue (...)Just acquired an issue 2 Spectrum 48 K, selled as working board, not working keyboard. Before testing it with a psu I opened the case and discovered …
... resistor is placed between the Z80's A0 line and +12V ... be the max on a Z80 pin.... Someone else shine a ... on an Issue2 board with ULA 6C001E-6 which board had ... -
Issue 2 issue (...)Just acquired an issue 2 Spectrum 48 K, selled as working board, not working keyboard. Before testing it with a psu I opened the case and discovered …
... k resistor, same transistor on z80, same cap on r59, as ... pcb on left side of z80 ?! Is it maybe the patch ... the older than Your's ula version ? Or is related to ... -
Issue 2 issue (...)Just acquired an issue 2 Spectrum 48 K, selled as working board, not working keyboard. Before testing it with a psu I opened the case and discovered …
... k resistor, same transistor on z80, same cap on r59, as ... pcb on left side of z80 ?! Is it maybe the patch ... the older than Your's ula version ? Or is related to ... -
Z80 Machine Code Question...Hi Folks, I know not strictly a BASIC question but I have started to learn Z80 machine code - 25 years too late! :smile: I have been reading a book…
... where you single-step through Z80 instructions, and you can ... easier to understand what the Z80 code is doing. Also ... R[/B] makes the Z80 repeat that until BC reaches ... When the ULA doesn't interfere with the Z80 (outside 4000 ... on a 3.58 MHz Z80. That's entire upper ... -
Mr Do! ?Not exactly a new idea (at least twenty-seven years old now :-o), but how about a port of Mr Do! to the Spectrum? There was never an official one, ev…
... the screen attributes of the ULA.
The game maps ... to copy it while the ULA is drawing the lower border ... messes them up.
Z80 instructions that use just one ... ) 4T instructions will take one ULA scan-line precisely. A program ...
